FOOD MOTOR CONDITIONED REFLEX AND ELECTRICAL STIMULATION OF THE BRAIN STEM RETICULAR FORMATIONS

抄録

The effect of central stimulation of the reticular formations at low intensity which does not induce overt somatic movement has been studied in relation to the food motor conditioned reflex, using the Skinner box for rats. Stimulation of the mesencephalic reticular formation induced the previously elaborated conditioned reflex without introduction of the conditioned stimulus. The neural mechanism of this phenomenon has not been explained satisfactorily as yet, but it is suggested that it may be due to disinhibition.
In the present experiment, furthermore, it was ascertained that stimulation of the reticular formations at low intensity possesses the character of conditioned stimulus by coupling with food, in either a positive or negative signal for food conditioned reflex, i. e., possibility of changing the signal meaning in the Pavlovian concept.Electrical stimulation which indicated a positive signal in the experimental box resulted in giving rise to a striking movement in the feeding cage, notwithstanding the fact that before coupling no change of behavior had been observed with the same intensity of stimulation. Therefore, it is suggested that the current view of neurophysiology of brain stem reticular formations which is regarded exclusively as the functioning of a diffuse non-specific activating system may be revised to certain extent.