Coexpression of opsin- and VIP-like-immunoreactivity in CSF-contacting neurons of the avian brain.
Cerebrospinal fluid-contacting (CSF) cells in both the septal and the tuberal areas in the brain of the ring dove are labeled by RET-P1, a monoclonal antibody to opsin that reacts with inner and outer segment membranes of rod photoreceptors in a variety of vertebrates. Immunoblot analysis of proteins from diverse brain regions, however, revealed bands of anti-RET-P1 immunoreactivity that did not correspond to opsin. Binding of RET-P1 to opsin-containing membranes, was not inhibited by membranes rich in muscarinic and beta-adrenergic receptor proteins (red blood cells, heart, lung) taken from doves. RET-P1-immunoreactive CSF-contacting cells emit a dendritic process that penetrates the ependyma and ends in a knob-like terminal suspended in the ventricle. These cells also possess other processes that penetrate more or less deeply into the neuropil. Additionally, a band of labeled fibers occurs in the external layer of the median eminence. A double-label technique demonstrated that RET-P1-positive cells coexpress VIP-like immunoreactivity. VIP-positive cells in other brain areas are not RET-P1-positive.
Silver
R
R
Department of Psychology, Barnard College, Columbia University, New York, NY 10027.
Witkovsky
P
P
Horvath
P
P
Alones
V
V
Barnstable
C J
CJ
Lehman
M N
MN
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D001717:Birds / Q000033:anatomy & histology*; D001921:Brain / Q000166:cytology*; D003370:Coturnix; D004372:Ducks; D005136:Eye Proteins / Q000276:immunology*; D005455:Fluorescent Antibody Technique; D007031:Hypothalamus / Q000166:cytology; D007124:Immunoenzyme Techniques; D007150:Immunohistochemistry; D008297:Male; D008473:Median Eminence / Q000166:cytology; D009474:Neurons / Q000648:ultrastructure*; D017299:Rod Opsins; D014660:Vasoactive Intestinal Peptide / Q000276:immunology*
D000911:Antibodies, Monoclonal; D005136:Eye Proteins; D017299:Rod Opsins; D014660:Vasoactive Intestinal Peptide