A STUDY OF THE PRODUCTION OF PHONATION REACTIONS IN GECKO GECKO BY STIMULATION OF THE MIDBRAIN

Abstract

Studies of the midbrain phonation and somatic motor reactions were made in acute experiments on 51 Gecko gecko.The production of the reactions of phonation by stimulation (chemical and electric stimulation) of the midbrain had been much studied in birds and mammals.But studies on reptiles for example on Gecko gecko,appeared to be yet lacking.The present paper reports observations relating to this question.The writers have paid especial attention to the reactions of phonation as well as to somatie motor and vegetative reactions.The stimulation of the midbrain (optical lobes) in Gecko gecko caused phonation reactions which are similar to that of frightened phonation of the birds and roar of mammals accompanied with first dilatation later reduction of the pupil as well as certain somatic movements and tail swings.The results of stimulation of the midbrain were essentially the same before and after the cutting off the cerebrum.The site in the midbrain where stimulation elicited reactions of phonation is in the forth lateral region to the nucleus mesencephalicus lateralis.stimulation of points beyond this region extending 0.8-1.0mm in various directions elicits no phonation reactions but somatie movements.