Background. Establishing the relationship between the damage in the neocortex and the functional manifestations of these lesions is important to understand the mechanisms of acute seizures and their consequences. An analysis of immediate seizures in patients with a traumatic brain injury (TBI) in practice is difficult, however it can be performed in animal models. Objective. To compare the damage to functional neocortical areas with the semiology of immediate seizures and behavioral disturbances in the acute period after lateral fluid percussion (TBI model) in rats. Material and methods. The study was performed on 48 Wistar rats. TBI was modelled using lateral fluid-percussion injury to the right sensory-motor cortex. To study the semiology of immediate seizures, video recording was performed at the moment of the injury and 5 min after it. After that, a number of behavioral tests were employed. Results and conclusion. This study presents the first detailed evaluation of damage to the functional neocortical areas in the acute period of TBI using the «unfolded maps» approach. The focus of damage in the cortex increased from 3rd to 7th day and demonstrated a complex shape, extending far beyond the area of the direct impact. TBI induced immediate seizures with a variability which cannot be explained by the involvement of certain areas of the neocortex alone, as well as behavioral disturbances suggested to reflect developing necrosis predominantly in the sensory area of the neocortex.