Effects of several 5-HT1A agonists on hippocampal rhythmical slow activity in unanesthetized rats.
We examined the effect of 5-hydroxytryptamine (5-HT)1A agonists on walking related, atropine-resistant, rhythmical slow activity (wr-RSA) of the hippocampus in rats. Selective 5-HT1A agonists, 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), flesinoxan, buspirone and ipsapirone significantly decreased the power value of 7-9 Hz band activity and the median frequency of wr-RSA. The order of potency was 8-OH-DPAT > flesinoxan = buspirone in power reduction. The 5-HT1A antagonists, (-)pindolol, (-)propranolol and spiperone, inhibited the effect of 8-OH-DPAT on wr-RSA. Pretreatment with parachlorophenylalanine did not abolish the effect of 8-OH-DPAT. These results indicate that 5-HT1A agonists reduce both power and median frequency values of wr-RSA through activation of post-synaptic 5-HT1A receptors in the forebrain in unanesthetized rats, in vivo.
Department of Neuropsychiatry, Nihon University School of Medicine, Tokyo, Japan.
K
K
Kasamo
K
K
Tada
N
N
Ueda
T
T
Kojima
M
M
Kogure
K
K
Ishikawa
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000494:pharmacology; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D015306:Biogenic Monoamines / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004569:Electroencephalography / Q000187:drug effects; D010134:Fenclonine / Q000494:pharmacology; D006624:Hippocampus / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D012702:Serotonin Antagonists / Q000494:pharmacology; D017366:Serotonin Receptor Agonists / Q000494:pharmacology*; D016138:Walking
D015306:Biogenic Monoamines; D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D010134:Fenclonine