 |
Previous Article | Next Article 
The Journal of Neuroscience, November 15, 2000, 20(22):8629-8636
A Series of Biotinylated Tracers Distinguishes Three Types of Gap
Junction in Retina
Stephen L.
Mills and
Stephen C.
Massey
Department of Ophthalmology and Visual Science, University of Texas
at Houston, Health Science Center, Houston, Texas 77030
Gap junctions serve many important roles in various tissues, but
their abundance and diversity in neurons is only beginning to be
understood. The tracer Neurobiotin has revealed many different networks
interconnected by gap junctions in retina. We compared the relative
permeabilities of five different retinal gap junctions by measuring
their permeabilities to a series of structurally related tracers. When
large tracers were injected, the staining of coupled cells fell off
more rapidly in some networks than others relative to Neurobiotin
controls. Three distinctly different permeability profiles were found,
suggesting that multiple neuronal connexin types were present. The most
permeant to large molecules were gap junctions from A-type horizontal
cells. The permeability of gap junctions of two types of amacrine cell
were not distinguishable from those from B-type horizontal cells. The
lowest permeability was found for gap junctions between cone bipolar
cells and the AII amacrine cells to which they are coupled. Because
only a single neural connexin type has been identified in retina, our
results suggest more types remain to be found.
To determine whether the unitary permeability of channels is altered by
channel modulators, we reduced permeability with octanol and a cAMP
analog. Although net permeability was substantially diminished, the
proportion by which it declined was constant across tracer size. This
suggests that these agents act only to close channels rather than alter
individual channel permeabilities. This tracer series can therefore be
used to contrast permeability properties of gap junctions in intact
circuits, even at the level of individual channels.
Key words:
gap junction; connexin; tracer coupling; retina; Neurobiotin; metabolic coupling
Copyright © 2000 Society for Neuroscience 0270-6474/00/20228629-08$05.00/0
This article has been cited by other articles:

|
 |

|
 |
 
J. J. O'Brien, W. Li, F. Pan, J. Keung, J. O'Brien, and S. C. Massey
Coupling between A-Type Horizontal Cells Is Mediated by Connexin 50 Gap Junctions in the Rabbit Retina.
J. Neurosci.,
November 8, 2006;
26(45):
11624 - 11636.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
H. Hoshi, J. O'Brien, and S. L. Mills
A Novel Fluorescent Tracer for Visualizing Coupled Cells in Neural Circuits of Living Tissue
J. Histochem. Cytochem.,
October 1, 2006;
54(10):
1169 - 1176.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
Y. Han and S. C. Massey
Electrical synapses in retinal ON cone bipolar cells: Subtype-specific expression of connexins
PNAS,
September 13, 2005;
102(37):
13313 - 13318.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
B. Lin, T. C. Jakobs, and R. H. Masland
Different Functional Types of Bipolar Cells Use Different Gap-Junctional Proteins
J. Neurosci.,
July 13, 2005;
25(28):
6696 - 6701.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
S. He, W. Dong, Q. Deng, S. Weng, and W. Sun
Seeing More Clearly: Recent Advances in Understanding Retinal Circuitry
Science,
October 17, 2003;
302(5644):
408 - 411.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
K. Djupsund, T. Furukawa, S. Yasui, and M. Yamada
Asymmetric Temporal Properties in the Receptive Field of Retinal Transient Amacrine Cells
J. Gen. Physiol.,
September 29, 2003;
122(4):
445 - 458.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
A. Devor and Y. Yarom
Electrotonic Coupling in the Inferior Olivary Nucleus Revealed by Simultaneous Double Patch Recordings
J Neurophysiol,
June 1, 2002;
87(6):
3048 - 3058.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
J. H. Singer, R. R. Mirotznik, and M. B. Feller
Potentiation of L-Type Calcium Channels Reveals Nonsynaptic Mechanisms that Correlate Spontaneous Activity in the Developing Mammalian Retina
J. Neurosci.,
November 1, 2001;
21(21):
8514 - 8522.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
K. K. Ghosh, S. Haverkamp, and H. Wassle
Glutamate Receptors in the Rod Pathway of the Mammalian Retina
J. Neurosci.,
November 1, 2001;
21(21):
8636 - 8647.
[Abstract]
[Full Text]
[PDF]
|
 |
|
|

|