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Previous Article | Next Article 
The Journal of Neuroscience, April 1, 2003, 23(7):2804
A Chondroitin Sulfate Proteoglycan PTP /RPTP Regulates the
Morphogenesis of Purkinje Cell Dendrites in the Developing Cerebellum
Masahiko
Tanaka1,
Nobuaki
Maeda2, 3,
Masaharu
Noda2, and
Tohru
Marunouchi1
1 Division of Cell Biology, Institute for Comprehensive
Medical Science, Fujita Health University, Toyoake, Aichi 470-1192, Japan, 2 National Institute for Basic Biology, Graduate
University for Advanced Studies, Okazaki, Aichi 444-8585, Japan, and
3 Tokyo Metropolitan Institute for Neuroscience, Fuchu,
Tokyo 183-8526, Japan
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ABSTRACT |
PTP /RPTP , a receptor-type protein tyrosine phosphatase
synthesized as a chondroitin sulfate (CS) proteoglycan, uses a
heparin-binding growth factor pleiotrophin (PTN) as a ligand, in which
the CS portion plays an essential role in ligand binding. Using an
organotypic slice culture system, we tested the hypothesis that
PTN-PTP signaling is involved in the morphogenesis of Purkinje cell
dendrites. An aberrant morphology of Purkinje cell dendrites such as
multiple and disoriented primary dendrites was induced in slice
cultures by (1) addition of a polyclonal antibody against the
extracellular domain of PTP , (2) inhibition of protein tyrosine
phosphatase activity, (3) enzymatic removal of the CS chains, (4)
addition of exogenous CS chains, and (5) addition of exogenous PTN, all of which disturb PTN-PTP signaling. These treatments also reduced the immunoreactivity to GLAST, a glial glutamate transporter, on
Bergmann glial processes. Furthermore, a glutamate transporter inhibitor also induced the abnormal morphogenesis of Purkinje cell
dendrites. Altogether, these findings suggest that PTN-PTP signaling
regulates the morphogenesis of Purkinje cell dendrites and that the
mechanisms underlying that regulation involve the GLAST activity in
Bergmann glial processes.
Key words:
PTP /RPTP ; pleiotrophin; GLAST; Purkinje cell; dendritic morphogenesis; cerebellum; organotypic slice culture
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Introduction |
Neurons are characterized by the
specific morphology of dendritic trees and axons, which are essential
for information processing. Although the molecular mechanisms of
directed axonal outgrowth are beginning to be elucidated, those
underlying the morphogenesis of dendritic trees are poorly understood.
Among the neurons of the CNS, the cerebellar Purkinje cells have the
most elaborate dendritic trees. Mature Purkinje cells have a single
primary dendrite, which extends toward the pial surface, branches
extensively in the molecular layer (ML), and makes synaptic contacts
with parallel fibers, the axons of granule cells. The presence and
differentiation of granule cells are necessary for normal development
of Purkinje cell dendrites, as shown in agranular cerebella of
x-irradiated and mutant animals (Altman and Anderson, 1972 ; Rakic and
Sidman, 1973 ; Sotelo, 1975 ; Berry et al., 1978 ). Coculture experiments using dissociated Purkinje cells and granule cells clearly indicated that the granule-Purkinje cell interaction plays a crucial role in the
branching and thickening of the Purkinje cell dendrites (Baptista et
al., 1994 ; Hirai and Launey, 2000 ). It has been suggested that granule
cells exert trophic effects on Purkinje cells by providing neurotrophic
substances and electrical activity (Schwartz et al., 1997 ; Hirai and
Launey, 2000 ). Although Purkinje cells displayed stimulated growth of
dendrites in such coculture systems, most of them had multiple primary
dendrites extending in various directions in contrast to Purkinje cells
in vivo having a single primary dendrite extending in only
one direction. This suggests that the polarity of Purkinje cells is
determined by alternative mechanisms. Recently, Yamada et al. (2000)
found that the lamellate processes of Bergmann glia surrounded the
differentiating dendritic trees of Purkinje cells, and more
importantly, the growing tips of Purkinje cell dendrites entered the
external granular layer (EGL) by contacting the rod-like processes of
Bergmann glia. These observations suggest that the Bergmann
glia-Purkinje cell interaction is involved in the directed growth and
determination of polarity of Purkinje cell dendrites.
Phosphacan/6B4 proteoglycan, a chondroitin sulfate (CS) proteoglycan
expressed predominantly in the CNS, is distributed around the cell
surface of Purkinje cells during dendritic outgrowth (Maeda et al.,
1992 ). Phosphacan corresponds to the extracellular domain of
PTP /RPTP , a receptor-type protein tyrosine phosphatase composed
of an N-terminal carbonic anhydrase-like domain, a fibronectin type III
domain, a serine-, glycine-rich domain, a transmembrane segment, and
two intracellular tyrosine phosphatase domains (Maurel et al., 1994 ;
Peles et al., 1998 ). Phosphacan and the transmembrane-type molecules
are generated by alternative splicing, and all of the splice variants
are synthesized as CS proteoglycans (Maurel et al., 1994 ; Nishiwaki et
al., 1998 ; Peles et al., 1998 ). Pleiotrophin (PTN) and midkine (MK),
closely related heparin-binding growth factors, bind to
PTP /phosphacan with high affinity and trigger signal transduction of
this receptor (Maeda et al., 1996 , 1999 ). The CS portion of
PTP /phosphacan plays an essential role in binding to PTN and MK, and
the removal of CS chains from PTP /phosphacan resulted in a marked
decrease of the binding affinity to PTN and MK and in the loss of
signal transduction (Maeda et al., 1996 , 1999 ; Qi et al., 2001 ).
Although Purkinje cells and Bergmann glia express PTP /phosphacan
(Canoll et al., 1993 ; Snyder et al., 1996 ), PTN and MK distribute along
Bergmann glial fibers in postnatally developing cerebellum (Matsumoto
et al., 1994 ; Wewetzer et al., 1995 ). These expression patterns suggest
that PTN/MK secreted by Bergmann glia binds with PTP on Purkinje
cells or Bergmann glia, or both. Thus, the signaling of
PTP /phosphacan and PTN/MK could be involved in cell-cell
interaction between Purkinje cells and Bergmann glia.
In this study, we hypothesized that PTN-PTP signaling is involved in
the Bergmann glia-Purkinje cell interaction required for the
morphogenesis of Purkinje cell dendrites. To test this hypothesis, we
used organotypic slice cultures of postnatal rat cerebellum, which
preserve the cytoarchitecture of the cerebellar cortex and reproduce
the series of processes in cerebellar cortical development (Tanaka et
al., 1994 ). Using this system, we found that the perturbation of
PTN-PTP signaling resulted in a marked increase in the number of
Purkinje cells with abnormal dendrites, such as multiple and
disoriented primary dendrites, showing that PTN-PTP signaling is
involved in the morphogenesis of Purkinje cell dendrites. Furthermore,
we obtained evidence suggesting that Bergmann glia play important roles
in these mechanisms.
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Materials and Methods |
Slice culture. The methods for slice culture have
been described previously (Tanaka et al., 1994 ). In brief, cerebella
were dissected from 9-d-old Wistar rats. The vermes of the cerebella were cut parasagittally into ~600-µm-thick slices in calcium- and
magnesium-free PBS (CMF-PBS). The slices were mounted on a collagen-coated, porous (2.0 µm) polycarbonate membrane (Nuclepore; Whatman, Clifton, NJ) that was floated at the interface
between the air and culture medium in a Petri dish ("interface"
culture technique) (Freshney, 1987 ; Yamamoto et al., 1989 ; Stoppini et al., 1991 ; Tanaka et al., 1994 ). The culture medium consisted of 15%
heat-inactivated horse serum (Invitrogen, Grand Island, NY), 25% Earle's balanced salt solution, 60% Eagle's basal medium, 5.6 gm/l glucose, 3 mM
L-glutamine, 5 µg/ml bovine insulin, 5 µg/ml
human transferrin, 30 nM sodium selenite, 20 nM progesterone, 1 mM
sodium pyruvate, 50 U/ml penicillin G potassium, and 100 µg/ml
streptomycin sulfate. The rabbit polyclonal antibody ( 6B4PG) against
the extracellular domain of PTP (PTP -ECD) has been described previously (Maeda et al., 1996 ). The other reagents added to the culture medium were purchased as follows: rabbit IgG, from
Chemicon (Temecula, CA); sodium orthovanadate, from
Wako Pure Chemicals (Osaka, Japan); chondroitinase ABC
(Chase ABC; protease free), CS-C and CS-D from shark cartilage, CS-E
from squid cartilage, and CS-A from whale cartilage, from Seikagaku
(Tokyo, Japan); recombinant human PTN, from Sigma (St.
