Article Figures & Data
Figures
- Fig. 1.
Immunogold labeling (10 nm gold) for delta 1/2 in the adult (a) and P21 (b,c) cerebellum. Note the abundant labeling of parallel fiber (pf) synapses and the low level or absence at climbing fiber (cf) synapses.Arrowheads indicate the postsynaptic densities/membranes (found on the heads of spines). P, Purkinje cell dendrite. Scale bar, 0.5 μm.
- Fig. 2.
Immunogold labeling for delta 1/2 at P14 (a, b), P10 (c,d), and P2 (e). Both parallel fiber (pf) and climbing fiber (cf) synapses show abundant gold labeling at P10 and P14 in contrast to that seen at P21 and in the adult.Arrowheads indicate the postsynaptic densities/membranes. P, Purkinje cell dendrite. Scale bar, 0.5 μm.
- Fig. 3.
Histograms illustrating the changes in immunogold labeling for delta 1/2 (top), GluR2/3 (middle), and GluR2 (bottom) in the postsynaptic density/membrane (PSD) of parallel fiber (PF) and climbing fiber (CF) synapses on Purkinje cells during development of the cerebellum. Note especially the large differences in the pattern of immunolabeling between delta 1/2 and GluR2/3 and GluR2 at P2–P5 and P21–adult. Lower levels of immunogold labeling forCF versus PF (delta 1/2) or forPF versus CF (GluR2/3; GluR2) were statistically significant (p < 0.01) at P10 (GluR2/3 only), at P14 (GluR2 only), and at P21 and in adults for all three antibodies. For delta 1/2, statistical significance also was found for the following: P5 CF versus P10 CF, P14CF versus either P21 or adult CF, and P14PF versus P21 PF.
- Fig. 4.
Colocalization of GABA (30 nm gold) neurotransmitter and delta 1/2 receptors (10 nm gold) at P10. Note the absence of GABA labeling in parallel fiber (pf; a, b) and climbing fiber (cf; b) terminals and the abundant labeling for GABA in Purkinje cell dendrites (P; b) and somata (P;c, d) and in pleomorphic vesicle-containing synaptic terminals (i). Delta receptor labeling is abundant in the postsynaptic density/membrane of parallel and climbing fiber synapses (arrowheads) but is absent from GABAergic synapses (arrows). Scale bar, 0.5 μm.
- Fig. 5.
Immunogold labeling for GluR2/3 in the postsynaptic density/membrane (arrowheads) of parallel fiber (pf) and climbing fiber (cf) synapses on Purkinje cells (P; dendrites in c, f; somata in d, g) during development.a, c, Adult; b,d, P21; e, f, P14;g, h, P10; i, P5; andj, P2. Note the higher labeling of climbing fiber synapses compared with that of parallel fiber synapses. Scale bar, 0.5 μm.
- Fig. 6.
Immunogold labeling for GluR2 in the postsynaptic density/membrane (arrowheads) of parallel fiber (pf) and climbing fiber (cf) synapses on Purkinje cells during development. a, Adult; b, P21;c, d, P14; and e, P2. Note the higher labeling of climbing fiber synapses compared with that of parallel fiber synapses. P, Purkinje cell dendrite. Scale bar, 0.5 μm.
- Fig. 7.
Immunogold labeling for GluR1 in the postsynaptic density/membrane (arrowheads) of parallel fiber (pf) and climbing fiber (cf) synapses on Purkinje cells during development. a, b, Adult;c, d, P10; and e, P2. Note the high level of staining at P10. Most synapses at P2 were not labeled as highly as those in the example shown. P, Purkinje cell dendrite (b) and somata (c,e). Scale bar, 0.5 μm.
- Fig. 8.
Summary histogram (top) and diagrams (bottom) of development of glutamate receptors at parallel (P10–adult) and climbing (P2–adult) fiber synapses.Histogram, Note especially the peak in immunogold labeling of the delta receptors at P10–P14 in climbing fiber synapses (CF), the peaks of the AMPA receptors at P2–P5, and the inverse patterns of peaks for parallel fiber synapses (PF) and climbing fiber synapses in adults for AMPA versus delta receptors. Diagrams, Climbing fibers (cf) innervate the Purkinje cell (Pj) body up to approximately the end of the second postnatal week. By P21, climbing fiber innervation is reduced to a single fiber per Purkinje cell. Climbing fiber synapses on Purkinje cell bodies (early postnatal ages) have many postsynaptic AMPA receptors (based on labeling for GluR2/3 and GluR2) and few delta receptors. Climbing fiber synapses on Purkinje cell dendrites (later postnatal ages to adult) have many AMPA receptors; they have many delta receptors in the second postnatal week but very few from P21 to adult. Immunogold labeling for delta receptors at parallel fiber (pf) synapses is always abundant, but less immunogold labeling is seen for AMPA receptors. Labeled terminals are illustrated diagrammatically as postsynaptic spine heads and necks, with the receptors arranged along the surface of the spine head. The number of receptors shown is based approximately on the values of mean number of gold particles per synapse in Tables 1 and 2 and in the Results; it is intended only to show the relative amounts and not to represent actual numbers. The asterisk denotes a level of less than one-half of a receptor per synapse.
