Transcriptome-wide changes in the Substantia Nigra following Deep Brain Stimulation in the Subthalamic Nuecleus of a PD rat model.

In this study we identify the gene espression changes that occur in the substantia nigra in a Parkinson's Disease (PD) rat model with and without deep brain stimulation (DBS). A rat model of PD was created as previously described by stereotacticaly injecting an AAV-expressing the human A53T_mutated form of a-Synuclein into the Substantia Nigra of adult rats, while control rats were injected with empty vector (EV). These mice exhibit neurodegeneration in the Substantia Nigra and Parkinson-like behaviour phenotypes. Sixteen weeks after the injection, RNA was isolated from the Substantia Nigra and Striatum. Single-end 75nt high throughput sequencing were performed on libraries prepared from the RNA. We identified over 200 genes that were differentially expressed between control and Parkinson's ratswith a log2 fold-change > |0.6|. These genes were enriched for terms related to immune activation. The genes associated with these GO terms tended to be up-regulated in the Parkinson's rats suggesting that brain-localized immune cells are more activated in Parkinson's disease. Interestingly in the rats treated with DBS, these immune-related genes were comparable to control animals. Overall design: Every sample represents RNA isolated from the ipsilateral SN of one animal six weeks after injection of either control virus (EV) or haSyn virus (haSyn). Three weeks after viral injection all animals were implanted with an electrode in the subthalamic nucleus however only (DBS) animals received high frequency stimulation. No DBS animals were not stimulated.