Long term osmotic stress exposure outcomes on rat dopaminergic innervations and the associated motor behavior

Saudi J Biol Sci. 2020 Jan;27(1):210-213. doi: 10.1016/j.sjbs.2019.08.003. Epub 2019 Aug 8.

Abstract

The osmotic stress is a powerful stimulus that elicits profound peripheral and central disturbances. In the mammalian brain, osmotic stress has been associated to several glial and neuronal changes. The lack of data regarding the impact on the dopaminergic system and locomotion led us to investigate the effect of prolonged water deprivation in rat on the midbrain dopaminergic system and locomotor performance by dehydrating rats for one and two weeks. Locomotor activity and tyrosine hydroxylase (TH) expression were assessed using the open field test and immunohistochemistry respectively. Water deprivation was accompanied with a significant increment of TH expression within substantia nigra compacta (SNc) and ventral tegmental area (VTA) gradually as the duration of dehydration increases. While locomotor activity showed the inverse tendency manifested by a drop of crossed boxes number following one and two weeks of water deprivation. Our data suggest a substantial implication of midbrain dopaminergic system in the central response to the osmotic stimuli accompanied with locomotor deficiencies.

Keywords: Dopamine; Locomotion; Substantia nigra compacta; Ventral tegmental area; Water deprivation.