Changes in the firing activity of serotonergic neurons in the dorsal raphe nucleus in a rat model of Parkinson's disease.
- Author:
Qiao-Jun ZHANG
1
;
Rui GAO
;
Jian LIU
;
Ya-Ping LIU
;
Shuang WANG
Author Information
1. Department of Neurology, the Second Affiliated Hospital, School of Medicine, Xioan Jiaotong University, Xioan, China. zhangqj@mail.xjtu.edu.cn
- Publication Type:Journal Article
- MeSH:
Action Potentials;
physiology;
Animals;
Disease Models, Animal;
Male;
Neurons;
physiology;
Oxidopamine;
Parkinsonian Disorders;
chemically induced;
physiopathology;
Piperazines;
pharmacology;
Pyridines;
pharmacology;
Raphe Nuclei;
physiopathology;
Rats;
Rats, Sprague-Dawley;
Serotonin;
metabolism;
Serotonin Antagonists;
pharmacology
- From:
Acta Physiologica Sinica
2007;59(2):183-189
- CountryChina
- Language:English
-
Abstract:
In the present study, changes in the neuronal activity of serotonergic neurons in the dorsal raphe nucleus (DRN) and the effect of the selective 5-HT(1A) receptor antagonist WAY-100635 in a rat model of Parkinson's disease (PD) were investigated by using extracellular single unit recording. Rat model of PD was produced by microinjection of 6-hydroxydopamine (6-OHDA) into the substantia nigra pars compacta on the right side of the brain. The results showed that the mean spontaneous firing rate of DRN serotonergic neurons in the control and 6-OHDA-lesioned rats were (1.76+/-0.11) spikes/s (n=24) and (2.43+/-0.17) spikes/s (n=21), respectively. The firing rate of serotonergic neurons in 6-OHDA-lesioned rats was significantly higher than that in the control rats (P<0.001). In the control rats, 92% (22/24) of the neurons fired regularly and 8% (2/24) fired in bursts. In rats with 6-OHDA lesions, 9% (2/21) of neurons fired regularly, 43% (9/21) exhibited irregular pattern and 48% (10/21) fired in bursts. The percentage of DRN serotonergic neurons firing in bursts was obviously higher in 6-OHDA-lesioned rats than that in the control rats (P<0.001). Local injection of WAY-100635 (3 microg in 200 nL) into the DRN significantly increased the firing rate of serotonergic neurons with no change in firing pattern in the control rats (n=19, P<0.002), but did not change the firing rate and firing pattern of serotonergic neurons in 6-OHDA-lesioned rats (n=17, P>0.05). These results suggest the dysfunction of 5-HT(1A) receptor in 6-OHDA-lesioned rats and the involvement of the DRN in the pathophysiological mechanism of PD.