Louis, MO); and
DL-threo- -benzyloxyaspartate (DL-TBOA), from Tocris (Bristol, UK). Chase ABC
was dissolved (6 U/ml) in 60 mM sodium acetate,
pH 7.5, 80 mM sodium chloride, and bovine serum
albumin (1 mg/ml), and stored as frozen aliquots. These reagents were
added at 1 d in vitro (DIV). The cultures were
incubated at 33°C in 5% CO2/95% air.
Because a large number of cells degenerated in the bottom part (medium
side) of the slice cultures, we analyzed the top half (air side) to
obtain data in the present study.
Analysis of the Purkinje cell morphology. For
immunohistochemistry of inositol 1,4,5-trisphosphate receptor
(IP3R), cerebellar slice cultures were fixed with
4% paraformaldehyde in CMF-PBS for 20 min at room temperature. For
analysis of the cerebellum in vivo, 250-µm-thick slices
were prepared from the vermes of the cerebella of 9- or 15-d-old rats
and fixed as mentioned above. The slices were preincubated for 30 min
in 10% normal goat serum and 0.3% Triton X-100 in
CMF-PBS and then incubated overnight at 4°C in CMF-PBS containing a
rat anti-mouse IP3R monoclonal antibody (4C11;
1:20) (Maeda et al., 1989 ). The immunoreactivity was visualized using a
Cy3-conjugated goat anti-rat IgG antibody and examined under a confocal
laser scanning microscope (LSM510; Zeiss, Oberkochen,
Germany). For imaging of Purkinje cells, we used a 63× water-immersion
objective (numerical aperture = 0.9; Achroplan Water;
Zeiss) and projected five to eight optical sections of 3 µm thickness to make one stacked image. For analysis of the morphology of primary dendrites, we used three to four slices from
three independent experiments in each experimental condition and
randomly selected 222-300 (in vivo) and 32-63 (slice
cultures) Purkinje cells per slice [total 707-729 (in
vivo) and 126-205 (slice cultures) cells per condition]. For
statistical analysis of the ratios of the three types of Purkinje cells
(see Results), the repeated measures ANOVA was used.
Immunohistochemistry of cryosections. For
immunohistochemical analysis of IP3R, PTP ,
GLAST, PTN, CS, neuronal nuclei (NeuN), vesicular glutamate
transporter 1 (VGLUT1), and glial fibrillary acidic protein (GFAP),
cerebellar slices before or after culture were fixed with 4%
paraformaldehyde in CMF-PBS for 20 min at room temperature, frozen in
liquid nitrogen, and sectioned at 12 µm on a cryostat. The sections
were preincubated for 30 min at room temperature in 10% normal goat
serum in CMF-PBS with or without 0.3% Triton X-100, and
then incubated overnight at 4°C in CMF-PBS containing a rat
anti-IP3R monoclonal antibody (4C11; 1:20), a rabbit anti-PTP -ECD antibody ( 6B4PG; 20 µg/ml), a mouse
monoclonal antibody against the intracellular domain of PTP
(PTP -ICD) (Transduction Laboratories, Lexington, KY;
1:100), a rabbit anti-GLAST antibody (Abcam, Cambridge,
MA; 1:600), a guinea pig anti-GLAST antibody (Chemicon;
1:8000), a goat anti-PTN antibody (N-15; Santa Cruz Biotechnology,
Santa Cruz, CA; 1:400), a mouse anti-CS monoclonal antibody (CS-56;
Sigma; 1:800), a mouse anti-NeuN monoclonal antibody (Chemicon; 1:600), a guinea pig anti-VGLUT1 antibody
(Chemicon; 1:10,000), or a rabbit anti-GFAP antibody
(Immunon, Shandon, Pittsburgh, PA; 1:1000). For
pretreatment with Chase ABC before PTN immunohistochemistry, the
sections were incubated for 40 min at 37°C in CMF-PBS containing 20 mU/ml Chase ABC. The immunoreactivities to IP3R,
PTP -ECD, GLAST (rabbit antibody), NeuN, and GFAP were visualized
using Cy3-, Cy2-, or Cy5-conjugated secondary antibodies. The
immunoreactivities to PTP -ICD, GLAST (guinea pig antibody), and PTN
were visualized with a tyramide signal amplification system
(TSA-Indirect; NEN Life Science Products, Boston, MA) and
Cy2-conjugated streptavidin. Images for fluorescent microscopy were
acquired with a confocal laser scanning microscope (LSM510;
Zeiss). In some cases of PTN immunohistochemistry, the
signals were chromogenically visualized with 3-amino-9-ethylcarbazole
(AEC). The immunoreactivities to CS and VGLUT1 were visualized by the
streptavidin-biotin affinity method and development with AEC.
Quantitative analysis of Purkinje and granule cells and Bergmann
fibers. For measurement of the length of the longest dendrite per
cell and counting the number of dendritic branching points per cell,
the stacked confocal microscopic images of Purkinje cells obtained as
described above were analyzed using the LSM Ver. 2.8 software
(Zeiss). For evaluation of the density of Purkinje and
granule cells, cryosections of slice cultures were stained by
immunohistochemistry using antibodies against
IP3R and NeuN as described above. The
IP3R- and NeuN-positive cells within 150 µm of
the Purkinje cell layer (PL) and internal granular layer (IGL) were
enumerated to determine the density of Purkinje and granule cells,
respectively, in confocal microscopic images of 2-µm-thick optical
sections. As another type of evaluation of granule cell density, the
number of NeuN-positive cells within square areas of 100 × 100 µm2 of the IGL was counted. We did these
two types of evaluation of granule cell density because migration of
these cells from the EGL to the IGL might result in an increase of only
one of the number of granule cells per unit length of the IGL and that per unit area of the IGL in slice cultures. When counting the NeuN-positive cells, the cells >10 µm in diameter (<0.1% of total NeuN-positive cells in the IGL) were not included because they might be
Golgi cells. For evaluation of Bergmann fibers, GFAP-positive fibers
>30 µm within 150 µm of the ML were enumerated in confocal microscopic images of 3-µm-thick optical sections. Statistical analysis was done using Student's t test.
Western blotting. Slice culture and treatment with Chase ABC
or CS chains were done as described above. Three cultured slices at 3 DIV were combined and rapidly frozen on dry ice. The frozen slices were
homogenized in 200 µl of 1% NP-40, 0.1% SDS, 2 mM phenylmethylsulfonyl fluoride, 1.5 µM aprotinin, 30 µM
E64, 40 µM leupeptin, 100 µM bestatin, and 20 µM
pepstatin A. After centrifugation at 15,000 × g for 15 min at 4°C, the supernatants (15 µg protein) were applied to 12.5%
SDS-PAGE and Western blotting using a goat anti-PTN antibody
(R&D systems, Minneapolis, MN; 1:1,000). The density of the bands was
quantified by an Epson desktop scanner (GT-9700F) using NIH image software.
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Results |
Comparison of the morphogenesis of Purkinje cell dendrites
in vivo and in slice cultures
In the present study, we examined the morphogenesis of Purkinje
cell dendrites in postnatal cerebellar development using an organotypic
slice culture system of cerebellum from 9-d-old rats (Tanaka et al.,
1994 ). Purkinje cells were visualized by immunohistochemical staining
using a monoclonal antibody against IP3R (Maeda
et al., 1989 ). This antibody stains clearly the overall structure of
Purkinje cells, including dendrites, dendritic spines, axons, and cell bodies (Fig. 1).

