Apomorphine-induced modulation of neural activities in the ventrolateral striatum of rat

纹状体腹外侧部分（Svl）的多巴胺能系统是基底神经节的一部分，在口面部运动的调节中起重要作用：双侧多巴胺d1样受体和d2样受体的共同刺激引起大鼠的重复下颌运动。然而，Svl神经元的活动是如何通过多巴胺能受体的激活来调节的，目前尚不清楚。在本研究中，我们系统地注射非选择性多巴胺受体激动剂阿波啡（2mg /kg静脉注射），在氨基甲酸乙酯麻醉下诱导下颌运动，并从Svl神经元进行多通道单元记录。根据放电模式，Svl神经元可分为两个亚型；相性活跃（PA）和张力活跃（TA）神经元。阿波啡对大鼠上皮层PA神经元的不同作用可能反映了中棘神经元d1样受体和d2样受体的差异表达。阿帕吗啡诱导的TA神经元活动抑制与同步输出减少可能减少局部释放的乙酰胆碱，这可能调节阿帕吗啡诱导的下颌运动。

The dopaminergic system in the ventrolateral portion of striatum(Svl), a part of basal ganglia, plays an important role in the regulation of orofacial movements : bilateral co-stimulation of both dopamine D1-like and D2-like receptors elicits repetitive jaw movements in rats. However, it is still unknown how activities of Svl neurons are modulated by activation of dopaminergic receptors. In the present study, we systematically injected apomorphine(2 mg/kg i. v.), a non-selective dopamine receptor agonist, that induced jaw movements under urethane anesthesia, and performed multi-channel unit recording from Svl neurons. According to the spike firing patterns, the Svl neurons were classified into two subtypes ; phasically active(PA) and tonically active(TA) neurons. The divergent effects of apomorphine on PA neurons in the Svl might reflect differential expression of D1-like and D2-like receptors in the middle spiny neurons. Apomorphine-induced suppression of TA neuron activities with decreased synchronized outputs is likely to reduce locally released acetylcholine, which may modulate apomorphine-induced jaw movements.