Stress can have a variety of detrimental effects on humans. From depression and anxiety to schizophrenia, stress plays a factor in the development of these diseases through neurochemical changes in the brain and elevated levels of hormones. Among the geriatric population, decreased sleep levels are known to be a frequent issue; insomnia rates among the senior population are much higher in frequency compared to any other age group. Sleep deprivation also leads to major consequences in the brain and sleep disruption is linked to neuropsychological illness; however, the specific mechanisms involved in these effects are not understood. This study focuses on the resilient effects of ΔFosB, a protein known to mediate resilience to stress and the direct effect of sleep deprivation on ΔFosB expression in areas known to mediate resilience to social stress. We hypothesize that ΔFosB may be part of the mechanism through which sleep alters resilience to social stress.

Mice were sleep-deprived for an eight-hour period for five days. After sleep deprivation they were subject to social defeat and underwent avoidance testing. The brains of these mice were removed, and immunohistochemistry analysis was conducted to determine ∆FosB expression in various sections of the brain.

The preliminary findings of this study indicates that sleep is altered in resilient animals and that sleep deprivation may lead to increased resilience to social defeat. The most significant decrease in ∆FosB expression was found in the prelimbic cortex, a change associated with resilience, and which was observed after chronic sleep deprivation. Contrarily, there was also an increase of ∆FosB expression in the nucleus accumbens.

These findings indicate that changes in ∆FosB activation in the brain is a significant factor for promoting resilient behavior in situations of social stress. In particular, a decrease in ∆FosB activation in the PLC plays a role in explaining how sleep deprivation contributes to decreased social resilience in situations of social stress.