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Current knowledge on morphological and functional abnormalities of the thalamocortical system (TCS) in schizophrenia is incomplete and inconsistent. To study the TСS, 23 young male patients with schizophrenia and 30 healthy males were examined using structural MRI, diffusion-weighted MRI, and EEG. Structural abnormalities in the anterior and posterior thalamic radiations, multiple fronto-parietal cortical regions, and the thalamus and a decrease in α power in a subband of 11–12.5 Hz were observed in the patients with schizophrenia compared with the healthy controls. A reduced thickness of the gray matter in the medial prefrontal cortex inversely correlated with structural abnormalities of the thalamus and anterior thalamic radiation in right hemisphere. The results provide further evidence that widespread structural abnormalities of the TCS occur in early stages of schizophrenia.

The study was aimed to the analysis of correlations between anatomic brain parameters and characteristics of neurophysiological and metabolic supportive mechanisms of cognitive functions in the patients with ultra-high risk of schizophrenia. The study comprised 30 young male patients and 30 age- and sexmatched mentally healthy subjects. We used the methods of diffusion-weighted tomography, single voxel proton MR spectroscopy, and oddball ERP recording. The statistically significant intergroup differences in the structural connectivity were confirmed in the anterior thalamic radiation of the left hemisphere. The diffusion abnormalities in this area were correlated with P300 latencies and the level of γ-aminobutyric acid (GABA).

We investigated cognitive functions of attention and decision-making in 18 healthy subjects and 15 schizophrenia patients using an experimental design with consecutive presentation of two short visual stimuli (double-step). In patients with schizophrenia, an increase in the number of errors and change in the pattern of saccadic responses have been found: an increase of the number of two-saccade responses to each stimulus and a decrease in the number of single-saccade responses to the second stimulus. In schizophrenia patients, the latent period of the first of a pair of saccades has been shorter; and the latent period of single saccade has been increased in comparison with healthy subjects. Opposite lateral differences in latent periods of saccades in healthy subjects and schizophrenia patients have been found. Our results show the deficit of cognitive oculomotor control and a decrease in prognostic processes of saccade programming in schizophrenia patients.

The results of preliminary analysis at the first stage of the study have demonstrated significant relationships between electrophysiological parameters and the levels of a number of metabolites (measured by proton magnetic resonance spectroscopy) in the dorsolateral prefrontal cortex of the left cerebral hemisphere. The observed relationships are assumed to be mediated by individual-specific characteristics of activation of this cerebral region and its contribution to information processing. The neurophysiological markers of the weakened functional state of the brain are associated with decreased levels of N-acetyl aspartate and choline-containing compounds and an increased level of creatin/phosphocreatin in the tested area of the left prefrontal cortex.

We studied the influence of catechol-O-methyl transferase gene (COMT) polymorphism on the parameters of components of auditory evoked potentials (EPs) recorded under the conditions of selective attention in mentally healthy relatives of patients with endogenous psychosis. A smaller N100 latency of the EP in response to an insignificant stimulus, smaller N100 amplitude of the EP in response to a significant stimulus, smaller N200 latency, and larger P300 amplitude were found in subjects with the Met/Met genotype (with a higher dopamine activity), and a larger P200 latency was found in Val/Val genotype carriers. There was no influence of MMN gene polymorphism on the mismatch negativity.

The relationships between the parameters of waves of auditory event-related potentials (ERPs) in the oddball paradigm and the volumes of the hippocampus, amygdala, and caudate nuclei were analyzed in healthy subjects and patients with schizophrenia. The data obtained suggest that faster mental processes and stronger activation and/or synchronization of the activity of ERP wave generators in healthy subjects correspond to smaller volumes of the structures studied. The structure of the relationships in patients with schizophrenia differed from the normal one; significant correlations were observed with the volume of the caudate nuclei, and more pronounced “normalization” of neurophysiological characteristics was associated with large volumes of these structures.

The subjects were parents, siblings, and children of schizophrenic patients. Auditory evoked potentials (EPs) (P300) were recorded in the standard oddball paradigm with a probability of the target stimuli presentation of 0.2 and sound (tone) intensity of 60 dB. A comparison of these data with the results of the examination of reference groups (normal subjects free of a family history of mental pathology) showed significantly longer latent periods of N1, N2, and P3 in EPs to target stimuli in siblings and children of schizophrenic patients, as well as significantly decreased amplitudes of N1 and P2 in EPs to nontarget (standard) stimuli and longer latent periods of N2 in EPs to target stimuli in the parents of schizophrenic patients.