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Expression of the somatostatin subtype 2A receptor in the rabbit retina
Author(s) -
Johnson Juliette,
Wong Helen,
Walsh John H.,
Brecha Nicholas C.
Publication year - 1998
Publication title -
journal of comparative neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.855
H-Index - 209
eISSN - 1096-9861
pISSN - 0021-9967
DOI - 10.1002/(sici)1096-9861(19980330)393:1<93::aid-cne9>3.0.co;2-l
Subject(s) - retina , inner plexiform layer , colocalization , somatostatin receptor , somatostatin , axon , outer plexiform layer , biology , axon terminal , microbiology and biotechnology , neuroscience , receptor , amacrine cell , somatostatin receptor 1 , somatostatin receptor 2 , biochemistry
In the retina, somatostatin influences neuronal activity likely by acting at one or more somatostatin subtype (sst) receptors. Somatostatin and somatostatin‐binding sites are distributed predominantly to the inner retina. The present study has investigated the cellular expression of one of the sst receptors, the sst 2A receptor isoform, in the rabbit retina. These studies have used a new polyclonal antibody directed to the predicted C‐terminus of mouse sst 2A (361–369) receptor. Antibody specificity was tested by preadsorption of the primary antibody with a peptide corresponding to sst 2A (361–369). sst 2A Receptor immunoreactivity was localized mainly to the plasma membrane of rod bipolar cells and to sparsely occurring, wide‐field amacrine cells. Immunostaining in rod bipolar cells was strongest in the axon and axon terminals in lamina 5 of the inner plexiform layer (IPL) and was weakest in the cell body and dendrites. Double‐labeling experiments using a monoclonal antibody against protein kinase C (PKC; α and β), a rod bipolar cell‐selective marker, showed complete colocalization. In horizontal sections of retina, immunostained bipolar cell bodies had a dense distribution, which is in agreement with the reported distribution of rod bipolar cell bodies. Immunoreactive amacrine cell bodies were located at the border of the inner nuclear layer and the IPL, and thin varicose processes ramified mainly in laminae 2 and 4 of the IPL. These observations indicate that somatostatin influences visual information processing in the retina 1) by acting presynaptically on rod bipolar cell axon terminals and b) by influencing the activity of sparsely occurring amacrine cells. J. Comp. Neurol. 393:93–101, 1998. © 1998 Wiley‐Liss, Inc.