title: Characterization of the transcallosal response in aged rats and its susceptibility to nootropic drugs.
abstract: The transcallosal response in aged rats was recorded and its susceptibility to certain nootropic drugs was compared with adult animals, under urethane-anesthesia. The transcallosal response in 24-month old rats was significantly reduced in the amplitude of both positive and negative waves, as compared with 5-month old animals. In adult rats, intravenous administration of 100 mg/kg of calcium hopantenate augmented the amplitude of both the positive and the negative waves. Intraperitoneal administration of 300 mg/kg of calcium hopantenate or 10-100 mg/kg of aniracetam increased the amplitude of the negative wave by 20-30% above the control level but had no effect on the positive one. In aged rats, these drugs, given intraperitoneally, also increased the negative wave without affecting the positive one and the degree of augmentation was more prominent; both drugs increased the amplitude of the negative wave by about 190% of the control. These results suggest that the susceptibility to the nootropic drugs became even more striking in older animals, the function in the brain of which are reduced by the natural ageing process.
authors.affiliation: Research Laboratories, Yoshitomi Pharmaceutical Industries, Fukuoka, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Morio
authors.forename: T
authors.initials: T
authors.lastname: Takushiji
authors.forename: Y
authors.initials: Y
authors.lastname: Morimoto
authors.forename: T
authors.initials: T
authors.lastname: Fukuda
authors.forename: M
authors.initials: M
authors.lastname: Setoguchi
mesh_terms: D000375:Aging / Q000523:psychology*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002540:Cerebral Cortex / Q000033:anatomy & histology / Q000187:drug effects; D003337:Corpus Callosum / Q000033:anatomy & histology / Q000502:physiology*; D004558:Electric Stimulation; D004569:Electroencephalography / Q000187:drug effects; D007274:Injections, Intraperitoneal; D007275:Injections, Intravenous; D008297:Male; D010205:Pantothenic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D011619:Psychotropic Drugs / Q000494:pharmacology*; D011760:Pyrrolidinones / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D005680:gamma-Aminobutyric Acid / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: D011619:Psychotropic Drugs; D011760:Pyrrolidinones; C016030:pantogab; D010205:Pantothenic Acid; D005680:gamma-Aminobutyric Acid; C036466:aniracetam