慢性脑低灌注是血管性痴呆（VaD）发生的重要危险因素，海马是对缺血最敏感的脑区之一。针刺可以改善VaD大鼠认知功能障碍，恢复海马长时程增强，但其发挥上述作用的外周-中枢-海马神经环路机制尚不明确。研究表明，针刺下肢穴位的刺激信号可能依赖于坐骨神经传递至相应神经核团，继由皮层整合后激活脑内相应神经通路。孤束核是迷走神经的传入中枢；蓝斑多巴胺能神经元对海马形成广泛的纤维投射，参与认知功能的调节。前期发现，针刺足三里穴可以激活蓝斑多巴胺能神经元，改善VaD大鼠海马血流量。结合穴位的局部解剖学特征，提出假说：针刺足三里穴改善VaD大鼠认知功能的神经环路机制主要涉及坐骨神经—孤束核谷氨酸能神经元—蓝斑多巴胺能神经元—海马。本项目拟通过行为学、光声成像技术评价针刺效应，影像学明确针刺激活的神经核团，化学遗传学和病毒示踪等技术探查针刺效应体现的作用途径，揭示针刺足三里穴改善VaD认知功能的神经环路机制。

Chronic cerebral hypoperfusion is one of the most important risk factor for vascular dementia (VaD), and hippocampus is one of the most sensitive brain regions to ischemia. Previously, it has been reported that acupuncture can improve cognitive impairment caused by chronic cerebral hypoperfusion in VaD rats and restore long-term potentiation in hippocampus. However, the mechanism of peripheral-central-hippocampal nerve circuits remains unclear. Studies have shown that peripheral afferent signals of acupoints in lower limbs may depend on sciatic nerve, while brainstem nuclei mediate the peripheral afferent signals of acupuncture and then integrated by cortex to activate the related circuits. The nucleus tractus solitarius of the brain stem is the afferent center of the vagus nerve, and dopaminergic neurons in locus coeruleus form extensive fiber projections to hippocampus and participate in the regulation of cognitive function. Our previous studies have shown that acupuncture at Zusanli can activate dopaminergic neurons in locus coeruleus and improve the blood flow in the hippocampus of VaD rats. Based on these observations and local anatomical features of acupoints, the hypothesis was put forward that the mechanism of nerve circuits for improving cognitive function of VaD by acupuncture was sciatic nerve- glutamatergic neuron in nucleus tractus solitarius - dopaminergic neuron in locus coeruleus -hippocampus. By the ways of animal behavior tests and photoacoustic imaging, we evaluate the effect of acupuncture on VaD rats cognition, and confirm the brainstem nuclei by fMRI screening, as well as the effect of blockade by chemical genetics inhibition of nerve nucleus and virus tracer, it could provide the pathway of nerve nucleus and nerve circuits by acupuncture treatment in VaD.