[Evoked responses and impulse activity of the neocortex during the startle response following stimulation of the midbrain reticular formation].

The stimulation of the mid-brain reticular formation (RF) by single electrical stimuli caused a reticulo-cortical response (RCR) with 2.5--3 msec latency, composed of early (negative-positive complex) and late components. An interconnection is shown between the neuronal response and the formation of different phases of the surface RCR. The neurones of the upper cortical level took part in the response mainly during the development of the negative RCR phases. The appearance of the early positive potential was accompanied by an increase in the frequency of the background activity in the cells of the lower cortical layers. The neurones with initial inhibitory response to the RF stimulation changed their activity in the period of the early RCR components: a considerable part of neurones in the lower layers reduced their spike activity during the development of the short-latency negative oscillation.