Institute of Neurobiology, Institutes of Brain Science and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200032, China.
Brain Res Bull. 2010 Apr 5;81(6):574-8. doi: 10.1016/j.brainresbull.2009.12.009. Epub 2009 Dec 28.
The medial thalamus (MT) and anterior cingulate cortex (ACC) are essential components in mediating the affective emotional-aspect of pain. Whether ACC modulates the neuron activity in MT has not been elucidated and clarifying this point will further reveal the neurobiological mechanism underlying pain related emotions. In the present study, we used in vivo single unit recording and retrograde tracing technique to demonstrate that the majority of examined neurons in the central lateral nucleus (CL), an important nucleus of MT, responded to noxious stimulation. Tetanic stimulation in the ACC increased spike activities of nociceptive-responding neurons in the CL; retrograde tracing by fluorogold in the CL showed the positive neurons are distributed bilaterally in the ACC. Taken together, we demonstrated descending modulation to nociceptive responses of CL neurons by direct projections from the ACC, which may underlie the neuronal mechanism of negative pain emotions.
中丘脑 (MT) 和前扣带皮层 (ACC) 是介导疼痛情感方面的重要组成部分。ACC 是否调节 MT 中的神经元活动尚不清楚，阐明这一点将进一步揭示疼痛相关情绪的神经生物学机制。在本研究中，我们使用活体单细胞记录和逆行追踪技术证明，在中央外侧核 (CL) 中检测到的大多数神经元对伤害性刺激有反应，CL 是 MT 的一个重要核团。ACC 中的强直刺激增加了 CL 中伤害性反应神经元的尖峰活动；CL 中的荧光金逆行追踪显示，阳性神经元在 ACC 中双侧分布。综上所述，我们证明了来自 ACC 的直接投射对 CL 神经元伤害性反应的下行调制，这可能是负性疼痛情绪的神经元机制。
