Pharmacological study of TA-0910, a new thyrotropin-releasing hormone (TRH) analog (IV): Effects on experimental memory impairment in mice and rats.
The effects of a new TRH analog, TA-0910, orally administered, on experimental memory impairments for the one-trial passive avoidance response in anoxic mice (light-dark box), active avoidance response in basal forebrain (BF)-lesioned rats (shuttle box), and delayed alternation task in scopolamine-treated rats (T-maze) were studied. In mice, TA-0910 (3-30 mg) administered 60 min before the retention trial dose-dependently prolonged the passive avoidance response latency reduced by CO2-exposure that was given immediately after the acquisition trial, but not when it was given 60 min before the acquisition or just after the anoxic treatment. In rats, TA-0910 (0.3-3 mg/kg) administered 40-60 min before the test trial, dose-dependently prevented the reduction in mean avoidance rate caused by BF-lesioning and elevated the scopolamine (0.1 mg/kg, i.p.)-induced reduction in percent correct choice level in the alternation task. TRH (30-300 mg/kg), on the other hand, produced no improvements in any of the above tests. These results suggest that TA-0910 improves impaired memory by correcting the retrieval process of memory.
Yamamura
M
M
Department of Pharmacology, Safety Research Laboratory, Osaka, Japan.
Kinoshita
K
K
Nakagawa
H
H
Ishida
R
R
D000284:Administration, Oral; D000647:Amnesia / Q000188:drug therapy* / Q000523:psychology; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D008297:Male; D008570:Memory, Short-Term / Q000187:drug effects; D051379:Mice; D010101:Oxygen Consumption; D051381:Rats; D011919:Rats, Inbred Strains; D012601:Scopolamine / Q000494:pharmacology; D013973:Thyrotropin-Releasing Hormone / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology
C065049:TA 0910; D013973:Thyrotropin-Releasing Hormone; D012601:Scopolamine