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Figure 1.
Morphogenesis of Purkinje cell dendrites in
vivo and in slice cultures. A-C, Fluorescent
immunohistochemistry using a monoclonal antibody against
IP3R (4C11) showing the morphology of Purkinje cells in the
cerebellum from P9 (A, B) and P15
(C) rats. A, Low-power view of an
immunostained cryosection. B, C, Confocal
microscopic images of immunostained slices. The multiple primary
dendrite (MPD)-type (arrows) and single
primary dendrite (SPD)-type Purkinje cells coexist on P9
(B), whereas most Purkinje cells are of the SPD
type on P15 (C).
D-F, Overview (D)
and fluorescent immunohistochemistry using 4C11 (E,
F) of cerebellar slices derived from P9 rats and
cultured for 6 d under control conditions. E,
Low-power view of an immunostained cryosection. F, A
confocal microscopic image of an immunostained slice culture. Scale
bars: (in A) A, E, 100 µm; (in
B) B, C, F, 25 µm;
D, 1 mm. G, Quantitative representation
of the ratios of the three types of Purkinje cells in
vivo (P9 and P15) and in slice cultures at 6 DIV under control
conditions. The ratio of SPD-type Purkinje cells significantly
increased in slice cultures at 6 DIV compared with that on P9, although
the increase was not as marked as in vivo. Cell counts
were made in slices, not in cryosections, which enabled us to reliably
distinguish the morphology of Purkinje cell dendrites.
DOPD, Disoriented primary dendrite.
n = 4. Error bars represent SEM.
*p < 0.05, **p < 0.001 versus
P9.
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The morphology of Purkinje cell dendrites changes dramatically during
postnatal cerebellar development (Hendelman and Aggerwal, 1980 ;
Armengol and Sotelo, 1991 ). In the first postnatal week in
vivo, Purkinje cells have several primary dendrites. During the
second postnatal week, most Purkinje cells lose all of their primary
dendrites except one, which extends toward the pial surface, branches
extensively in the ML, and forms numerous synapses with parallel fibers
(Fig. 1A-C).
Our slice culture system preserves the overall structure of cerebellar
slices (Fig. 1D) and the cytoarchitecture of the
cerebellar cortex and reproduces the serial process of granule cell
development, including proliferation, migration, and extension of
parallel fibers within 6 DIV, as described previously (Tanaka et al.,
1994 ). Purkinje cells also survive well, are arranged in a row at the PL as in vivo (Fig. 1E), extend arborized
dendritic trees toward the pial surface (Fig. 1F),
and form synapses with parallel fibers (Tanaka et al., 1994 ).
As the first step in the present study, we carefully observed the
morphological changes of Purkinje cell dendrites in vivo and
in slice cultures under control conditions. The immunohistochemical analysis was done using slices, not sections (cryosections or paraffin
sections) of slices, which enabled us to reliably distinguish the
morphology of Purkinje cell dendrites. The morphology of Purkinje cells
was classified into three types: single primary dendrite (SPD),
multiple primary dendrite (MPD), and disoriented primary dendrite
(DOPD). The MPD type was defined as Purkinje cells with multiple
primary dendrites, all of which extended toward the pial surface. The
DOPD type was defined as Purkinje cells with multiple primary
dendrites, at least some of which had an abnormal orientation, for
example, extending horizontally in the PL or downward into the IGL. No
Purkinje cells with a single primary dendrite extending abnormally were
observed in the present study.
In the rat cerebellum on postnatal day (P) 9, approximately half
(47.9%) of the Purkinje cells were of the SPD type and half (49.6%)
were of the MPD type (Fig. 1B,G).
Few (2.5%) Purkinje cells were of the DOPD type. On P15, most
Purkinje cells showed the SPD-type morphology
(SPD/MPD/DOPD = 88.3:11.7:0.0%) (Fig. 1C,G). Also in our slice culture system, the
ratio of SPD-type Purkinje cells significantly increased at 6 DIV
compared with that on P9 (0 DIV), although somewhat fewer SPD-type and
more MPD-type cells were observed under the culture conditions than in
the P15 cerebellum (SPD/MPD/DOPD = 62.7:34.5:2.8%) (Fig.
1F,G). These results indicated that
nearly normal morphological changes of Purkinje cell dendrites occur in
our slice cultures under control conditions, although these changes
appeared to proceed insufficiently in vitro.
Expression patterns of PTP and PTN in postnatally
developing cerebellum
The expression pattern of PTP in P9 rat cerebellum was examined
by double-fluorescent immunohistochemistry using antibodies against
PTP -ECD or -ICD and IP3R (Fig.
2A,B).
Signals obtained by a polyclonal antibody against PTP -ECD were
abundant around Purkinje cells in the PL and ML (Fig.
2A). On the other hand, the immunoreactivity to the
monoclonal antibody against PTP -ICD was detected in the cytoplasm
and surroundings of Purkinje cells (Fig. 2B). Western
blotting showed that the amount of the transmembrane forms of PTP is
very low compared with that of the secreted form (data not shown),
which suggests that the signals of PTP -ECD mainly correspond to the
presence of the secreted form, phosphacan. In addition, the signals of
both PTP -ECD and -ICD were detected in the IGL and white matter.

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Figure 2.
Expression patterns of PTP and PTN in
postnatally developing cerebellum. A-C, Confocal
microscopic images of cerebellar cryosections derived from P9 rats and
double stained by fluorescent immunohistochemistry using antibodies
against the extracellular domain (ECD)
(A1) or the intracellular domain
(ICD) (B1, C1) of PTP (Cy2) and
IP3R (A2, B2) or GLAST (C2)
(Cy3). A3, B3, and
C3 are the merged images. The immunoreactivities to
PTP -ICD and GLAST partially overlapped each other, especially around
Purkinje cells. EGL, External granular layer;
ML, molecular layer; PL, Purkinje cell
layer; IGL, internal granular layer. Scale bar, 25 µm.
D, E, A cerebellar cryosection derived
from a P9 rat and stained by immunohistochemistry using an antibody
against PTN. E is the high-magnification image of the
enclosed area in D. PTN distributes abundantly in the
ML. Scale bars: D, 50 µm; E, 25 µm.
F, An adjacent section stained with toluidine blue.
Scale bar, 25 µm.
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During postnatal development of the cerebellum in vivo,
differentiating dendrites of Purkinje cells are surrounded by the lamellate processes of Bergmann glia, which express GLAST, a glial glutamate transporter (Yamada et al., 2000 ).
Double-fluorescent immunohistochemistry using antibodies
against PTP -ICD and GLAST showed that the immunoreactivities to
these proteins partially overlapped each other, especially around
Purkinje cells. This suggests that the PTP -ICD-positive structures
surrounding Purkinje cells were the GLAST-positive lamellate processes
of Bergmann glia (Fig. 2C).
Immunohistochemical analysis using an antibody against PTN revealed
that this growth factor shows a characteristic localization in the
developing cerebellum (Fig. 2D-F). PTN was
distributed abundantly in the ML and moderately in the IGL (Fig.
2E). Thus, signal transduction of PTP by PTN could
occur most strongly in the ML in the developing cerebellum. In
addition, abundant signals of PTN were also observed in the white matter.
Involvement of PTP in the morphogenesis of Purkinje
cell dendrites
From the abundant expression of PTP and PTN around developing
Purkinje cells, we hypothesized that PTN-PTP signaling is involved
in the morphogenesis of Purkinje cell dendrites. To test this
possibility, we examined the effects of the polyclonal antibody against PTP -ECD, 6B4PG, on the morphogenesis of Purkinje
cell dendrites in slice cultures. This antibody disturbs PTP
signaling activated by PTN and MK (Maeda et al., 1996 ; Maeda and Noda,
1998 ; Qi et al., 2001 ). On addition of this antibody (200 µg/ml) into the medium of slice cultures, the MPD (Fig.
