Incongruence of Neurophysiological Manifestations as Reflection of Disturbances in Synaptic Pruning of the Cortex in Paranoid SchizophreniaAuthor(s): Arkhipov Andrei Yurevich*, Nurbekov Malik Kubanichbekovich and Strelets Valeria Borisovna
Current study provides a comprehensive analysis of neurophysiological and molecular genetic data concerning the etiology of hallucinatory-paranoid syndrome in schizophrenia. The level of cortical excitation and inhibition was determined by analysis of Event-Related Potential (ERP) parameters: latency and amplitude of intermediate (P200) and late (P300, N400) ERP components. The results showed the impossibility to determine the level of different cortical areas activation during perceiving stimuli of different significance in patients with hallucinatory-paranoid syndrome due to unidirectional shift of both ERP parameters to significant stimuli. The observed simultaneous increase of both amplitude and latency of these components in frontal regions is associated with an excessive number of aberrant synapses, and a decrease in the central regions is associated with synaptic deficit, this is due to disturbances in synaptic pruning of the cortex. Thus, the inhomogeneity of number and quality of synapses in central and frontal cortical areas was revealed, caused by inhomogeneity of their elimination process, which may be an essential condition for hallucinatory-paranoid syndrome emergence. An epigenetic analysis was also performed to assess the methylation level of gene expressing an extracellular matrix protein and playing a key role in neural connections distribution in ontogenesis. The detected epigenetic disorders in form of demethylation of RELN gene cause pathological synaptic pruning and elimination diversity in different brain areas.