Changes in the Gene Expression of Inositol 1,4,5-Trisphosphate Receptors in Neurons of the Motor Cortex and Cerebellum of Rats with Experimental Hemiparkinsonism

At present, researchers are greatly interested in intracellular calcium signaling and, in particular, in the mechanisms of its disturbance in different pathologies. Nonetheless, rather limited information on the role of inositol 1,4,5-trisphosphate receptors (IP3Rs) in the development of neurodegenerative processes has been accumulated. The aim of our study was to clarify whether the IP3R1 expression in neurons under conditions of experimental Parkinson’s disease undergoes changes. In our experiments, we caused unilateral damage to dopaminergic neurons of the substantia nigra of rats using stereotaxic injections of 6-hydroxydopamine into the left ascending forebrain medial bundle (i.e., induced the state of experimental hemiparkinsonism). Using the technique of real-time polymerase chain reaction (RT PCR), we examined the level of expression of the itpr1 gene (that encodes type-1 IP3R subunits) in neurons of the cerebellum and motor cortex of intact rats and those with experimental hemiparkinsonism. In the latter animals, we observed higher levels of expression of gene itpr1 in neurons of both above-mentioned cerebral parts. In particular, the expression of this gene in the motor cortex exceeded that in the control rats more than two times, while in the cerebellum the excess was about 30 %. The higher expression of gene itpr1 in brain neurons can be a reason for abnormally intense release of Са2+ from the cellular stores during the development of neurodegenerative processes.