3A) and DOPD (Fig. 3B) types of Purkinje cells significantly increased at 6 DIV
(SPD/MPD/DOPD = 32.4:48.4:19.2%) (Fig. 3F).
Notably, the DOPD type of Purkinje cells increased remarkably. Addition
of the control rabbit IgG (200 µg/ml) did not influence the
morphogenesis of Purkinje cells (SPD/MPD/DOPD = 62.0:34.1:3.9%)
(Fig. 3C,F). These findings suggest that
PTP regulates the morphogenesis of Purkinje cell dendrites during
cerebellar development. The length of the longest dendrites and the
number of branching points per cell were not significantly different
between the 6B4PG- and control IgG-added conditions, indicating that
the growth of Purkinje cell dendrites itself was not influenced by this
treatment (Table 1). Thus, PTP does
not simply promote growth of Purkinje cell dendrites but is involved in
the morphological change from the MPD- to the SPD-type Purkinje cells
and the directed growth of Purkinje cell dendrites.

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Figure 3.
Involvement of PTP in the morphogenesis of
Purkinje cell dendrites. A-E, Effects of the polyclonal
antibody against PTP -ECD ( 6B4PG) (A,
B), control IgG (C), and sodium vanadate
(D, E) on the morphogenesis of Purkinje cell dendrites.
Shown are confocal microscopic images of cerebellar slices derived from
P9 rats, cultured for 6 d with culture medium containing 6B4PG
(200 µg/ml) (A, B), control IgG (200 µg/ml)
(C), and sodium vanadate (10 µM)
(D, E) and stained by fluorescent
immunohistochemistry using 4C11. On addition of 6B4PG and sodium
vanadate, the MPD (A, D) and DOPD (B,
E) types of Purkinje cells markedly increased. Control IgG
did not influence the morphogenesis of Purkinje cell dendrites
(C). Scale bar, 25 µm. F, Quantitative
representation of the effects of 6B4PG, control IgG, sodium
vanadate, and phenylarsine oxide (PAO) on the morphogenesis
of Purkinje cell dendrites in slice cultures at 6 DIV.
n = 3 (Vanadate, PAO) or 4 ( 6B4PG, Control IgG). Error bars represent
SEM. *p < 0.05 versus control IgG (200 µg/ml);
**p < 0.005 versus control (data in Fig.
1G).
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Consistently, sodium vanadate and phenylarsine oxide, protein tyrosine
phosphatase inhibitors, also increased the MPD and DOPD types of
Purkinje cells at 6 DIV [SPD/MPD/DOPD = 25.4:63.3:11.4% (sodium
vanadate; 10 µM); 25.1:64.3:10.7% (phenylarsine oxide; 0.1 µM)] (Fig. 3D-F). We cannot
exclude the possibility that these treatments retarded Purkinje cell
development, however, because they concomitantly resulted in reduced
extension and branching of Purkinje cell dendrites [longest dendrite
per cell = 64.8 ± 3.1 µm (n = 41),
branching points per cell = 40.8 ± 6.0 (n = 16) under vanadate-added (compare Table 1)].
Involvement of CS and PTN in the morphogenesis of Purkinje
cell dendrites
CS plays essential roles in the signal transduction of
PTP , especially for the signaling of PTN and MK. As revealed by
immunohistochemistry using a monoclonal antibody against CS, CS-56,
this glycosaminoglycan is present in the ML, IGL, and white matter
in vivo (data not shown) and in slice cultures (Fig.
4A). Addition of Chase
ABC (200 mU/ml), an enzyme that hydrolyzes CS chains, into the medium of slice cultures markedly decreased the immunoreactivity to CS-56 (Fig. 4B). This treatment also resulted in a
significant increase in the MPD and DOPD types of Purkinje cells
(SPD/MPD/DOPD = 36.5:50.2:13.3%; compare SPD/MPD/DOPD = 63.7:31.6:4.6% under control conditions) (Fig.
4C,D,M), as in
the case of 6B4PG. These results indicated that endogenous CS is
involved in the morphogenesis of Purkinje cell dendrites.

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Figure 4.
Involvement of chondroitin sulfate
(CS) and PTN in the morphogenesis of Purkinje cell
dendrites. A, B, Distribution of CS in
the control (A) and chondroitinase ABC
(Chase ABC)-treated (B) slice
cultures. Cryosections of cerebellar slices derived from P9 rats,
cultured for 6 d without (A) or with
(B) Chase ABC (200 mU/ml), and stained by
immunohistochemistry using a monoclonal antibody against CS (CS-56).
Scale bar, 25 µm. C-J, Effects of Chase ABC, CS, and
PTN on the morphogenesis of Purkinje cell dendrites. Shown are confocal
microscopic images of cerebellar slices cultured for 6 d with
culture medium containing Chase ABC (200 mU/ml) (C,
D), CS-C (50 µg/ml) (E,
F), CS-A (50 µg/ml) (G,
H), and PTN (1 µg/ml) (I,
J), and stained by fluorescent
immunohistochemistry using 4C11. On addition of Chase ABC, CS-C, and
PTN, the MPD (C, E,
I) and DOPD (D, F,
J) types of Purkinje cells increased. In
contrast, many Purkinje cells had an SPD under the CS-A-added
conditions (G, H). Scale bar, 25 µm. K, L, High-power views of the
enclosed areas in D, H. Spine formation
on Purkinje cell dendrites did not differ between the Chase ABC
(K)- and CS-A (L)-added
conditions. Scale bar, 3 µm. M, Quantitative
representation of the effects of Chase ABC, CS, and PTN on the
morphogenesis of Purkinje cell dendrites in slice cultures at 6 DIV.
n = 3 (CS chains) or 4 (Control, Chase ABC,
PTN). Error bars represent SEM.
*p < 0.05, **p < 0.005 versus
control.
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Next we examined the effects of exogenously added CS chains. We
indicated previously that various CS samples differentially inhibit the
signaling of the PTN-PTP pathway (Maeda et al., 1996 , 1999 ).
Although CS-C, -D, and -E markedly inhibited the binding of PTN to
PTP , CS-A scarcely influenced the binding. A similar selectivity was
observed in the effects on the morphogenesis of Purkinje cell
dendrites. CS-C, -D, and -E (50 µg/ml) increased the MPD and DOPD
types of Purkinje cells when added to the medium of slice cultures
[SPD/MPD/DOPD = 36.2:57.9:5.9% (CS-C); 25.1:64.4:10.5% (CS-D);
42.6:46.1:11.2% (CS-E)] (Fig.
4E,F,M). In
contrast, the morphology of Purkinje cell dendrites was not influenced
by addition of 50 µg/ml CS-A (SPD/MPD/DOPD = 64.0:30.1:5.9%)
(Fig. 4G,H,M). These observations suggested that PTN signaling is involved in the
morphogenesis of Purkinje cell dendrites.
In our slice culture system, exogenously applied PTN also induced an
abnormal morphology in Purkinje cell dendrites (SPD/MPD/DOPD = 37.4:55.2:7.4%) (Fig.
4I,J,M). This may
be caused by perturbation of normal distribution of the endogenous PTN
by the exogenous PTN.
The morphological change of Purkinje cells from the MPD to the SPD type
is accompanied by the formation of many dendritic spines in
vivo. This later aspect of maturation appeared not to be
influenced by treatment with the reagents affecting PTN-PTP signaling in slice cultures. Spine formation was apparently normal in
the MPD and DOPD types of Purkinje cells in the slice cultures treated
with Chase ABC and CS chains (Fig.
4K,L).
In contrast to the dendrite formation of Purkinje cells, development of
granule cells proceeded normally even in the presence of the reagents
affecting PTN-PTP signaling. As under control conditions, migration
of granule cells from the EGL to the IGL was nearly completed by 6 DIV
in the treated cultures, as revealed by the almost complete
disappearance of the EGL (Fig.
5A,B).
The density of granule cells in the IGL at 6 DIV was not significantly different between the treated and control conditions (Fig.
