Changes in EEG spindle activity induced by ibotenic acid lesions of medialis dorsalis thalamic nuclei in the cat.

The injection of an excitotoxin into medialis dorsalis thalamic nuclei (MD) elicited a short-term increase followed by a depression on EEG spindle waves in chronically implanted cats. This biphasic action provides further evidence to the hypothesis that MD plays a crucial role in transferring and inducing spindling on frontal cortex. In addition, retrograde horseradish peroxidase transport from previously lesioned MD labeled subcortical structures such as basal forebrain, anterior hypothalamus, reticular thalamic nucleus, ventral tegmental area, and locus coeruleus.