[Effect of beta-phenylethylamine derivatives on the central nervous system. II. Pharmacological effect of the intracerebral administration of metaraminol on the central nervous system].
Six hours after intracerebral administration, the central effects of metaraminol were examined with the following results. 1) Metaraminol in doses of 40 approximately 160 mug decreased spontaneous motor activity in mice as measured by the photo-cell counters method, the wheel cage method or the open-field test. Ptosis and catalepsy induced at these doses. 2) Metaraminol in doses of 40 approximately 80 mug which influenced the spontaneous motor activity in mice, blocked the avoidance behaviour but not escape. 3) Metaraminol in doses of 1.25 approximately 10 mug which did not influence the spontaneous motor activity in mice, markedly blocked the attaching response induced by the electroshock. 4) Ten min after intraventricular administration, metaraminol in a dose of 500 mug induced the arousal pattern of EEG in sensory cortex of cats and this pattern lasted for 30 min. Ninety min after administration, EEG tracings reverted to the drowsy pattern.