Unilateral lesion of the subthalamic nucleus transiently provokes bilateral subacute glial cell proliferation in the adult rat substantia nigra

Ablative or functional lesions of the subthalamic nucleus (STN) lead to significant improvements of motor deficits and major levodopa associated motor complications in patients with Parkinson's disease. The biological mechanisms underlying the clinical effectiveness still remain largely unknown. It has been demonstrated previously that the adult substantia nigra (SN) bears the capacity for cellular plasticity throughout adulthood and that this property can be influenced by external stimuli. In the present study we investigated the subacute and chronic effects of unilateral STN-lesion on newly generated neural cells in the adult healthy SN of the rat. With this experimental design we demonstrate a bilateral transient increase in the total numbers of newborn nigral cells following STN-lesion. Additionally, we show a transient bilateral decrease in the number of newborn neuro-glial antigen 2 (NG2)-positive and in the number of new microglia cells. No newborn neurons, however, were detected. Thus, we conclude that unilateral ablative STN lesion transiently changes plasticity of neural cell subpopulations in the healthy adult SN of the rat. (c) 2007 Elsevier Ireland Ltd. All rights reserved.