Synaptic protein expression by regenerating adult photoreceptors.

Publisher: Wiley-Liss Country of Publication: United States NLM ID: 0406041 Publication Model: Print Cited Medium: Print ISSN: 0021-9967 (Print) Linking ISSN: 00219967 NLM ISO Abbreviation: J Comp Neurol Subsets: MEDLINE

Publication: <2003-> : Hoboken, N.J. : Wiley-Liss
Original Publication: Philadelphia Wistar Institute of Anatomy and Biology

Ambystoma/*growth & development ; Cell Differentiation/*physiology ; Nerve Regeneration/*physiology ; Nerve Tissue Proteins/*metabolism ; Photoreceptor Cells/*metabolism ; Presynaptic Terminals/*metabolism; Age Factors ; Ambystoma/anatomy & histology ; Ambystoma/metabolism ; Animals ; Cells, Cultured ; Gene Expression Regulation, Developmental/physiology ; Immunohistochemistry ; Membrane Glycoproteins/metabolism ; Membrane Proteins/metabolism ; Nerve Tissue Proteins/ultrastructure ; Neurites/metabolism ; Neurites/ultrastructure ; Photoreceptor Cells/cytology ; Presynaptic Terminals/ultrastructure ; Pseudopodia/metabolism ; Pseudopodia/ultrastructure ; R-SNARE Proteins ; Synapsins/metabolism ; Synaptic Vesicles/metabolism ; Synaptic Vesicles/ultrastructure ; Synaptophysin/metabolism ; Synaptosomal-Associated Protein 25 ; Time Factors

Regeneration of functionally normal synapses is required for functional recovery after degenerative central nervous system insults and requires proper expression and targeting of presynaptic proteins by regenerating neurons. The reconstitution of presynaptic terminals by regenerating adult neurons is poorly understood, however. We examined the intrinsic ability of regenerating adult retinal photoreceptors to reconstitute properly differentiated presynaptic terminals in the absence of target contact. The expression and localization of vesicle-associated membrane protein (VAMP), synaptic vesicle protein 2 (SV2), synaptophysin, synapsin I, and synaptosomal-associated protein of 25 kDa (SNAP-25) was assessed immunocytochemically. Photoreceptor terminals in the intact retina contain VAMP, SV2, synaptophysin, and SNAP-25, but not synapsin I. Isolated, regenerating adult photoreceptors intrinsically expressed the proper complement of synaptic vesicle proteins in the absence of target contact: VAMP, SV2, and synaptophysin were present at all stages of regenerative growth; synapsin I was never expressed. At early stages of regenerative growth, VAMP, SV2, and synaptophysin were diffusely localized in the cell, with prominent VAMP labeling distributed along the plasma membrane. SV2 and synaptophysin rapidly localized to regenerated terminals, but VAMP accumulated much more slowly, indicating that these proteins are trafficked independently. In contrast, labeling for SNAP-25, which is associated with the presynaptic plasma membrane, was undetectable in regenerating photoreceptors, suggesting that SNAP-25 expression is target-regulated. Thus, regenerating photoreceptors can intrinsically regulate the expression of the proper set of synaptic vesicle proteins. Proper expression of other presynaptic proteins, such as SNAP-25, and proper subcellular localization of synaptic proteins such as VAMP, however, may require extrinsic cues such as target contact.
(Copyright 2002 Wiley-Liss, Inc.)

DA10738 United States DA NIDA NIH HHS

0 (Membrane Glycoproteins)
0 (Membrane Proteins)
0 (Nerve Tissue Proteins)
0 (R-SNARE Proteins)
0 (Synapsins)
0 (Synaptophysin)
0 (Synaptosomal-Associated Protein 25)

Date Created: 20020125 Date Completed: 20020307 Latest Revision: 20190906

20240104

10.1002/cne.10116

11807837