Electrophysiological study of the functional connections of the hypothalamus with the forebrain in the tortoise Emys orbicularis

During stimulation of the posterior hypothalamus, the evoked potentials with short latent periods, high amplitude and poor exhaustion by rhythmic stimulation were recorded in the hippocampal cortex. In the piriform cortex, the evoked potentials exhibited longer latent periods and complex configuration. Less readily the evoked potentials appeared in the neocortex, their latency being very large. During stimulation of the anterior hypothalamus, maximum activity was also localized in the hippocampal cortex. The data obtained indicate close connection between hypothalamic structures and the hippocampal cortex. The latter is presumably the main projectional area for the ascending afferentation from the hypothalamus.