Microglia and Astrocytes in the Lateral Vestibular Nuclei of Mice after Vestibular Stimulation

BALB/C mice were subjected to vestibular loading (rotation in individual containers at a speed of 80 rpm) for 8 h. As a result of this loading, the animals exhibited a decrease in horizontal and vertical locomotor activity, which returned to the control levels after 5 days. An immunohistochemical study of mi croglia and astrocytes in the lateral vestibular nuclei (LVN) revealed elevated levels of protein markers for astrocytes (GFAP) and microglia (Aif1) one hour and 5 days after the stimulation. These changes were indic ative of a gradual development of neuroinflammation in the LVN, which lasted for at least 5 days. Microglia, which appeared in branched shape in control animals, acquired an amoeboid reactive shape after vestibu lar loading. Moreover, expression of the genes coding for these proteins remained at the control level one hour after the stimulation and showed a reduction after 5 days. It is assumed that such a decrease helps re solve the neuroinflammation, preventing it from becoming chronic. Neuroinflammation in the acute phase is known to play a protective role and is required for plastic rearrangements of neuronal and glial networks. Transition to the chronic phase results in neuronal damage. The results of this study would allow one to de termine the period when it is reasonable to use anti-inflammatory therapy to mitigate damage. The applied model of vestibular stimulation allows one to solve problems when studying plastic rearrangements in the brain structures of the vestibular system under high-intensity sensory load.