Effect of stimulation of β adrenoreceptors on conditioned reflex-related spike activity of neurons of the cat somatosensory cortex

Abstract

Using extracellular recording of impulse activity of pyramidal neurons of the cat somatosensory cortex generated in the course of realization of an operant conditioned reflex, we examined effects of microiontophoretic applications of an agonist of β2 adrenoreceptors, metaproterenol, and of an antagonist of β adrenoreceptors, propranolol, on the frequency of this impulsation. Applications of propranolol induced intensification of both background and reflex-related spiking. The effect of metaproterenol was manifested as moderate intensification of background discharges, a noticeable increase in the frequency of evoked impulsation, and an increase in the latency of impulse reactions. It is supposed that noradrenergic projections to the neocortex intensify neuronal activity via activation of β2 adrenoreceptors and suppress this activity via influencing mostly β1 adrenoreceptors. Such effects of synaptically active agents should probably be taken into account in the treatment of neurological diseases, namely epilepsy, neurodegenerative disorders, psychoemotional shifts, etc., which are accompanied by emotional and cognitive disorders.