Abstract
<jats:p>In modern medicine, blast-induced traumatic brain injury (bTBI) represents a significant clinical problem, the relevance of which markedly increases under conditions of armed conflict. Even mild blast-related brain injury is often accompanied by minimal structural alterations; however, it may lead to functional impairments, particularly cognitive deficits, thereby complicating timely diagnosis and outcome prediction. The aim of the study was to investigate the effects of mild blast-induced closed traumatic brain injury on cognitive function in combination with the assessment of neuromuscular control and reflex parameters in mice. A model of mild blast-induced closed traumatic brain injury (mbcTBI) was implemented using an improved device designed to generate a blast wave of controlled intensity (207 kPa, equivalent to 30 psi). The injury was induced in 6-month-old male BALB/c mice weighing 27–30 g (n = 21), selected from an initial cohort of 50 animals based on preliminary testing results. At 3, 7, 14, 21, and 28 days, as well as 2 months post-injury, the general condition of the animals, forelimb grip strength, neurological status, and cognitive performance were dynamically evaluated. Cognitive function was assessed using the novel object recognition test with calculation of the discrimination index and novelty preference index. The novel object recognition test was conducted in an arena with opaque walls (40 × 40 × 20 cm) and consisted of three consecutive phases: habituation, familiarization, and testing. Statistical analysis of the experimental data was performed using the Friedman test followed by post hoc Wilcoxon signed-rank test with Bonferroni correction. The results demonstrated the absence of mortality, pronounced changes in general condition (body weight loss, deterioration of coat condition, decreased activity), and persistent neurological deficits in animals with experimental injury, which generally corresponds to the clinical and pathophysiological characteristics of mild traumatic brain injury. In the early post-traumatic period, a transient decrease in the discrimination index and novelty preference index was observed while exploratory activity was preserved, indicating temporary impairment of recognition processes. Forelimb grip strength significantly decreased on day 3 after injury modeling, which may reflect disturbances in the regulation of muscle tone and coordination. However, beginning from day 7, a trend toward recovery was noted, followed by normalization of the parameter. The assessed reflexes were largely preserved throughout the observation period. Isolated deviations recorded in the early post-traumatic phase were short-lived and reversible and were not accompanied by the development of persistent asymmetries. At later stages of observation, all parameters returned to baseline levels, which may reflect activation of compensatory and restorative mechanisms. Mild blast-induced closed traumatic brain injury in mice leads to cognitive impairment in the absence of persistent reflex and neuromuscular deficits. The obtained data confirm that the applied model is suitable for studying early post-traumatic cognitive changes, investigating mechanisms of neuroplasticity, and evaluating potential neuroprotective and rehabilitation strategies.</jats:p>