Department of Anatomy, Marmara University School of Medicine, Istanbul, Turkey.
Department of Pharmacology and Clinic Pharmacology, Marmara University School of Medicine, Istanbul, Turkey.
Brain Connect. 2019 Nov;9(9):703-710. doi: 10.1089/brain.2019.0694.
The thalamo-cortical circuit is important in the genesis of absence epilepsy. This circuit can be influenced by connecting pathways from various parts of central nervous system. The aim of the present study is to define the dento-thalamic connections in Wistar animals and compare the results with genetic absence epilepsy rats from Strasbourg (GAERS) using the biotinylated dextran amine (BDA) tracer. We injected BDA into the dentate nucleus of 13 ( = 6 Wistar and = 7 GAERS) animals. The dento-thalamic connections in the Wistar animals were denser and were connected to a wider range of thalamic nuclei compared with GAERS. The dentate nucleus was bilaterally connected to the central (central medial [CM], paracentral [PC]), ventral (ventral medial [VM], ventral lateral [VL], and ventral posterior lateral [VPL]), and posterior (Po) thalamic nuclei in Wistar animals. The majority of these connections were dense contralaterally and scarce ipsilaterally. Contralateral connections were present with the parafascicular (PF), ventral posterior medial, ventral anterior (VA), and central lateral (CL) thalamic nuclei in Wistar animals. Whereas in GAERS, bilateral connections were observed with the VL and CM. Contralateral connections were present with the PC, VM, VA, and PF thalamic nuclei in GAERS. The CL, VPL, and Po thalamic nucleus connections were not observed in GAERS. The present study showed weak/deficit dento-thalamic connections in GAERS compared with control Wistar animals. The scarce information flow from the dentate nucleus to thalamus in GAERS may have a deficient modulatory role on the thalamus and thus may affect modulation of the thalamo-cortical circuit.
丘脑皮质回路在失神性癫痫的发生中起重要作用。该回路可受来自中枢神经系统各部位连接通路的影响。本研究旨在确定 Wistar 动物的齿状丘脑连接，并使用生物素化葡聚糖胺（BDA）示踪剂与来自斯特拉斯堡的遗传性失神性癫痫大鼠（GAERS）进行比较。我们将 BDA 注入 13 只（=6 只 Wistar 和=7 只 GAERS）动物的齿状核。与 GAERS 相比，Wistar 动物的齿状丘脑连接更密集，并且与更广泛的丘脑核相连。齿状核双侧与中央（中央内侧[CM]、旁中央[PC]）、腹侧（腹侧内侧[VM]、腹侧外侧[VL]和腹侧后外侧[VPL]）和后（Po）丘脑核相连。这些连接中的大多数在对侧是密集的，而在同侧是稀疏的。在 Wistar 动物中，与旁束核（PF）、腹后内侧、腹前（VA）和中央外侧（CL）丘脑核存在对侧连接。而在 GAERS 中，双侧连接与 VL 和 CM 观察到。在 GAERS 中，对侧连接与 PC、VM、VA 和 PF 丘脑核存在。在 GAERS 中未观察到 CL、VPL 和 Po 丘脑核的连接。本研究显示，与对照 Wistar 动物相比，GAERS 的齿状丘脑连接较弱/缺失。GAERS 中从齿状核到丘脑的信息流较少，可能对丘脑的调制作用不足，从而可能影响丘脑皮质回路的调制。
