SYNAPTIC PROCESSES IN PERIAQUEDUCTAL GRAY UNDER ACTIVATION OF LOCUS COERULEUS IN A ROTENONE MODEL OF PARKINSON'S DISEASE

Abstract

The aim of the study was investigation the ratio of excitatory and depressor post-stimulus manifestations of Periaqueductal gray (PAG) single neuron activity during Locus coeruleus (LC) stimulation in a Parkinson's disease (PD) model to identify excitotoxicity in neurodegeneration and the formation of persistent pain, which is poorly treatable. The electrophysiological studies were performed on 6 Albino rats (230±30g.): intact (n=3) and on the rotenone model of Parkinson's disease (PD) induced by unilateral injection of rotenone for 4 weeks holding of animals (n=3). The extracellular on-line registration of spike activity of 236 single neurons of the Periaqueductal gray (PAG) at high frequency stimulation (HFS) of Locus coeruleus (LC) in intact animals (116 neurons) and on the model of PD (120 neurons) was produced. According to programmed mathematical analyses were detected changes in depressor and excitatory responses (TD and TP), accompanied by post-tetanic depression and potentiation. In the neurons PAG at HFS LC on the model of PD the full suppression of synaptic depressor poststimulus manifestations of activity, accompanied by posttetanic and the prevalence of such excitatory has been revealed. Was the conclusion about serious neurodegenerative damage of the important antinociceptive structure - PAG, that promotes resistant chronic pain in parkinsonian patients.