Natural drug extracts for a nutritive-tonic drink, promotes the induction of long-term potentiation in rat hippocampal dentate gyrus in vivo.
We have shown previously that oral administration of a nutritive-tonic drink (NTD) improves scopolamine-induced memory impairment in the passive avoidance task and Morris water-maze in mice and that this action is attributable to the natural drug extracts, rather than synthetic drugs such as taurine and caffeine, in the NTD. In order to investigate the mechanism underlying the antiamnesic effects of the natural drug extracts, the effects of the extracts on the induction of long-term potentiation (LTP) was investigated in the dentate gyrus (DG) of normal and scopolamine-treated rats. Oral administration of natural drug extracts enhanced the induction of population spike amplitude induced by weak tetanic stimulation (30 pulses at 60 Hz). Scopolamine (0.3 mg/kg, i.p.) completely inhibited the induction of LTP induced by both weak and strong tetanic stimulation (100 pulses at 100 Hz). Natural drug extracts enhanced partially but significantly the induction of LTP by strong tetanus, but had a very weak effect on that induced by weak tetanus. These results suggest that LTP induced by strong tetanus is sensitive to natural drug extracts, and that the antiamnesic effect of the NTD is at least partly attributable to the LTP-improving effect of the natural drug extracts in the DG.
Sakata
Yasuko
Y
Department of Pharmacology, College of Pharmacy, Nihon University, 7-7-1 Narashinodai, Funabashi, Chiba 274-8555, Japan.
Ishige
Kumiko
K
Ohtakara
Tomohiro
T
Ito
Yoshihisa
Y
D000284:Administration, Oral; D000818:Animals; D001628:Beverages; D000697:Central Nervous System Stimulants / Q000494:pharmacology / Q000627:therapeutic use; D018891:Dentate Gyrus / Q000187:drug effects* / Q000502:physiology; D004365:Drugs, Chinese Herbal / Q000494:pharmacology* / Q000627:therapeutic use; D017774:Long-Term Potentiation / Q000187:drug effects / Q000502:physiology*; D008297:Male; D018782:Maze Learning / Q000187:drug effects / Q000502:physiology; D008568:Memory / Q000187:drug effects* / Q000502:physiology; D008569:Memory Disorders / Q000139:chemically induced / Q000188:drug therapy / Q000503:physiopathology; D051379:Mice; D008813:Mice, Inbred ICR; D018727:Muscarinic Antagonists / Q000009:adverse effects; D009474:Neurons / Q000187:drug effects* / Q000502:physiology; D018697:Nootropic Agents / Q000494:pharmacology* / Q000627:therapeutic use; D051381:Rats; D017208:Rats, Wistar; D012601:Scopolamine / Q000009:adverse effects / Q000037:antagonists & inhibitors
D000697:Central Nervous System Stimulants; D004365:Drugs, Chinese Herbal; D018727:Muscarinic Antagonists; D018697:Nootropic Agents; D012601:Scopolamine