The selective 5-HT(1A) receptor antagonist WAY-100635 increases neuronal activity of the basolateral nucleus of the amygdala in 6-hydroxydopamine-lesioned rats.
- Author:
Qiao-Jun ZHANG
1
;
Zhong-Heng WU
;
Jian LIU
;
Tao WANG
;
Shuang WANG
;
Ling-Na HAN
Author Information
1. Department of Neurology, the Second Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an 710004, China.
- Publication Type:Journal Article
- MeSH:
Action Potentials;
Amygdala;
drug effects;
Animals;
Neurons;
drug effects;
Oxidopamine;
adverse effects;
Piperazines;
pharmacology;
Pyridines;
pharmacology;
Rats;
Receptor, Serotonin, 5-HT1A;
Serotonin 5-HT1 Receptor Antagonists;
pharmacology;
Substantia Nigra;
pathology
- From:
Acta Physiologica Sinica
2008;60(2):259-269
- CountryChina
- Language:English
-
Abstract:
In the present study, extracellular recording was used to examine the neuronal activity of the basolateral nucleus (BL) of the amygdala and the effects of systemic administration of the selective 5-HT(1A) receptor antagonist WAY-100635 on the neuronal activity in the normal rats and rats with 6-hydroxydopamine (6-OHDA)-produced lesions in the substantia nigra pars compacta (SNc). The results showed that the firing rates of BL projection neurons and interneurons were (0.39±0.04) Hz and (0.83±0.16) Hz in the normal rats, and (0.32±0.04) Hz and (0.53±0.12) Hz in 6-OHDA-lesioned rats. There was no significant difference in the firing rates of BL projection neurons and interneurons between the normal and 6-OHDA-lesioned rats. In the normal rats, all BL projection neurons fired in burst; 94% of BL interneurons fired in burst and 6% fired irregularly. In 6-OHDA-lesioned rats, 85% of BL projection neurons displayed a burst firing pattern and 15% fired irregularly; 86% of BL interneurons had a burst firing pattern and 14% fired irregularly. The distribution of firing patterns of projection neurons and interneurons in the BL in 6-OHDA-lesioned rats did not differ from that in the normal rats. Systemic administration of WAY-100635 at 0.1 mg/kg body weight did not change the mean firing rates of projection neurons and interneurons in the BL in both normal and 6-OHDA-lesioned rats. However, a higher dose of WAY-100635 at 0.5 mg/kg body weight significantly decreased the mean firing rate of BL projection neurons from (0.43±0.07) to (0.15±0.02) Hz in the normal rats (P<0.01), but significantly increased the activity of BL projection neurons in 6-OHDA-lesioned rats from (0.37±0.08) to (0.69±0.18) Hz (P<0.004). The mean firing rates of BL interneurons in the normal and 6-OHDA-lesioned rats did not change after administration of a higher dose of WAY-100635 at 0.5 mg/kg body weight. These results demonstrate that the activity of BL neurons after substantia nigra dopaminergic lesion in the SNc is regulated by activation of intrinsic and extrinsic inputs, and that 5-HT(1A) receptors significantly contribute to the regulation of the activity of BL projection neurons in both normal and 6-OHDA-lesioned rats. Furthermore, WAY-100635 induced an increase in the mean firing rate of projection neurons in the BL in 6-OHDA-lesioned rats, suggesting that 5-HT(1A) receptor is likely to play a role in generating affective symptoms in Parkinson's disease.
