Second messengers of octopamine receptors in the snail Lymnaea.
We describe octopamine responses of 3 large buccal neurons of Lymnaea and test the hypothesis that these are cAMP-dependent. The B1 neuron is excited by octopamine and the depolarisation is significantly enlarged (P < 0.05) by application of the blocker of cAMP breakdown, 3-isobutyl-1-methylxanthine (IBMX). The B1 neuron is also depolarised by forskolin, an activator of adenylyl cyclase. The B2 and B3 neurons are inhibited by octopamine, and the response is not affected by IBMX. Both cells are excited by forskolin. We conclude that the B1 neuron response to octopamine is likely to be mediated by cAMP, while the B2 and B3 responses are cAMP-independent.
Department of Biology, University of York, PO Box 373, York YO10 5YW, UK.
Samantha
S
Pitt
Agnes
A
Vehovszky
Henriette
H
Szabó
C J H
CJ
Elliott
D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D000067956:Adenylyl Cyclase Inhibitors; D000818:Animals; D002490:Central Nervous System / Q000187:drug effects; D005576:Colforsin / Q000378:metabolism / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism; D008195:Lymnaea; D009046:Motor Neurons / Q000502:physiology; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D017982:Receptors, Biogenic Amine / Q000378:metabolism*; D015290:Second Messenger Systems; D015398:Signal Transduction; D013997:Time Factors
D000067956:Adenylyl Cyclase Inhibitors; D010726:Phosphodiesterase Inhibitors; D017982:Receptors, Biogenic Amine; C027604:norsynephrine receptor; D005576:Colforsin; D000242:Cyclic AMP; D015056:1-Methyl-3-isobutylxanthine