5C,D, Table 2). No
abnormalities such as increased pyknosis were observed in granule cells
in sections of the treated cultures processed for Nissl staining (Fig.
5A,B) and immunohistochemistry
against NeuN (Fig. 5C,D). Furthermore, VGLUT1, a
vesicular glutamate transporter that is localized to the synaptic
vesicles (Bellocchio et al., 1998 ), was expressed in the ML under the
treated as well as control conditions, suggesting that normal
presynaptic structures of parallel fiber terminals were formed under
both conditions (Fig.
5E,F).

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Figure 5.
Development of granule cells in slice cultures
under control and CS-D-added conditions. Cerebellar slices cultured for
6 d without
(A,C,E) or
with
(B,D,F)
CS-D were processed for several histological analyses.
A, B, Nissl staining with toluidine blue.
Migration of granule cells from the EGL to the IGL was nearly completed
even in the CS-D-treated cultures. Scale bar, 50 µm.
C, D, Confocal microscopic images of
cryosections double stained by fluorescent immunohistochemistry using
antibodies against NeuN (Cy2, green) and
IP3R (Cy3, red). The density of granule
cells in the IGL was not significantly different between these two
conditions (Table 2). Scale bar, 25 µm. E,
F, Cryosections stained by immunohistochemistry using an
antibody against vesicular glutamate transporter 1 (VGLUT1). VGLUT1 was expressed in the ML under both
conditions. Scale bar, 50 µm.
|
|
Interestingly, Chase ABC digestion of the cerebellar sections
markedly reduced the PTN immunoreactivity in the ML (Fig.
6A,B), indicating that most of the endogenous PTN is present in a CS-bound form in this tissue. This also suggests that the effects of Chase ABC
and CS chains on the morphogenesis of Purkinje cell dendrites were
caused by the displacement of PTN from the ML. In fact, Western blotting showed that the addition of CS-D but not CS-A into the culture
medium markedly decreased the PTN contents in the cerebellar slices
[control/CS-D/CS-A = 100; 68 ± 8 (p < 0.01 vs control; t test); 100 ± 4%
(n = 3)] (Fig. 6C).

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Figure 6.
Effects of the Chase ABC and CS treatments on PTN
contents in the cerebellum. A, B,
Confocal microscopic images of adjacent cryosections derived from the
cerebellum of a P9 rat and stained by fluorescent immunohistochemistry
using an antibody against PTN without (A) or with
(B) pretreatment by Chase ABC (20 mU/ml; 37°C;
40 min). The pretreatment with Chase ABC reduced PTN immunoreactivity.
Scale bar, 25 µm. C, Western blotting analysis showing
effects of CS-D and -A on PTN contents in cerebellar slice cultures.
Addition of CS-D but not CS-A decreased the PTN contents in the
slices.
|
|
Involvement of GLAST on Bergmann glial processes
Because the GLAST-positive lamellate processes of Bergmann glia
expressed PTP , we next examined whether the reagents affecting PTN-PTP signaling influence these processes of Bergmann glia. For
this purpose, cryosections of cerebellar slice cultures were double
stained by immunohistochemistry using the antibodies against IP3R and GLAST. Although the cell bodies and
dendrites of Purkinje cells were surrounded by the GLAST-positive
lamellate processes of Bergmann glia in slice cultures under control
conditions (Fig. 7A,B),
the GLAST immunoreactivity was markedly reduced in the slice cultures
treated with 6B4PG, Chase ABC, and CS-C, -D, and -E (Fig.
7C,D). In contrast, the same treatments did not
reduce the number of Bergmann fibers, the shaft processes of Bergmann glia that express GFAP, a glial intermediate filament protein (Fig.
7E,F, Table
3). This indicated that the reduction in
GLAST immunoreactivity was not caused by the nonspecific
degeneration of Bergmann glia. Western blotting also showed that
the amount of GLAST but not GFAP was reduced by these
treatments (data not shown). These observations strongly suggest that
the morphogenesis of Purkinje cell dendrites involves their interaction
with the GLAST-positive lamellate processes of Bergmann glia.

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Figure 7.
Reduction in GLAST immunoreactivity
on Bergmann glial processes by the reagents affecting PTN-PTP
signaling. Shown are confocal microscopic images of cryosections of
cerebellar slices cultured for 6 d with culture medium containing
control IgG (A, B) and 6B4PG (C, D)
(200 µg/ml) and double stained by fluorescent immunohistochemistry
using antibodies against IP3R (A1, B1, C1,
D1) and GLAST (A2, B2, C2, D2). A3, B3,
C3, and D3 are the merged images. Although the
cell bodies and dendrites of Purkinje cells were surrounded by the
GLAST-positive lamellate processes of Bergmann glia under the control
IgG-treated conditions (B, arrowheads),
the GLAST immunoreactivity was markedly reduced under the
6B4PG-treated conditions (C, D). Scale bars: (in
A) A, C, 25 µm; (in
B) B, D, 5 µm.
E, F, Distribution of GFAP in cerebellar
slice cultures. Confocal microscopic images of cryosections of slices
cultured for 6 d without (E) or with
(F) CS-C (50 µg/ml) and stained by fluorescent
immunohistochemistry using an antibody against GFAP. The GFAP-positive
shaft processes of Bergmann glia did not differ between the two culture
conditions. Scale bar, 25 µm.
|
|
The reduction in GLAST immunoreactivity by the reagents affecting
PTN-PTP signaling suggests that the glutamate-transporting activity
of GLAST is involved in the morphogenesis of Purkinje cell dendrites
presumably downstream of PTN-PTP signaling. To test this hypothesis,
slice cultures were treated with DL-TBOA, an inhibitor of
glutamate transporters (Shimamoto et al., 1998 ). DL-TBOA
(10 µM) actually increased the MPD and DOPD types of
Purkinje cells (SPD/MPD/DOPD = 36.0:49.3:14.7%; compare
SPD/MPD/DOPD = 59.3:36.5:4.1% under control conditions) (Fig.
8). This treatment reduced neither the
survival of Purkinje cells [IP3R-positive cells
per 150 µm of the PL under DL-TBOA-added conditions = 4.4 ± 0.3 (n = 28) (compare Table 1)] nor the
extension or branching of Purkinje cell dendrites (Fig.
8A,B). Thus, the morphogenesis of
Purkinje cell dendrites may be regulated by the glutamate-transporting activity of GLAST on Bergmann glial processes.

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Figure 8.
Effects of a glutamate transporter inhibitor on
the morphogenesis of Purkinje cell dendrites. A,
B, Confocal microscopic images of cerebellar slices
derived from P9 rats, cultured for 6 d with culture medium
containing DL-threo- -benzyloxyaspartate
(TBOA) (10 µM), an inhibitor of glutamate
transporters, and stained by fluorescent immunohistochemistry using
4C11. On addition of DL-TBOA, the MPD
(A) and DOPD (B) types of
Purkinje cells increased. Scale bar, 25 µm. C,
Quantitative representation of the effects of DL-TBOA on
the morphogenesis of Purkinje cell dendrites in slice cultures at 6 DIV. n = 4. Error bars represent SEM.
*p < 0.05 versus control.
|
|
 |
Discussion |
The postnatal development of Purkinje cells is characterized by a
specific pattern of dendritic morphogenesis. The change of Purkinje
cells from the MPD or DOPD type to the SPD type strictly proceeds under
in vivo conditions, and almost all of the Purkinje cells are
of the SPD type in the matured cerebellum. In our organotypic slice
culture system of postnatal rat cerebellum, the morphological changes
of Purkinje cells basically proceeded as in vivo (Fig. 1).
