Selective regulation of different muscarinic receptors in septum and hippocampus neuronal cultures.
The question whether chronic membrane depolarization regulates selectively the expression of different muscarinic cholinergic receptors has been studied in primary neuronal cultures prepared from two regions of embryonic rat brain. Chronic (3 or 6 days) but not acute (3 or 24 h) membrane depolarization of cultured septal neurons with 40 mM potassium chloride have increased the number of muscarinic receptors by 168 +/- 28%, but no such effect has been observed with hippocampal cultures. Displacement experiments with the M1 selective antagonist pirenzepine have shown that muscarinic receptors in the septum of adult rat have 3-5 times lower affinity to this compound than hippocampus receptors. The results suggest that chronic membrane depolarization selectively increases the number of presynaptic muscarinic receptors, expressed by septal neurons, whereas hippocampal neurons expressing postsynaptic receptors have no such response.
Simantov
R
R
Department of Genetics, Weizmann Institute of Science, Rehovot, Israel.
Levy
R
R
D000818:Animals; D001667:Binding, Competitive; D002478:Cells, Cultured; D006624:Hippocampus / Q000166:cytology / Q000378:metabolism*; D010890:Pirenzepine / Q000378:metabolism; D011813:Quinuclidinyl Benzilate / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D011976:Receptors, Muscarinic / Q000378:metabolism*; D012686:Septal Nuclei / Q000166:cytology / Q000378:metabolism*
D011976:Receptors, Muscarinic; D010890:Pirenzepine; D011813:Quinuclidinyl Benzilate