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[Inhibitory effect of anterior cingulate cortex on spontaneous activity of thalamic ventrobasal nucleus neurons.] [Ariticle in Chinese]

SI Wen, JIN Jing, DENG Shi-Ning, AN Shu-Ming, YIN Liang, CAO Xiao-Hua^*

Shanghai Institute of Brain Functional Genomics, the Key Laboratories of Ministry of Education of China and Science and Technology Committee of Shanghai Municipality, East China Normal University, Shanghai 200062

Abstract

The purpose of this study was to investigate the influence of electrical stimulation of anterior cingulate cortex (ACC) on spontaneous activity of neurons in thalamic ventrobasal nucleus (VB). Experiments were performed on 12 male Sprague-Dawley rats weighing 250-310 g (4-5 months old). According to Paxinos and Watson’s coordinate atlas of the rat, the frontal and parietal cortical areas were exposed by craniotomy, the recording electrodes were then inserted into the VB (P 2.4-4.1 mm, R 2.0-3.5 mm, H 5.2-6.8 mm) and the stimulating electrodes into the ACC (A 1.1-3.0 mm, R 0.0-1.0 mm, H 1.5-2.4 mm). Single-unit activities were recorded extracellularly in the VB by glass micropipettes (impedance 3-8 MΩ) filled with 0.5 mol/L sodium acetate solution containing saturated Fast Green. To study the effects of ACC activation on the spontaneous activities of VB cells, single electrical pulse (0.2 ms duration) was delivered to the ACC by a concentric bipolar stainless steel electrode (0.32 mm outer diameter). An effective ACC stimulation was determined for each VB neuron by gradually increasing the current intensity from 0.1 mA until either a significant change in the spontaneous activity of the VB neuron was observed, or the current intensity reached 0.4 mA. The results showed that ACC stimulation significantly suppressed the spontaneous activities in 12 out of 53 VB neurons (22.6%). (1) After the stimulation was delivered to ACC, the spontaneous activities of different VB neurons were totally suppressed for different time span. (2) There was obvious dose-effect relevance between ACC stimulation intensity and their inhibitory effect. The duration of complete inhibition was prolonged with the increases in the intensity and number of stimulation impulses in ACC. (3) The stimulation in the ACC depressed the spontaneous activities of VB neurons in different forms and this inhibition exhibited an accumulative effect. All these results indicate that the stimulation of ACC exerts an inhibitory influence on the spontaneous activities of VB neurons.

Key words: anterior cingulate cortex; thalamic ventrobasal nucleus; spontaneous activity

Received: 2008-05-12　　Accepted: 2009-05-05

Corresponding author: 曹晓华　　E-mail: xhcao@brain.ecnu.edu.cn

Citing This Article：

SI Wen, JIN Jing, DENG Shi-Ning, AN Shu-Ming, YIN Liang, CAO Xiao-Hua. [Inhibitory effect of anterior cingulate cortex on spontaneous activity of thalamic ventrobasal nucleus neurons.] [Ariticle in Chinese] . Acta Physiol Sin 2009; 61 (3): 279-284 (in Chinese with English abstract).