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Unilateral lesion of the nigrostriatal pathway induces a transient decrease of firing rate with no change in the firing pattern of neurons of the parafascicular nucleus in the rat.

Z G Ni·D M Gao·A L Benabid·A Benazzouz
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Abstract

Electrophysiological recordings of thalamic parafascicular nucleus neurons were done in normal rats and in three groups of rats at different time intervals after injection of 6-hydroxydopamine into the pars compacta of substantia nigra. In normal rats, parafascicular neurons exhibited low firing rates (3.88+/-0.80 spikes/s). Concerning the pattern, 59% of the units discharged irregularly and 41% exhibited bursty pattern. In rats with 6-hydroxydopamine lesions, the firing rate decreased significantly during the first week post-lesion (1.15+/-0.36 spikes/s, P<0.01). During the second week, the firing rate was slightly, but not significantly, lower (2.59+/-0.41 spikes/s, P>0.05) than that of normal rats to return to the basal level three weeks post-lesion (3. 66+/-0.41 spikes/s, P>0.05). In these three groups of 6-hydroxydopamine-lesioned rats, the firing pattern showed no change when compared to control animals. These results show that the lesion of nigral dopaminergic neurons induced a transient decrease of the firing rate of parafascicular neurons with no change in the firing pattern demonstrating the absence of a stable influence of the dopaminergic system on the spontaneous activity of parafascicular neurons.

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Action PotentialsAnimalsBrain DiseasesCorpus StriatumElectrophysiologyImmunohistochemistryIntralaminar Thalamic NucleiMaleNeuronsOxidopamineRatsRats, WistarSubstantia NigraJournal ArticleResearch Support, Non-U.S. Gov't

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Z G Ni, D M Gao, A L Benabid, A Benazzouz. 2000. Unilateral lesion of the nigrostriatal pathway induces a transient decrease of firing rate with no change in the firing pattern of neurons of the parafascicular nucleus in the rat.. https://doi.org/10.1016/s0306-4522(00)00337-7

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