Inhibitory effects of beta-phenylethylamine on photic-evoked potentials in the visual cortex of the cat.
We investigated the effects of beta-phenylethylamine (PEA) on photic-evoked potentials recorded from the cerebral cortex (visual cortex) in the anesthetized cat. The photic-evoked potential consisted of negative (N) and positive (P) components in the cerebral cortex, with peak times of 39.4 +/- 15.4 msec and 57.5 +/- 16.3 msec, respectively. Intravenous administration of PEA (6.5, 12.5 and 25 mg/kg) induced a dose-dependent decrease in the amplitude of the N component of photic-evoked potentials. PEA-induced decreases in the amplitude of photic-evoked potentials (at 12.5 mg/kg) were antagonized by yohimbine (2 mg/kg). Prazocin (2 mg/kg, i.v.) and propranolol (0.5 mg/kg, i.v.) did not change the PEA-induced decrease of photic-evoked potentials. Methysergide (2 mg/kg, i.v.), haloperidol (1 mg/kg, i.v.) and naloxone (0.5 mg/kg, i.v.) also failed to alter the inhibitory effect of PEA. Pretreatment with alpha-methyl-p-tyrosine or reserpine did not completely attenuate the PEA-induced decrease of photic-evoked potentials. According to these results, PEA inhibits the photic-evoked potentials in the visual cortex partially through the noradrenergic alpha 2-receptor.
Taguchi
K
K
Department of Pharmacology, Showa College of Pharmaceutical Sciences, Tokyo, Japan.
Hagiwara
Y
Y
Suzuki
Y
Y
D000758:Anesthesia; D000818:Animals; D002415:Cats; D005074:Evoked Potentials, Visual / Q000187:drug effects*; D005260:Female; D008297:Male; D008781:Methyltyrosines / Q000494:pharmacology; D010627:Phenethylamines / Q000494:pharmacology*; D010775:Photic Stimulation; D011619:Psychotropic Drugs / Q000494:pharmacology*; D012110:Reserpine / Q000494:pharmacology; D014793:Visual Cortex / Q000187:drug effects* / Q000502:physiology; D019805:alpha-Methyltyrosine
D008781:Methyltyrosines; D010627:Phenethylamines; D011619:Psychotropic Drugs; C029261:phenethylamine; D019805:alpha-Methyltyrosine; D012110:Reserpine