INTRODUCTION AND AIM: Multisensory information processing in the brain (e.g. visual in the auditory cortex and auditory in the visual cortex, etc.) is an important direction of current sensory neurophysiology. Although our previous experiments have shown the implication of infraslow brain potential oscillations (ISO) in mono-modal sensory information processing in the brain, the role of ISO (frequencies <0.5 Hz) in multisensory neuroprocessing remains unknown. The aim of this study was to identify the role of ISO dynamical shifts (if any) in multisensory processing of visual, auditory and gustatory information in the primary sensory cortical areas of the brain. METHODS: Experimental procedures were done in accordance with European Parliament and Council Directive (2010/63/EU) on the protection of animals used for scientific purposes. Experiments were performed on urethane anesthetized (1mg/kg, i.p.) 30 male adult albino rats (n=720 repeated sessions) with stereotaxic electrodes implanted in primary visual (V1), auditory (A1) and gustatory (G1) cortical areas. ISO were rerecorded from V1 during animal exposure to the auditory and gustatory sensory stimuli; ISO from A1 were recorded under application of visual and gustatory stimuli; ISO from G1 were recorded during auditory and visual sensory stimulation. We analyzed ISO dynamics by means of mathematical (power spectral analysis) and statistical (one-way ANOVA) procedures. RESULTS: In V1, A1 and G1 cortical areas we found various domains of infraslow brain potentials, these were: ISO in the domain of seconds (0.1-0.5 Hz), multisecond ISO (0.0167-0.05 Hz) and ISO in the range of minutes (<0,0055 Hz). Statistically significant shifts (P<0.05) of ISO (mainly in the range of seconds) were observed: in V1 during application of auditory and gustatory stimuli, in A1 during animal exposure to visual and gustatory stimuli, and in G1 under visual and auditory sensory stimulation (e.g. modality-specific and stimulus-specific patterns of ISO arose in V1 in response to the presentation of not only visual stimuli but to auditory and gustatory, in A1 in response to the presentation of not only auditory but to visual and gustatory stimulation, in G1 in response to the presentation of not only gustatory but to visual and acoustic stimuli). In some cases we also documented implication of multisecond ISO dynamical changes in multisensory information processing, but not the ISO in the domain of minutes. CONCLUSIONS: Based on these results, we suggest that ISO in the domain of seconds and multisecond oscillations are specifically involved in multisensory processing/analysis of afferent sensory information of different modalities in primary sensory cortical areas of the brain.