Caffeine-augmented exercise as a pretreatment for locomotor and balance impairments induced by REM sleep deprivation in rats

Abstract

Sleep deprivation (SD) is a common problem that can lead to various neurological disorders. This study was carried out to examine how SD impacts locomotor performance and coordination in rats. Moreover, we aimed to investigate the potential synergistic benefits of caffeine supplementation coupled with treadmill exercise in mitigating any locomotor disorders induced by SD. Male rats were assigned to five groups: control, SD, SD + caffeine, SD + exercise, SD + caffeine + exercise. After 5 weeks of receiving caffeine supplementation (30 mg/kg) and/or treadmill exercise, the rats underwent 72 h of REM-SD, followed by behavioral tests. Subsequently, various analyses, including electrophysiology recordings, oxidative stress levels, neuroinflammation markers, apoptosis indicator, and histological changes were evaluated in the striatum and cerebellum. REM-SD significantly impaired motor and balance function, decreased neuronal activity, and increased oxidative stress, inflammatory, and apoptotic markers in the striatum and cerebellum. The study also found that REM-SD led to induce histopathological changes in these brain regions. Importantly, the administration of caffeine or regular exercise helped mitigate these adverse effects of REM-SD on motor, neuronal, molecular, and histological measures. Moreover, the combination of caffeine and exercise proved particularly effective, as it not only improved the motor and neuronal deficits, but also reduced the oxidative stress, inflammatory and apoptotic factors. The findings suggest that caffeine and exercise synergistically mitigate REM-SD-induced locomotor and neuronal deficits, particularly in locomotion and balance-related brain regions, potentially through reducing oxidative stress, inflammation, and apoptosis.

Keywords: Caffeine; Cerebellum; Exercise; Locomotion; Sleep deprivation; Striatum.

Fig. 1

Schematic representation of the experimental protocol and Time line of the experiment.

Fig. 2

Effects of caffeine, exercise, and exercise + caffeine on falling latency in sleep deprived rats. Values are expressed as the Mean ± SEM (n = 7). Statistical analyses were performed using one-way ANOVA followed by Tukey’s post hoc test. *P < 0.05 compared with the control group, ^#P < 0.05, ^###P < 0.001 compared with the SD group. Cont, control; SD, sleep deprivation; Caf, caffeine; Ex, exercise.

Fig. 3

Effects of caffeine, exercise, and exercise + caffeine on line crossings (A) and mean speed (B) in sleep deprived rats. Values are expressed as the Mean ± SEM (n = 7). Statistical analyses were performed using one-way ANOVA followed by Tukey’s post hoc test. **P < 0.01 compared with the control group, ^#P < 0.05, ^##P < 0.01, ^###P < 0.001 compared with the SD group. Cont, control; SD, sleep deprivation; Caf, caffeine; Ex, exercise.

Fig. 4

Representation of LFP recording from striatum and cerebellum in all studied groups.

Fig. 5

Effects of caffeine, exercise, and exercise + caffeine on the crude EEG power in the striatum (A) and cerebellum (B) in sleep deprived rats. Values are expressed as the Mean ± SEM (n = 6). Statistical analyses were performed using one-way ANOVA followed by Tukey’s post hoc test. **P < 0.01, ***P < 0.001 compared with the control group, ^#P < 0.05, ^##P < 0.01, ^###P < 0.001 compared with the SD group. Cont, control; SD, sleep deprivation; Caf, caffeine; Ex, exercise.

Fig. 6

Effects of caffeine, exercise, and exercise + caffeine on MDA (A, B) and SOD (C, D) in the striatum and cerebellum in sleep deprived rats. Values are expressed as the Mean ± SEM (n = 6). Statistical analyses were performed using one-way ANOVA followed by Tukey’s post hoc test. *P < 0.05, ***P < 0.001 compared with the control group, ^#P < 0.05, ^##P < 0.01, ^###P < 0.001 compared with the SD group. Cont, control; SD, sleep deprivation; Caf, caffeine; Ex, exercise.

Fig. 7

Effects of caffeine, exercise, and exercise + caffeine on TNF-α (A, B) and IL-10 (C, D) in the striatum and cerebellum in sleep deprived rats. Values are expressed as the Mean ± SEM (n = 6). Statistical analyses were performed using one-way ANOVA followed by Tukey’s post hoc test. **P < 0.01 compared with the control group, ^#P < 0.05, ^##P < 0.01 compared with the SD group. Cont, control; SD, sleep deprivation; Caf, caffeine; Ex, exercise.

Fig. 8

Effects of caffeine, exercise, and exercise + caffeine on the expression of caspase-3 in the striatum (A) and cerebellum (B) in sleep deprived rats. Values are expressed as the Mean ± SEM (n = 6). Statistical analyses were performed using one-way ANOVA followed by Tukey’s post hoc test. *P < 0.05 compared with the control group, ^#P < 0.05 compared with the SD group. Cont, control; SD, sleep deprivation; Caf, caffeine; Ex, exercise.

Fig. 9

Photomicrographs of H&E-stained sections in the striatum of rats. (A) Section in the control group, showing normal round neurons with prominent nucleus (arrow), normal glial cells (arrow head), and normal blood vessels (curved arrow). (B) Section in the SD group, showing normal neuronal structure (arrow), hypertrophied glial cells (arrow head) and dilated blood vessels (curved arrow). (C–E) Sections in the pretreatment groups (caffeine, exercise, and exercise + caffeine, respectively), showing normal neuronal structure (arrow), normal glial cells (arrow head), and normal blood vessels (curved arrow).

Fig. 10

Photomicrographs of H&E-stained sections in the cerebellum of rats. (A) Section in the control group, showing normal cerebellar structure, including normal Purkinje cells (arrow) and normal three layers: the molecular layer (ML), Purkinje cell layer (PL), and granular cell layer (GL). (B) Section in the SD group, showing a decrease in the diameter of the granular layer (double arrow) and changes in the Purkinje layer, including cytoplasmic vacuolization and nuclear pyknosis of the cells (dotted arrow), and a spongy appearance (star). (C–E) Sections in the pretreatment groups (caffeine, exercise, and exercise + caffeine, respectively), showing normal structure in the three layers and normal cells in the Purkinje layer (arrow), with some shrunken and vacuolated cells in this layer (dotted arrow).