The changes of neuronal activity of the zone incerta in a rodent model of Parkinson's disease / 西安交通大学学报·英文版

ABSTRACT

Objective: To study the changes in neuronal activity of the zone incerta (ZI) following the unilateral lesion of the nigrostriatal pathway. Methods: Electrophysiological recordings of ZI neurons were made in normal rats and in two groups of rats at different time intervals after injection of 6-hydrodopamine (6-OHDA) into the pars compacta of substantia nigra by extracellular recording in vivo. Results: The results showed a significant increase in the mean firing rate of ZI during the second and fourth weeks after 6-OHDA lesion [n = 32, (3.6±2) Hz, Plt;0.001; n = 35, (9.3±6.6) Hz, P<0.001, respectively] compared to that of normal rats [n = 39, (9.2±5.2) Hz]. However, no significant change was observed between two groups of 6-OHDA-lesioned rats. With regard to firing pattern, 7.7% (3/39) of ZI neurons discharged regularly, 82.1% (32/39) irregularly and 10.3% (4/39) in bursts in normal rats. During the second week after 6-OHDA lesion, the regular, irregular and bursting firing neurons recorded in the ZI were 9.4% (3/32), 59.4% (19/32) and 31.3% (10/32), and during fourth week, the regular, irregular and bursting firing neurons were 14.3% (5/35) , 57.1% (20/35) and 28.6% (10/35), respectively. The firing pattern of the neurons in the three different groups did not change significantly. Conclusion: These results suggest that the firing rate of ZI neurons in 6-OHDA-lesioned rats is increased significantly, which may contribute to the pathophysiology of Parkinson's disease.