The effects of 5-HT receptor blockade on memory formation in the chick: possible interactions between beta-adrenergic, and serotonergic systems.
An antagonist, 21-009, with high affinity for 5-HT1B receptors and some for beta-adrenergic receptors, induces amnesia in the domestic chick when given centrally before training, using a one-trial passive avoidance task. Nonspecific behavioral effects, or effects upon performance at test, almost certainly do not cause the observed amnesia. The 5-HT2 antagonist ketanserin and the 5-HT3 antagonist ICS 205-930, did not have any effects when given before training at the same dose as that at which 21-009 was effective. The unusual pattern of action of 21-009 (sensitivity only at, or around the time of learning, combined with very delayed memory loss) resembles that of certain beta-antagonists, but not others. The results are discussed in terms of both direct action on 5-HT systems involved in memory formation and possible interactions between 5-HT and beta-adrenergic systems.
Sussex Centre for Neuroscience, School of Biological Sciences, University of Sussex, Brighton, UK.
R M
RM
Stephenson
R J
RJ
Andrew
D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects; D002645:Chickens; D003216:Conditioning, Operant / Q000187:drug effects; D007211:Indoles / Q000494:pharmacology; D007650:Ketanserin / Q000494:pharmacology; D008297:Male; D008568:Memory / Q000187:drug effects*; D010869:Pindolol / Q000031:analogs & derivatives / Q000494:pharmacology; D011943:Receptors, Adrenergic, beta / Q000187:drug effects / Q000502:physiology*; D011985:Receptors, Serotonin / Q000187:drug effects / Q000502:physiology*; D012702:Serotonin Antagonists / Q000494:pharmacology*; D013015:Sotalol / Q000494:pharmacology; D000077526:Tropisetron
D000319:Adrenergic beta-Antagonists; D007211:Indoles; D011943:Receptors, Adrenergic, beta; D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; C038186:4-(2-hydroxy-3-tert-butylaminopropoxy)-2-methylindole; D000077526:Tropisetron; D007650:Ketanserin; D013015:Sotalol; D010869:Pindolol