Abstracts

Rationale: Deep brain stimulation (DBS) is a safe and effective method for drug-resistant epilepsy. DBS has many therapeutic targets for epilepsy, including the anterior thalamic nucleus (ANT), medial thalamic nucleus (CMT), subthalamic nucleus (SNT), hippocampus, and cerebellum. Although it has been proved that ANT-DBS is a safe and effective treatment for drug-resistant epilepsy in clinically, the mechanism of ANT-DBS regulating drug-resistant epilepsy, especially the structural loop of neuromodulation, is not fully understood. Therefore, we have explored the structure of ANT-DBS nerve loop. Methods: Ten SD rats were randomly divided into two groups: the herpes simplex virus (HSV) injection group and pseudorabies virus (PRV) injection group. Microinjection was used to inject 0.5 ul HSV (1X10E11 infecting units/ml) or 0.5 ul PRV (1.4X10E11 infecting units/ml) into the ANT nucleus respectively. The animals were infected for one week, and they must be confirmed to be in a state of frequent death. Afterward, the animals were perfused and fixed, and the samples were taken. After the whole brain section (35um) and GFP immunofluorescence staining, the distribution of fluorescence signals was observed under a fluorescence microscope. Compared with brain structure atlas, the distribution of fluorescence signals was localized. Thus, the structure of nerve nuclei and brain associated with ANT can be determined. Results: HSV can be infected step by step along the direction of nerve conduction, PRV can be infected step by step against the direction of nerve conduction. Thus the ascending and descending structures of ANT nuclei can be observed. In HSV group, there were fluorescent signals in the ipsilateral nucleus accumbens (Nac) anterior, upper periventricular nuclei of the third ventricle, contralateral cortex M2/Cg, ANT, ventrolateral amygdaloid nucleus and upper third ventricle nuclei. In the PRV group, fluorescent signals were expressed in the ipsilateral injection of posterior Nac, the posterior lateral thalamic nucleus, the periventricular nucleus of the third ventricle, the dorsal medial of the amygdala nucleus, the dentate gyrus of the ventral hippocampus and the periventricular nucleus of the third ventricle. Conclusions: The technology of HSV virus tracing and PRV virus tracing is an effective nerve loop tracing method, which has played a perfect role in visualizing the structure of nerve loop. It is suggested that anterior thalamic nucleus stimulation (ANT-DBS) should have a better effect on epilepsy originating near the middle of the brain. Funding: National Key R&D Program of China 2017YFC1307500, The National Natural Science Foundation of China (Grant No. 81870935), Beijing-Tianjin-Hebei Cooperative Basic Research Program H2018206435