RT Journal Article
SR Electronic
T1 Characterization of nicotinic receptors on cultured cortical neurons using anti-idiotypic antibodies and ligand binding.
JF Journal of Pharmacology and Experimental Therapeutics
JO J Pharmacol Exp Ther
FD American Society for Pharmacology and Experimental Therapeutics
SP 1216
OP 1224
VO 257
IS 3
A1 P M Lippiello
A1 K G Fernandes
A1 J J Langone
A1 R J Bjercke
YR 1991
UL http://jpet.aspetjournals.org/content/257/3/1216.abstract
AB Monoclonal anti-idiotypic antibodies that represent the internal image of nicotine's natural isomer, L-nicotine, were used in conjunction with L-[3H]nicotine binding to characterize nicotinic receptors on neurons cultured from fetal rat cortex. Of the antibodies tested, two (422F11 and 420G11) were found that recognized a class of high affinity [3H]nicotine binding sites present on neuronal cells, but not on glia. The binding properties and pharmacological specificity of these sites compared well with those determined previously for putative nicotinic cholinergic receptors in adult rat brain. The binding of [3H]nicotine to neuronal receptors was effectively inhibited by both antibodies. Receptor-bearing cells were identified using indirect immunofluorescence. Approximately 20 to 30% of the cells were labeled specifically by the anti-idiotypes. Labeling was blocked by L-nicotine and other nicotinic agonists, but not by antagonists or by alpha and neuronal bungarotoxins. The majority of cells which were labeled had either bipolar or pyramidal morphology. Fluorescent labeling was associated with cell bodies as well as with axonal and dendritic processes, consistent with the proposed roles of neuronal nicotinic receptors in neuromodulation and synaptic transmission. The results suggest that anti-idiotypic antibodies may provide a new tool suitable for studying the locations, structure and functional significance of high affinity neuronal nicotinic receptors at the cellular level.