Fluoxetine reverses REM sleep deprivation impairments and BDNF downregulation, primarily in female rats
Background
Rapid eye movement (REM) sleep deprivation (REM SD) significantly impacts mood, cognition, and synaptic plasticity, often correlating with reduced levels of neuroplasticity-related genes like brain-derived neurotrophic factor (BDNF). Current interventions for sleep-related cognitive and mood disturbances often lack sex-specific efficacy. Fluoxetine, a selective serotonin reuptake inhibitor (SSRI), is known to modulate BDNF expression, but its effects, particularly in the context of REM SD and across sexes, remain underexplored. Understanding these sex-dependent variations is crucial for developing more targeted therapeutic strategies.
Study Design
Researchers investigated the effects of 24 hours of REM SD, fluoxetine (10 mg/kg, i.p.), and their combination in male and female rats. Animals were subjected to REM SD using the modified multiple platform method. Behavioral assessments included tests for memory, immobility, rearing, pain threshold, and locomotor activity. Following behavioral testing, BDNF levels were measured in the prefrontal cortex using molecular techniques to assess neuroplasticity markers. The study design included control groups for both sexes, receiving either no intervention or vehicle administration.
Results
Following 24 hours of REM SD, animals exhibited impaired memory, increased immobility, reduced rearing, elevated pain threshold, and decreased locomotor activity. Crucially, REM SD also led to reduced BDNF levels in the prefrontal cortex. Females demonstrated partial resilience, being less sensitive to REM SD regarding pain threshold and locomotor activity compared to males. Fluoxetine administration (10 mg/kg, i.p.) showed distinct sex-specific effects:
Fluoxetine reversed the effects of
REM SDon immobility and rearing exclusively in females, while also mitigating locomotor deficits induced byREM SDin both sexes. In both sexes, fluoxetine counteractedREM SD-induced changes in pain threshold. However, fluoxetine restoredBDNFdownregulation only in females, highlighting a significant sex-dependent neuroplasticity response.
Key Findings
- 24 hours of REM SD impaired memory, increased immobility, reduced rearing, elevated pain threshold, and decreased locomotor activity in rats.
- REM SD significantly reduced
BDNFlevels in theprefrontal cortexof both male and female rats. - Female rats were less sensitive to REM SD regarding pain threshold and locomotor activity compared to males.
- Fluoxetine (10 mg/kg, i.p.) reversed immobility and rearing deficits exclusively in female rats.
- Fluoxetine restored
BDNFdownregulation only in female rats, demonstrating sex-specific neuroplasticity effects.
Why It Matters
This study underscores the critical importance of considering sex as a biological variable in both understanding sleep deprivation's impact and developing therapeutic interventions. The finding that fluoxetine's protective effects on behavior and BDNF expression are predominantly observed in females suggests that current treatment protocols for REM SD-related impairments may need sex-specific adjustments. For individuals experiencing cognitive or mood disturbances linked to sleep disruption, particularly those considering SSRIs, this research implies that efficacy could vary significantly based on sex. Future clinical translation would require human trials to confirm these sex-specific responses, potentially leading to differentiated dosing or treatment strategies for men and women suffering from sleep-related neurocognitive deficits.
fluoxetine
rem-sleep-deprivation
bdnf
sex-differences
neuroplasticity
preclinical-animal