Nitric oxide and cortico-striato-pallidal motor circuitry : quantitative EEG analysis of surface and depth recordings

Abstract

Rats treated with i.p. 7-NI showed a significant increase in cortical higher frequency EEG bands, associated with a corresponding and significant decrease in delta band activity. In the striatum, reduced levels of NO induced an increase in the low frequency band, and a decrease at higher frequencies. Pallidal depth recordings showed modifications to several frequency bands, similar to those found in the cortex. Although 7-NI was administered at increasing doses (from 40 to 70 mg kg–1), it was not possible to demonstrate a relationship between modified band activities and the dose of 7-NI. As suggested indirectly by the quantitative EEG data reported in this study, NO plays a fundamental role in the modulation of several neurotransmitters that are functionally involved in the cortico-striato-pallidal interactions. In fact, striatal NO seems to integrate cortical-glutamatergic and nigral-dopaminergic inputs and to modulate the efferent pathway toward the globus pallidus.