This suggested that some of the primary dendrites were withdrawn in
slice cultures as in vivo. However, more MPD-type Purkinje cells were found in slice cultures at 6 DIV than in P15 cerebellum. In
addition, a significant population of Purkinje cells was of the DOPD
type at 6 DIV, whereas at the corresponding in vivo stage (P15), this type of Purkinje cell was not observed. We consider that
this insufficient progress of Purkinje cell development in slice
cultures is caused by a decrease in signal transduction levels required
for the dendrite formation under the culture conditions. However, it
seems that this property of the slice culture system makes it a highly
sensitive assay system for Purkinje cell development. Using this
culture system, we demonstrated that the perturbation of
PTN-PTP signaling induced the aberrant morphology of Purkinje cell
dendrites such as MPDs and DOPDs (Figs. 3, 4), clearly showing that
PTN-PTP signaling is involved in the morphogenesis of Purkinje cell
dendrites. Berry and Bradley (1976) reported that Purkinje cells
already acquire their polarity on P9. However, our findings that the
perturbation of PTN-PTP signaling induced the DOPD-type Purkinje
cells suggest that this signaling needs to function continuously to
maintain the polarity of Purkinje cells. If this signaling is lost, new
primary dendrites could sprout and extend to an abnormal orientation
even after P9.
CS proteoglycans are reported to contribute to the regulation of
directed axonal outgrowth of various neurons, including retinal ganglion cells (Brittis and Silver, 1994 ; Chung et al., 2000 ) and
spinal motor neurons (Bernhardt and Schachner, 2000 ). These findings suggest that the signal transductions mediated by CS proteoglycans are involved in the directed outgrowth of neurites, although it is not known what kinds of CS proteoglycans contribute to
these phenomena. The present study identified PTP as a CS proteoglycan regulating the dendritic morphogenesis of cerebellar Purkinje cells.
The treatment with Chase ABC and CS chains induced an aberrant Purkinje
cell morphogenesis in slice cultures (Fig. 4). The same treatments also
markedly decreased PTN contents in the cerebellum (Fig. 6), indicating
that most PTN is present in the CS proteoglycan-bound form in this
tissue. It is notable that the effects of CS chains were highly
dependent on the structure of CS chains. Although CS-C, -D, and -E
influenced the morphogenesis of Purkinje cells, CS-A gave no effect on
this type of cells. CS-C and -D contain ~10-20%
GlcUA(2-sulfate) 1-3GalNAc(6-sulfate) disaccharide units, and CS-E
contains 60-65% GlcUA 1-3GalNAc(4,6-disulfate) disaccharide units
(Sakai et al., 2000 ). In contrast, the contents of these oversulfated
disaccharide units are very low in CS-A, suggesting that the
oversulfated portion of CS is functionally important for the binding to
PTN. Exogenously applied PTN also induced an abnormal morphology in
Purkinje cell dendrites (Fig. 4), suggesting that normal distribution
of PTN is required for the action of PTN-PTP signaling in this phenomenon.
Although PTP is expressed by both Purkinje cells and Bergmann glia,
PTN is expressed by the latter cells in the postnatal cerebellum
(Matsumoto et al., 1994 ; Wewetzer et al., 1995 ). These expression
patterns suggest two possibilities concerning the action of PTN-PTP
signaling, although they are not mutually exclusive. One possibility is
that PTN secreted by Bergmann glia binds with PTP on the same cells
in an autocrine or paracrine manner (Fig. 9, arrow 3). The other is that
PTN secreted by Bergmann glia binds with PTP on Purkinje cells
as one of the glia-neuron interactions (Fig. 9, arrow 3').
Before binding to the transmembrane form of PTP , PTN may be pooled
by binding to the secreted form of PTP (phosphacan) in the
extracellular matrix of the ML (Figs. 6, 9, arrow 2).

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Figure 9.
A model for regulation of the morphogenesis of
Purkinje cell dendrites by PTN-PTP signaling. 1, PTN
is produced by Bergmann glia. 2, Before binding to the
transmembrane (receptor) form of PTP (rPTP ), PTN
may be pooled by binding to the secreted form of PTP
(Phosphacan) in the extracellular matrix of the ML.
3, PTN is suggested to bind with rPTP on Bergmann
glia. 3', The possibility that PTN directly binds with
rPTP on Purkinje cells cannot be excluded. 4, PTP
signaling controls the formation or maintenance, or both, of the
GLAST-positive lamellate processes of Bergmann glia, the mechanism of
which is not known at present. 4', The existence of a
GLAST-independent mechanism cannot be excluded. 5, 6,
GLAST regulates the extracellular levels of glutamate, which can induce
growth or retraction of Purkinje cell dendrites. D,
Tyrosine phosphatase domain.
|
|
Our study showed that the immunoreactivity to the glutamate transporter
GLAST on the lamellate processes of Bergmann glia was reduced in slice
cultures treated with the reagents affecting PTN-PTP signaling (Fig.
7). In contrast, the number of GFAP-positive Bergmann fibers was not
reduced under the same conditions, indicating that the decrease in
GLAST immunoreactivity was not caused by toxic effects of the reagents
on Bergmann glia. Moreover, inhibition of glutamate transporter
activity by DL-TBOA induced the aberrant morphogenesis of
Purkinje cells just as in the case of the perturbation of PTN-PTP
signaling (Fig. 8). These findings suggest that PTN-PTP signaling
acts on the Bergmann glial processes and controls the formation and
maintenance of the GLAST-positive lamellate processes of Bergmann glia,
which regulate the morphogenesis of Purkinje cell dendrites (Fig. 9).
Further studies are necessary to elucidate how PTN-PTP signaling
controls GLAST expression (Fig. 9, arrow 4). On the
other hand, we cannot exclude the possibility that PTN directly affects
Purkinje cells (Fig. 9, arrow 3').
In the developing cerebellum, glutamate is produced and released by
granule cells (Levi et al., 1991 ; Miranda-Contreras et al., 1999 ).
Studies using dissociated cell cultures have shown that glutamate
stimulates the dendritic growth of Purkinje cells (Cohen-Cory et al.,
1991 ; Hirai and Launey, 2000 ), suggesting that glutamate released in
the extracellular space by granule cells influences the
morphogenesis of Purkinje cell dendrites in vivo. However,
it is not plausible that the aberrant morphogenesis of Purkinje cells
observed in this study was caused by the abnormal development of
granule cells, because the migration and differentiation of granule
cells proceeded normally in our slice cultures even in the presence of
the reagents affecting PTN-PTP signaling (Fig. 5, Table 2).
Furthermore, although the growth of Purkinje cell dendrites was
stimulated in the dissociated coculture system of Purkinje cells and
granule cells, most of the Purkinje cells had multiple primary
dendrites extending in various directions (Baptista et al., 1994 ; Hirai
and Launey, 2000 ), suggesting that granule cells do not function in the
determination of polarity in Purkinje cells.
In this context, Bergmann glia settle in a quite important position.
The cell bodies of Bergmann glia closely associate with Purkinje cell
bodies and extend polarized shaft processes with fine lamellate
processes toward the pial surface. Of the two, the latter processes
express GLAST and closely surround both the cell bodies and dendrites
of Purkinje cells during postnatal development (Furuta et al., 1997 ;
Ullensvang et al., 1997 ; Yamada et al., 2000 ) and in adults (Rothstein
et al., 1994 ; Lehre et al., 1995 ), regulating the extracellular
glutamate levels around this type of cell (Barbour et al., 1994 ). In
the present study, we found that the GLAST immunoreactivity was reduced
around the Purkinje cells of aberrant morphology and that the
inhibition of the glutamate transporter activity induced the abnormal
morphogenesis of Purkinje cell dendrites. On the basis of these
findings, we suggest that at least one mechanism for Bergmann
glia to regulate the morphogenesis of Purkinje cell dendrites is by
modulating the extracellular glutamate levels through the
glutamate-transporting activity of GLAST (Fig. 9, arrows 5,
6).
Although the directed growth of Purkinje cell dendrites might be
regulated simply by the interaction between the leading processes of
the dendrites and the Bergmann glial processes (Yamada et al., 2000 ),
the mechanism for the morphological change from the MPD- to the
SPD-type Purkinje cells is a profound problem because both the growth
and retraction of the primary dendrites have to occur in the same cell.
