Protective role of high-intensity exercise and lactate against sleep deprivation-induced alterations in hippocampal gene expression and spatial learning.

Sleep deprivation impairs cognitive function by disrupting hippocampal signaling pathways essential for memory formation. High-intensity interval training (HIIT) and lactate, a metabolic byproduct of exercise, have demonstrated potential benefits for brain plasticity, but their protective roles during sleep deprivation remain poorly understood. This study investigated the effects of six weeks of HIIT and lactate administration on memory-related gene expression and spatial learning in sleep-deprived rats. Forty-two male Wistar rats were divided into six groups: Control, Sleep Deprivation (SD), HIIT, HIIT + SD, Lactate, and Lactate + SD. After interventions, sleep deprivation was induced for 48 h. Spatial learning was assessed via the Morris Water Maze test, and hippocampal gene expression of PKA, LIMK, and cofilin was analyzed. The results showed no significant differences in spatial learning performance across groups; however, sleep deprivation caused significant downregulation of key genes involved in memory signaling. Both HIIT and lactate treatments effectively reversed these molecular impairments, notably increasing LIMK expression. These findings highlight the molecular protective effects of HIIT and lactate against sleep deprivation-induced cognitive dysfunction and suggest their potential as non-pharmacological strategies to preserve memory function under sleep loss conditions.