Influence of motivational centers of the hypothalamus on the functioning of the visual area of cerebral cortex

Abstract

It has been demonstrated in chronic experiments on awake rabbits that a solitary stimulation of the middle hypothalamus, its ventromedial and lateral nuclei (VMN and LN), exerts a phasic effect on a formation of the primary response of the visual cortex evoked by a test light flash. In the initial period of their action, the hypothalamo-cortical responses (1-43 msec for the VMN and 1-10 msec for the LN) completely inhibit the formation of the response of the visual cortex to the light stimulus, while in the second period (43-130 msec for the VMN and 10-150 msec for the LN, respectively), selectively and highly significantly facilitate the formation of the positive phase of the primary response. In the process the negative component is suppressed, and more significantly and longer with stimulation of the VMN than of the LN (140 and 50 msec, respectively). The data obtained make it possible to hypothesize the existence of a highly organized apparatus of phasic hypothalamic (both from the VMN and the LN) control of the function of the visual cortex which is realized both by means of a facilitatory axosomatic mechanism at the level of the dendrites of the basal neurons of layer IV of the cortex and by means of a suppressant mechanism at the level of the apical dendrites of the surface layers of the cortex.

Two‐way active avoidance training‐specific increases in phosphorylated cAMP response element‐binding protein in the dorsal hippocampus, amygdala, and hypothalamus

“…The LH innervated by the Ce also innervates autonomic cell groups in the brainstem and spinal cord (Saper et al, 1976;Barbas et al, 2003), suggesting that LH may play an important role in initiating autonomic responses that accompany conditioned fear (LeDoux et al, 1988). Some other studies suggested that the VMH is involved in the motivational behaviour (Gadzhieva & Dmitrenko, 1994;Etgen & Morales, 2002). Thus, the CREB activation seen in the amygdala and hypothalamus might be critical for TWAA memory processing.…”