Facts and reflections on thalamocortical reverberation of impulses.
Experiments on cats, either unanesthetized or anesthetized with various doses of pentobarbital, showed that the cortical rhythmic after-discharge ("slow after-activity"), which has been regarded as a manifestation of reverberation of impulses in thalamocortical circuits [17], consists of a burst of spontaneous "spindles" evoked by stimulation. This conclusion is supported by the following facts: Spontaneous "spindles" and the rhythmic after-discharge respond absolutely identically (disappear) to activation of the EEG and deepening of pentobarbital anesthesia. The absence of thalamocortical reverberation is also indicated by the preservation of a rhythmic after-discharge (to clicks), synchronous with the cortex, in the thalamic relay nucleus (the medial geniculate body) after cooling or after removal of its projection zone.
D000818:Animals; D001303:Auditory Cortex / Q000502:physiology*; D001306:Auditory Pathways / Q000502:physiology*; D002415:Cats; D005071:Evoked Potentials; D005829:Geniculate Bodies / Q000502:physiology; D009433:Neural Inhibition; D009435:Synaptic Transmission; D013787:Thalamic Nuclei / Q000502:physiology*