Wilson and Keith (1998) found that glutamate can both facilitate and
inhibit the dendritic growth of hippocampal neurons, depending on the
exposure time to glutamate in dissociated cell cultures. Fine
regulation of the extracellular glutamate levels by GLAST on Bergmann
glial processes might produce a spatiotemporal pattern of the glutamate
levels around MPDs, and such a pattern might influence the final
selection of one primary dendrite. This mechanism may involve
voltage-dependent calcium channels activated after glutamate
stimulation, because a mutation in the gene encoding the 2 -2
voltage-dependent calcium channel accessory subunit was found to
increase the MPD-type Purkinje cells (Brodbeck et al., 2002 ). In
addition, we can propose another mechanism for Bergmann glia to
regulate Purkinje cell morphology. The Bergmann glial processes closely
surrounding Purkinje cell bodies may prevent the sprouting of new
primary dendrites and maintain the SPD-type morphology of Purkinje cells.
It was reported recently that mutant mice deficient in PTP (Shintani
et al., 1998 ; Harroch et al., 2000 ) and PTN (Amet et al., 2001 ) showed
no gross morphological abnormality, at least in adult animals. This
suggests that the morphogenesis of Purkinje cell dendrites is regulated
by multiple signaling mechanisms, including that of PTN-PTP , and
that the loss of PTN or PTP alone is compensated for by the other
molecules. For example, MK might compensate for PTN deficiency, and
PTP deficiency might be compensated for by the other proteoglycans
such as neurocan and syndecan-3, which bind with PTN (Bandtlow and
Zimmermann, 2000 ). On the other hand, Purkinje cells in the
GLAST-deficient mice were abnormal in that they were multiply
innervated by the climbing fibers even at the adult stage (Watase et
al., 1998 ). A detailed description of Purkinje cell development in
these mutant mice has not been reported, and it will be interesting to
analyze the development of the cerebellum in single- and double-mutant
mice for these genes.
 |
FOOTNOTES |
Received Aug. 16, 2002; revised Dec. 31, 2002; accepted Jan. 3, 2003.
This study was supported in part by grants-in-aid for scientific
research from Fujita Health University and from the Ministry of
Education, Science, Sports and Culture of Japan.
Correspondence should be addressed to Masahiko Tanaka, Division of Cell
Biology, Institute for Comprehensive Medical Science, Fujita Health
University, Toyoake, Aichi 470-1192, Japan. E-mail: mtanaka{at}fujita-hu.ac.jp.
 |
References |
-
Altman J,
Anderson WJ
(1972)
Experimental reorganization of the cerebellar cortex. I. Morphological effects of eliminating all microneurons with prolonged X-irradiation started at birth.
J Comp Neurol
146:355-406[Web of Science][Medline].
-
Amet LEA,
Lauri SE,
Hienola A,
Croll SD,
Lu Y,
Levorse JM,
Prabhakaran B,
Taira T,
Rauvala H,
Vogt TF
(2001)
Enhanced hippocampal long-term potentiation in mice lacking heparin-binding growth-associated molecule.
Mol Cell Neurosci
17:1014-1024[Web of Science][Medline].
-
Armengol J-A,
Sotelo C
(1991)
Early dendritic development of Purkinje cells in the rat cerebellum. A light and electron microscopic study using axonal tracing in "in vitro" slices.
Dev Brain Res
64:95-114[Medline].
-
Bandtlow CE,
Zimmermann DR
(2000)
Proteoglycans in the developing brain: new conceptual insights for old proteins.
Physiol Rev
80:1267-1290[Abstract/Free Full Text].
-
Baptista CA,
Hatten ME,
Blazeski R,
Mason CA
(1994)
Cell-cell interactions influence survival and differentiation of purified Purkinje cells in vitro.
Neuron
12:243-260[Web of Science][Medline].
-
Barbour B,
Keller BU,
Llano I,
Marty A
(1994)
Prolonged presence of glutamate during excitatory synaptic transmission to cerebellar Purkinje cells.
Neuron
12:1331-1343[Web of Science][Medline].
-
Bellocchio EE,
Hu H,
Pohorille A,
Chan J,
Pickel VM,
Edwards RH
(1998)
The localization of the brain-specific inorganic phosphate transporter suggests a specific presynaptic role in glutamatergic transmission.
J Neurosci
18:8648-8659[Abstract/Free Full Text].
-
Bernhardt RR,
Schachner M
(2000)
Chondroitin sulfates affect the formation of the segmental motor nerve in zebrafish embryo.
Dev Biol
221:206-219[Web of Science][Medline].
-
Berry M,
Bradley P
(1976)
The growth of the dendritic trees of Purkinje cells in the cerebellum of the rat.
Brain Res
112:1-35[Web of Science][Medline].
-
Berry M,
Bradley P,
Borges S
(1978)
Environmental and genetic determinants of connectivity in the central nervous system
an approach through dendritic field analysis.
Prog Brain Res
48:133-146[Medline]. -
Brittis PA,
Silver J
(1994)
Exogenous glycosaminoglycans induce complete inversion of retinal ganglion cell bodies and their axons within the retinal neuroepithelium.
Proc Natl Acad Sci USA
91:7539-7542[Abstract/Free Full Text].
-
Brodbeck J,
Davies A,
Courtney J-M,
Meir A,
Balaguero N,
Canti C,
Moss FJ,
Page KM,
Pratt WS,
Hunt SP,
Barclay J,
Rees M,
Dolphin AC
(2002)
The ducky mutation in Cacna2d2 results in altered Purkinje cell morphology and is associated with the expression of a truncated
2 -2 protein with abnormal function.
J Biol Chem
277:7684-7693[Abstract/Free Full Text]. -
Canoll PD,
Barnea G,
Levy JB,
Sap J,
Ehrlich M,
Silvennoinen O,
Schlessinger J,
Musacchio JM
(1993)
The expression of a novel receptor-type tyrosine phosphatase suggests a role in morphogenesis and plasticity of the nervous system.
Dev Brain Res
75:293-298[Medline].
-
Chung KY,
Taylor JSH,
Shum DKY,
Chan SO
(2000)
Axon routing at the optic chiasm after enzymatic removal of chondroitin sulfate in mouse embryo.
Development
127:2673-2683[Abstract].
-
Cohen-Cory S,
Dreyfus CF,
Black IB
(1991)
NGF and excitatory neurotransmitters regulate survival and morphogenesis of cultured cerebellar Purkinje cells.
J Neurosci
11:462-471[Abstract].
-
Freshney RI
(1987)
Three-dimensional culture systems.
In: Culture of animal cells: a manual of basic technique, Ed 2, pp 297-307 New York: Alan R. Liss.
-
Furuta A,
Rothstein JD,
Martin LJ
(1997)
Glutamate transporter protein subtypes are expressed differentially during rat CNS development.
J Neurosci
17:8363-8375[Abstract/Free Full Text].
-
Harroch S,
Palmeri M,
Rosenbluth J,
Custer A,
Okigaki M,
Shrager P,
Blum M,
Buxbaum JD,
Schlessinger J
(2000)
No obvious abnormality in mice deficient in receptor protein tyrosine phosphatase
.
Mol Cell Biol
20:7706-7715[Abstract/Free Full Text]. -
Hendelman WJ,
Aggerwal AS
(1980)
The Purkinje neuron: I. A Golgi study of its development in the mouse and in culture.
J Comp Neurol
193:1063-1079[Medline].
-
Hirai H,
Launey T
(2000)
The regulatory connection between the activity of granule cell NMDA receptors and dendritic differentiation of cerebellar Purkinje cells.
J Neurosci
20:5217-5224[Abstract/Free Full Text].
-
Lehre KP,
Levy LM,
Ottersen OP,
Storm-Mathisen J,
Danbolt NC
(1995)
Differential expression of two glial glutamate transporters in the rat brain: quantitative and immunocytochemical observations.
J Neurosci
15:1835-1853[Abstract].
-
Levi G,
Patrizio M,
Gallo V
(1991)
Release of endogenous and newly synthesized glutamate and of other amino acids induced by non-N-methyl-D-aspartate receptor activation in cerebellar granule cell cultures.
J Neurochem
56:199-206[Web of Science][Medline].
