Central serotonergic mechanisms on head twitch response induced by benzodiazepine receptor agonists.
Intraperitoneal injection of benzodiazepine receptor agonists (estazolam, zopiclone, triazolam: 0.03-0.24 mmol/kg) induces the head twitch response (HTR). The present study was undertaken to examine the possible participation of the serotonergic system in the mechanism of head twitches induced by benzodiazepine receptor agonists (BZ-RAs). The HTR induced by BZ-RAs was suppressed by pretreatment with ketanserine (1 mg/kg, i.p.), a selective 5-HT(2) receptor antagonist. Pretreatment with fluoxetine (10 mg/kg, i.p.), a 5-HT reuptake inhibitor, and 8-hydroxy-2-(di-n-propylamino)tetralin, a 5-HT(1A) receptor agonist, also suppressed the HTR induced by BZ-RAs. These results suggest that the HTR induced by BZ-RAs may be the result of an activation of postsynaptic 5-HT(2) receptors, probably due to direct action.
Tadano
T
T
Department of Pharmacology, Tohoku Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai 981-8558, Japan. tadano@tohoku-pharm.ac.jp
Hozumi
M
M
Satoh
N
N
Oka
R
R
Hishinuma
T
T
Mizugaki
M
M
Arai
Y
Y
Yasuhara
H
H
Kinemuchi
H
H
Niijima
F
F
Nakagawasai
O
O
Tan-no
K
K
Kisara
K
K
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000494:pharmacology; D000818:Animals; D014151:Anti-Anxiety Agents / Q000008:administration & dosage / Q000494:pharmacology*; D053961:Azabicyclo Compounds; D001522:Behavior, Animal / Q000187:drug effects*; D004102:Dihydroxytryptamines / Q000494:pharmacology; D004949:Estazolam / Q000008:administration & dosage / Q000494:pharmacology*; D005473:Fluoxetine / Q000494:pharmacology; D058785:GABA-A Receptor Agonists; D006993:Hypnotics and Sedatives / Q000008:administration & dosage / Q000494:pharmacology; D007650:Ketanserin / Q000494:pharmacology; D008297:Male; D051379:Mice; D010879:Piperazines / Q000008:administration & dosage / Q000494:pharmacology*; D011963:Receptors, GABA-A / Q000378:metabolism; D011985:Receptors, Serotonin / Q000378:metabolism; D012702:Serotonin Antagonists / Q000494:pharmacology; D017366:Serotonin Receptor Agonists / Q000494:pharmacology; D017367:Selective Serotonin Reuptake Inhibitors / Q000494:pharmacology; D014229:Triazolam / Q000008:administration & dosage / Q000494:pharmacology*
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D014151:Anti-Anxiety Agents; D053961:Azabicyclo Compounds; D004102:Dihydroxytryptamines; D004949:Estazolam; D005473:Fluoxetine; D058785:GABA-A Receptor Agonists; D006993:Hypnotics and Sedatives; D007650:Ketanserin; D010879:Piperazines; D011963:Receptors, GABA-A; D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists; D017367:Selective Serotonin Reuptake Inhibitors; D014229:Triazolam; C515050:zopiclone