Coupled slow and delta oscillations between cuneothalamic and thalamocortical neurons in the chloralose anesthetized cat.

Simultaneous recordings were obtained from cuneothalamic (extracellular) and thalamocortical (intracellular) cells in chloralose anesthetized cats. It was found that cuneothalamic neurons present slow rhythmicity (0.1-1 Hz) tightly coupled to slow oscillations of thalamocortical neurons. This coupling was not due to a direct synaptic linkage but rather produced by other (s) structure (s) probably the cortex. Furthermore, the cuneothalamic neurons also showed delta rhythms (1-4 Hz) coherently oscillating with the delta rhythms of thalamocortical cells which suggests that these rhythms are more widespread than previously thought, and may be a general phenomenon characterizing quiet sleep in multiple structures.