title: 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.
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.
authors: INSERM U.318, Neurobiologie Préclinique, CHU-Pavillon B, BP 217, 38043, Grenoble, France.
authors: Z G
authors: ZG
authors: Ni
authors: D M
authors: DM
authors: Gao
authors: A L
authors: AL
authors: Benabid
authors: A
authors: A
authors: Benazzouz
mesh_terms: D000200:Action Potentials; D000818:Animals; D001927:Brain Diseases / Q000139:chemically induced / Q000503:physiopathology*; D003342:Corpus Striatum; D004594:Electrophysiology; D007150:Immunohistochemistry; D020646:Intralaminar Thalamic Nuclei / Q000473:pathology / Q000503:physiopathology*; D008297:Male; D009474:Neurons / Q000473:pathology / Q000502:physiology*; D016627:Oxidopamine; D051381:Rats; D017208:Rats, Wistar; D013378:Substantia Nigra
chemical_list: D016627:Oxidopamine