THE SPONTANEOUS THETA-RHYTHM RECORDED FROM THE HYPOTHALAMUS POSTERIORIN THE CAT IN-VIVO

Rhythmical slow activity (theta) was mapped in the hypothalamic region in freely moving cats. We recorded well synchronized and high amplitu de theta rhythm in the medial part of the hypothalamus posterior area. The EEG recordings made from lateral part of this hypothalamic region contained only irregular activity. These findings support earlier obs ervations concerning the topography of hippocampal formation desynchro ny and synchrony system. The observations of the present study also su ggest that the hypothalamus posterior area is actively involved in the mechanisms responsible for generating theta oscillations in the cat.