A Bump on the Head or Late to Bed: Behavioral and Pathophysiological Effects of Sleep Deprivation after Repetitive Mild Traumatic Brain Injury in Adolescent Rats

Abstract

An old wives' tale, and strongly held dogma, maintains that one should be kept awake after a mild traumatic brain injury (mTBI) to prevent a coma. This, however, conflicts with the known benefits of sleep: repair and restoration. We therefore sought to examine the effects of sleep deprivation (SD) in the post-traumatic sleep period on post-concussion symptomology (PCS). Adolescent male and female rats were administered repetitive mTBIs (RmTBI) or sham injuries and were then assigned to 5 h of SD or left undisturbed. All animals were then tested using seven behavioral tasks validated to examine PCS, followed by analysis of serum cytokines, and quantitative real-time PCR for messenger RNA (mRNA) expression. Exposure to 3 SD epochs significantly impaired behavior in 4 of 7 of the measures, while RmTBI also produced dysfunction in 5 of 7 tests, but the effects of SD and RmTBI were not cumulative. SD induced long-lasting changes in serum levels of Tnf-α, IL6, and IL-1ß. mRNA expression in the pre-frontal cortex, hippocampus, hypothalamus, and anterior cingulate cortex was modified in response to SD and RmTBI; but similar to the behavioral measures, the mRNA changes were not cumulative. Consequently, we report that SD often produced impairments similar or worse than RmTBI, and sleep hygiene should become a priority for adolescent health.

Caffeine consumption during development alters spine density and recovery from repetitive mild traumatic brain injury in young adult rats

“…The NCM task, which was used to assess short‐term working memory (Spanswick & Sutherland, ), involved placing the animals in a particular context, after 3 days of training, with one familiar and one novel object while recording the amount of time spent with each object during a 5‐min trial. Von Frey, which aids in the assessment of pain thresholds and sensitivity (Campana & Rimondini, ; Salberg, ), involved applying pressure to the middle of the animal's hind paw with filaments of increasing size and measuring the mechanical pain response (i.e., the foot withdrawal response). Finally, the forced swim task, which was used to measure depressive‐like behaviour (Yadid, Overstreet, & Zangen, ), required the animals to be placed in a cylindrical container of warm water while their hind leg movement was recorded for instances of immobility.…”

Clinical Relevance of Behavior Testing in Animal Models of Traumatic Brain Injury

“…It should also be noted that there is still a limited understanding of the causal pathological mechanisms that underlie the various behavioral changes that occur in TBI patients or animal TBI models. This makes it difficult to determine whether the behavioral changes after TBI in patients and rodents are attributed to the same pathological mechanisms, and future research is needed to clarify 85,89,112,123,130,131,149,153,162,163,169,181,183,192,213,225,235,236,245,252,254,255,261 Elevated zero maze this and further validate the relevance of behavioral outcomes in animal models. With that said, there is evidence that animal models can induce pathologies (as alluded to above) and behavioral abnormalities (as described below) that are similar to those that occur in human TBI.…”

Neuroendocrine Whiplash: Slamming the Breaks on Anabolic-Androgenic Steroids Following Repetitive Mild Traumatic Brain Injury in Rats May Worsen Outcomes

“…Rats underwent a behavioral test battery consisting of 6 behavioral tasks designed to measure post-concussive symptomology (31, 32). Beam walking is a test for balance and motor coordination used to measure hindleg foot slips on a tapered beam described in detail by Schallert et al (33).…”