Action of nootropic drugs on transcallosal responses in rats.
The effects of nootropic drugs and related compounds on transcallosal responses were examined in urethane-anesthetized rats. The transcallosal response was recorded from the surface of the anterior neocortex following electrical stimulation of the contralateral corpus callosum. The transcallosal response consisted of a biphasic positive-negative waveform. Hopantenate increased the amplitude of the positive- and negative-waves, without affecting the latency. Aniracetam, idebenone, bifemelane hydrochloride, TRH and meclofenoxate increased the amplitude of the negative-wave, without affecting the latencies. Vinpocetine and eburunamonine had no effect on the transcallosal response. Muscimol, amino-oxyacetic acid, diazepam and pentobarbital increased the amplitude of the positive-wave and decreased the amplitude of the negative-wave, without affecting the latencies. Bicuculline and picrotoxin increased the amplitude of the negative-wave, without affecting the latencies. Physostigmine decreased the amplitude of the negative-wave, without affecting the latency. Atropine was without effect. The pharmacological nature of the transcallosal response is discussed, based on findings with 16 different pharmacological agents.
Okuyama
S
S
Research Center, Taisho Pharmaceutical Co. Ltd, Saitama, Japan.
Aihara
H
H
D000818:Animals; D003337:Corpus Callosum / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005071:Evoked Potentials / Q000187:drug effects; D008297:Male; D008606:Mental Processes / Q000187:drug effects*; D010275:Parasympathetic Nervous System / Q000187:drug effects; D011619:Psychotropic Drugs / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D005680:gamma-Aminobutyric Acid / Q000502:physiology
D011619:Psychotropic Drugs; D005680:gamma-Aminobutyric Acid