-
Maeda N,
Noda M
(1998)
Involvement of receptor-like protein tyrosine phosphatase
/RPTP and its ligand pleiotrophin/heparin-binding growth-associated molecule (HB-GAM) in neuronal migration.
J Cell Biol
142:203-216[Abstract/Free Full Text]. -
Maeda N,
Niinobe M,
Inoue Y,
Mikoshiba K
(1989)
Developmental expression and intracellular localization of P400 protein characteristic of Purkinje cells in the mouse cerebellum.
Dev Biol
133:67-76[Web of Science][Medline].
-
Maeda N,
Matsui F,
Oohira A
(1992)
A chondroitin sulfate proteoglycan that is developmentally regulated in the cerebellar mossy fiber system.
Dev Biol
151:564-574[Web of Science][Medline].
-
Maeda N,
Nishiwaki T,
Shintani T,
Hamanaka H,
Noda M
(1996)
6B4 proteoglycan/phosphacan, an extracellular variant of receptor-like protein-tyrosine phosphatase
/RPTP , binds pleiotrophin/heparin-binding growth-associated molecule (HB-GAM).
J Biol Chem
271:21446-21452[Abstract/Free Full Text]. -
Maeda N,
Ichihara-Tanaka K,
Kimura T,
Kadomatsu K,
Muramatsu T,
Noda M
(1999)
A receptor-like protein-tyrosine phosphatase PTP
/RPTP binds a heparin-binding growth factor midkine.
J Biol Chem
274:12474-12479[Abstract/Free Full Text]. -
Matsumoto K,
Wanaka A,
Mori T,
Taguchi A,
Ishi N,
Muramatsu H,
Muramatsu T,
Tohyama M
(1994)
Localization of pleiotrophin and midkine in the postnatal developing cerebellum.
Neurosci Lett
178:216-220[Medline].
-
Maurel P,
Rauch U,
Flad M,
Margolis RK,
Margolis RU
(1994)
Phosphacan, a chondroitin sulfate proteoglycan of brain that interacts with neurons and neural cell-adhesion molecules, is an extracellular variant of a receptor-type protein tyrosine phosphatase.
Proc Natl Acad Sci USA
91:2512-2516[Abstract/Free Full Text].
-
Miranda-Contreras L,
Benítez-Diaz PR,
Mendoza-Briceño RV,
Delgado-Saez MC,
Palacios-Prü EL
(1999)
Levels of amino acid neurotransmitters during mouse cerebellar neurogenesis and in histotypic cerebellar cultures.
Dev Neurosci
21:147-158[Medline].
-
Nishiwaki T,
Maeda N,
Noda M
(1998)
Characterization and developmental regulation of proteoglycan-type protein tyrosine phosphatase
/RPTP isoforms.
J Biochem
123:458-467[Abstract/Free Full Text]. -
Peles E,
Schlessinger J,
Grumet M
(1998)
Multi-ligand interactions with receptor-like protein tyrosine phosphatase
: implications for intercellular signaling.
Trends Biochem Sci
23:121-124[Web of Science][Medline]. -
Qi M,
Ikematsu S,
Maeda N,
Ichihara-Tanaka K,
Sakuma S,
Noda M,
Muramatsu T,
Kadomatsu K
(2001)
Haptotactic migration induced by midkine. Involvement of protein-tyrosine phosphatase
, mitogen-activated protein kinase, and phosphatidylinositol 3-kinase.
J Biol Chem
276:15868-15875[Abstract/Free Full Text]. -
Rakic P,
Sidman RL
(1973)
Organization of cerebellar cortex secondary to deficit of granule cells in weaver mutant mice.
J Comp Neurol
152:133-162[Web of Science][Medline].
-
Rothstein JD,
Martin L,
Levey AI,
Dykes-Hoberg M,
Jin L,
Wu D,
Nash N,
Kuncl RW
(1994)
Localization of neuronal and glial glutamate transporters.
Neuron
13:713-725[Web of Science][Medline].
-
Sakai T,
Kyogashima M,
Kariya Y,
Urano T,
Takada Y,
Takada A
(2000)
Importance of GlucUA
1-3GalNAc(4S, 6S) in chondroitin sulfate E for t-PA- and u-PA-mediated Glu-plasminogen activation.
Thromb Res
100:557-565[Medline]. -
Schwartz PM,
Borghesani PR,
Levy RL,
Pomeroy SL,
Segal RA
(1997)
Abnormal cerebellar development and foliation in BDNF
/ mice reveals a role for neurotrophins in CNS patterning.
Neuron
19:269-281[Web of Science][Medline]. -
Shimamoto K,
LeBrun B,
Yasuda-Kamatani Y,
Sakaitani M,
Shigeri Y,
Yumoto N,
Nakajima T
(1998)
DL-threo-
-benzyloxyaspartate, a potent blocker of excitatory amino acid transporters.
Mol Pharmacol
53:195-201[Abstract/Free Full Text]. -
Shintani T,
Watanabe E,
Maeda N,
Noda M
(1998)
Neurons as well as astrocytes express proteoglycan-type protein tyrosine phosphatase
/RPTP : analysis of mice in which the PTP /RPTP gene was replaced with the LacZ gene.
Neurosci Lett
247:135-138[Medline]. -
Snyder SE,
Li J,
Schauwecker PE,
McNeill TH,
Salton SRJ
(1996)
Comparison of RPTP
/ , phosphacan, and trkB mRNA expression in the developing and adult rat nervous system and induction of RPTP / and phosphacan mRNA following brain injury.
Mol Brain Res
40:79-96[Medline]. -
Sotelo C
(1975)
Anatomical, physiological and biochemical studies of the cerebellum from mutant mice. II. Morphological study of cerebellar cortical neurons and circuits in the weaver mouse.
Brain Res
94:19-44[Web of Science][Medline].
-
Stoppini L,
Buchs P,
Muller D
(1991)
A simple method for organotypic cultures of nervous tissue.
J Neurosci Methods
37:173-182[Web of Science][Medline].
-
Tanaka M,
Tomita A,
Yoshida S,
Yano M,
Shimizu H
(1994)
Observation of the highly organized development of granule cells in rat cerebellar organotypic cultures.
Brain Res
641:319-327[Web of Science][Medline].
-
Ullensvang K,
Lehre KP,
Storm-Mathisen J,
Danbolt NC
(1997)
Differential developmental expression of the two rat brain glutamate transporter proteins GLAST and GLT.
Eur J Neurosci
9:1646-1655[Web of Science][Medline].
-
Watase K,
Hashimoto K,
Kano M,
Yamada K,
Watanabe M,
Inoue Y,
Okuyama S,
Sakagawa T,
Ogawa S,
Kawashima N,
Hori S,
Takimoto M,
Wada K,
Tanaka K
(1998)
Motor discoordination and increased susceptibility to cerebellar injury in GLAST mutant mice.
Eur J Neurosci
10:976-988[Web of Science][Medline].
-
Wewetzer K,
Rauvala H,
Unsicker K
(1995)
Immunocytochemical localization of the heparin-binding growth-associated molecule (HB-GAM) in the developing and adult rat cerebellar cortex.
Brain Res
693:31-38[Medline].
-
Wilson MT,
Keith CH
(1998)
Glutamate modulation of dendrite outgrowth: alterations in the distribution of dendritic microtubles.
J Neurosci Res
52:599-611[Medline].
-
Yamada K,
Fukaya M,
Shibata T,
Kurihara H,
Tanaka K,
Inoue Y,
Watanabe M
(2000)
Dynamic transformation of Bergmann glial fibers proceeds in correlation with dendritic outgrowth and synapse formation of cerebellar Purkinje cells.
J Comp Neurol
418:106-120[Web of Science][Medline].
-
Yamamoto N,
Kurotani T,
Toyama K
(1989)
Neural connections between the lateral geniculate nucleus and visual cortex in vitro.
Science
245:192-194[Abstract/Free Full Text].
Copyright © 2003 Society for Neuroscience 0270-6474/03/2372804-11$05.00/0
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