COUPLED SLOW AND DELTA-OSCILLATIONS BETWEEN CUNEOTHALAMIC AND THALAMOCORTICAL NEURONS IN THE CHLORALOSE ANESTHETIZED CAT

Simultaneous recordings were obtained from cuneothalamic (extracellula r) and thalamocortical (intracellular) cells in chloralose anesthetize d cats. It was found that cuneothalamic neurons present slow rhythmici ty (0.1-1 Hz) tightly coupled to slow oscillations of thalamocortical neurons. This coupling was not due to a direct synaptic linkage but ra ther produced by other (s) structure (s) probably the cortex. Furtherm ore, the cuneothalamic neurons also showed delta rhythms (1-4 Hz) cohe rently oscillating with the delta rhythms of thalamocortical cells whi ch suggests that these rhythms are more widespread than previously tho ught, and may be a general phenomenon characterizing quiet sleep in mu ltiple structures.