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[P70]: Regulation of cortical synapse maturation by the NR2B subunit of the NMDA receptor
Author(s) -
Hall B.,
Ripley B.,
Ghosh A.
Publication year - 2006
Publication title -
international journal of developmental neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.761
H-Index - 88
eISSN - 1873-474X
pISSN - 0736-5748
DOI - 10.1016/j.ijdevneu.2006.09.132
Subject(s) - nmda receptor , neuroscience , synapse , protein subunit , synapse formation , biology , receptor , microbiology and biotechnology , biochemistry , gene
of the Cacna1f gene. In the studies reported here, we compared synaptic structure in the outer plexiform layer (OPL) of agematched mutant and control animals at postnatal days 10 and 14, the peak period for photoreceptor synaptogenesis in normal mice. Results: Transmission electron microscopy indicated that presynaptic specializations of photoreceptors (cone pedicles, rod spherules, synaptic ribbons) and synaptic contacts between photoreceptors and second-order neurons (synaptic membrane specializations, invagination of postsynaptic processes) were rare, and highly abnormal when present, in the retinas of mutant compared with age-matched control animals. Immunocytochemistry for bassoon and ribeye showed reduced expression of bassoon at P10 and P14 and the presence of ribeye in the ONL at P14. Additionally, staining for PKC and calbindin at P14 showed the extension of bipolar and horizontal-cell processes into the ONL respectively. Discussion: These observations show that normal photoreceptor synapses fail to develop, rather than first develop and subsequently degenerate, in the Cacna1f-mutant retina. Therefore, these results suggest a key role for Cav1.4 in photoreceptor synaptogenesis in the mouse retina, and potentially provide specific clues to the functional defect of the retina in some CSNB2 patients.