[Responses of pyramidal tract neurons and cortico-rubral neurons to stimulation of different lateral hypothalamic structures in the cat].

Extracellular responses of pyramidal tract, corticorubral and nonidentified neurons of pericruciate cortex to electrical stimulation of lateral hypothalamus and cutaneous stimulation of all limbs were studied in cats anaesthetized with chloraloze. Responses to hypothalamic stimulation were found in 73%, 55% and 79% of cells respectively. A number of pyramidal tract neurons and nonidentified cells responded to hypothalamic stimulation monosynaptically. On the other hand the latency of corticorubral neuronal responses were longer, less stable and were considered to be polysynaptic. Some cortical neurons responded to stimulation of more than one part of the hypothalamus. Pyramidal tract and cortico-rubral neurons with axon collaterals directed to hypothalamus were identified. Some nonidentified neurons responded to hypothalamic stimulation antidromically and were considered to be corticohypothalamic neurons. It was shown that most of cortical neurons sensitive to hypothalamic stimulation responded also to cutaneous stimulation of more than one limb and had wide bilateral receptive fields.