Tables
- Table 1.
The comparison of distribution of delta receptor at different ages of the cerebellum
Number of synapses Average length of PSD1-a (M ± SE) Average number of gold/synapse (range) Number of gold/μm (M ± SE) 2 d CF 62 0.29 ± 0.01 0.24 (0–2) 1.0 ± 0.35 5 d CF 36 0.27 ± 0.02 0.61 (0–4) 2.60 ± 0.84 10 d PF 31 0.28 ± 0.02 5.52 (1–17) 21.23 ± 3.08 CF 46 0.33 ± 0.02 3.35 (0–9) 11.70 ± 1.57 14 d PF 40 0.29 ± 0.01 6.10 (1–12) 20.13 ± 1.23 CF 52 0.38 ± 0.02 5.40 (0–16) 15.34 ± 1.16 21 d PF 74 0.27 ± 0.01 6.76 (0–19) 25.24 ± 1.20 CF 31 0.27 ± 0.02 0.42 (0–2) 1.84 ± 0.50 Adult PF 109 0.32 ± 0.01 8.27 (1–19) 26.06 ± 0.92 CF 28 0.32 ± 0.02 0.46 (0–3) 1.53 ± 0.41 ↵F1-a PSD, Postsynaptic density measured in micrometers; number of gold/μm, number of gold particles per micrometer; M ± SE, mean ± SE; CF, climbing fiber synapse; and PF, parallel fiber synapse. The increase in number of gold/μm for CFs from P5 to P10 and the subsequent decrease from P14 to P21 were statistically significant (p < 0.01).
- Table 2.
The comparison of distribution of GluR2/3 receptor at different ages of the cerebellum
Number of synapses Average length of PSD2-a (M ± SE) Average number of gold/synapse (range) Number of gold/μm (M ± SE) 2 d CF 89 0.28 ± 0.01 2.60 (0–8) 9.05 ± 0.70 5 d CF 73 0.31 ± 0.01 1.99 (0–7) 6.69 ± 0.73 10 d PF 38 0.29 ± 0.02 0.84 (0–4) 3.05 ± 0.52 CF 54 0.34 ± 0.01 2.5 (0–7) 7.15 ± 0.66 14 d PF 29 0.31 ± 0.02 1.41 (0–5) 4.68 ± 1.05 CF 29 0.43 ± 0.02 2.45 (0–5) 5.88 ± 0.75 21 d PF 61 0.29 ± 0.01 0.74 (0–8) 2.44 ± 0.52 CF 24 0.27 ± 0.01 3.0 (0–8) 10.83 ± 1.64 Adult PF 162 0.31 ± 0.01 0.67 (0–6) 2.07 ± 0.28 CF 24 0.29 ± 0.02 2.88 (0–7) 9.81 ± 1.16 ↵F2-a PSD, Postsynaptic density measured in micrometers; number of gold/μm, number of gold particles per micrometer; M ± SE, mean ± SE; CF, climbing fiber synapse; and PF, parallel fiber synapse.
The lower number of gold/μm at PFs versus CFs at P10, P21, and adult was statistically significant (P < 0.01).
- Table 3.
The comparison of distribution of GluR2 receptor at different ages of the cerebellum
Number of synapses Average length of PSD (M ± SE) Average number of gold/synapse (range) Number of gold/μm (M ± SE) 2 d CF 67 0.28 ± 0.01 0.91 (0–3) 3.39 ± 0.46 5 d CF 64 0.34 ± 0.01 0.78 (0–4) 2.5 ± 0.42 10 d PF 41 0.25 ± 0.01 0.32 (0–2) 1.5 ± 0.43 CF 38 0.35 ± 0.02 0.95 (0–4) 2.6 ± 0.45 14 d PF 24 0.24 ± 0.01 0.25 (0–1) 1.02 ± 0.39 CF 48 0.35 ± 0.02 1.08 (0–4) 3.01 ± 0.44 21 d PF 70 0.27 ± 0.01 0.11 (0–2) 0.37 ± 0.14 CF 26 0.28 ± 0.02 1.12 (0–4) 4.43 ± 0.78 Adult PF 92 0.34 ± 0.01 0.18 (0–4) 0.53 ± 0.15 CF 23 0.30 ± 0.02 1.43 (0–4) 5.46 ± 0.86 Abbreviations listed on bottom of Table 2. The lower number of gold/μm at PFs versus CFs at P14, P21, and adult was statistically significant (p < 0.01).
