Environmental enrichment protects against functional deficits caused by traumatic brain injury.

Environmental enrichment (EE) increases cortical weight, neuronal density, dendritic branching, and angiogenesis, all of which may be critical for functional recovery following insult. Our study was designed to determine possible benefits of pre-exposure to EE in preventing functional deficits following traumatic brain injury (TBI) to the prefrontal cortex. To examine the benefit of EE, adult male rats were placed in an enriched environment for 15 days. Enrichment was provided through social interaction, exercise, olfactory stimulation, and new objects/toys to explore. Following enrichment, experimental and age-matched controls were subjected to a moderate medial prefrontal cortex injury via controlled cortical impact (CCI). After 1 week recovery, animals were behaviorally tested to assess memory, anxiety, and sensory neglect. Lesion-induced deficits in spatial memory [Morris water maze (MWM)] were significantly attenuated in EE pre-exposed rats 18-21 days following injury. In addition, TBI-induced sensory neglect was significantly reduced in EE rats relative to non-enriched animals. No differences in anxiety-like behavior on the elevated plus maze (EPM) were detected. The behavioral data suggest that EE is neuroprotective when applied prior to TBI, resulting in improved recovery following injury.

The influence of agility training on physiological and cognitive performance.

Agility training (AT) has recently been instituted in several military communities in hopes of improving combat performance and general fitness. The purpose of this study was to determine how substituting AT for traditional military physical training (PT) influences physical and cognitive performance. Forty-one subjects undergoing military technical training were divided randomly into 2 groups for 6 weeks of training. One group participated in standard military PT consisting of calisthenics and running. A second group duplicated the amount of exercise of the first group but used AT as their primary mode of training. Before and after training, subjects completed a physical and cognitive battery of tests including V[Combining Dot Above]O2max, reaction time, Illinois Agility Test, body composition, visual vigilance, dichotic listening, and working memory tests. There were significant improvements within the AT group in V[Combining Dot Above]O2max, Illinois Agility Test, visual vigilance, and continuous memory. There was a significant increase in time-to-exhaustion for the traditional group. We conclude that AT is as effective or more effective as PT in enhancing physical fitness. Further, it is potentially more effective than PT in enhancing specific measures of physical and cognitive performance, such as physical agility, memory, and vigilance. Consequently, we suggest that AT be incorporated into existing military PT programs as a way to improve war-fighter performance. Further, it seems likely that the benefits of AT observed here occur in various other populations.

A mouse model of blast-induced mild traumatic brain injury.

Improvised explosive devices (IEDs) are one of the main causes for casualties among civilians and military personnel in the present war against terror. Mild traumatic brain injury from IEDs induces various degrees of cognitive, emotional and behavioral disturbances but knowledge of the exact brain pathophysiology following exposure to blast is poorly understood. The study was aimed at establishing a murine model for a mild BI-TBI that isolates low-level blast pressure effects to the brain without systemic injuries. An open-field explosives detonation was used to replicate, as closely as possible, low-level blast trauma in the battlefield or at a terror-attack site. No alterations in basic neurological assessment or brain gross pathology were found acutely in the blast-exposed mice. At 7 days post blast, cognitive and behavioral tests revealed significantly decreased performance at both 4 and 7 m distance from the blast (5.5 and 2.5 PSI, respectively). At 30 days post-blast, clear differences were found in animals at both distances in the object recognition test, and in the 7 m group in the Y maze test. Using MRI, T1 weighted images showed an increased BBB permeability 1 month post-blast. DTI analysis showed an increase in fractional anisotropy (FA) and a decrease in radial diffusivity. These changes correlated with sites of up-regulation of manganese superoxide dismutase 2 in neurons and CXC-motif chemokine receptor 3 around blood vessels in fiber tracts. These results may represent brain axonal and myelin abnormalities. Cellular and biochemical studies are underway in order to further correlate the blast-induced cognitive and behavioral changes and to identify possible underlying mechanisms that may help develop treatment- and neuroprotective modalities.

Enhanced neurorehabilitation techniques in the DVBIC Assisted Living Pilot Project.

Traumatic Brain Injury has been labeled the "silent epidemic" in our current wars. Both CBO and the RAND reports predict that the costs of these injuries will be both extensive and enduring. The projected costs are based not only upon the loss contribution of these warriors to our economy, but also the long-term medical and assistive care that will be needed to support these veterans for decades to come. Thus, the primary goal of the Assisted Living Pilot Project (ALPP) at the Defense and Veterans Brain Injury Center - Johnstown (DVBIC-J) is to promote the ability of the injured warrior to move from assisted living to living independently and to be self-supporting by providing a continuum of care. To accomplish this goal the DVBIC-J ALPP is providing full set of traditional services (physical, occupational, speech, psychological/cognitive, social/familial, vocational, and spiritual), along with "cutting-edge" rehabilitative treatment technologies. These cutting-edge therapies include transdisciplinary clinical consultations, interactive patient and family counseling, and telemedicine-teleconferencing for clinical evaluations and family/significant other care participation. These services will be available to those who require assisted living through their progression to community re-entry. The ALPP also serves as a vehicle for clinical trials to investigate the effects of an enriched environment (e.g., recreational therapies, massage, multisensory stimulation, etc.) on neurorehabilitation therapy, rural telemedicine for servicemembers with traumatic brain injury, and long-term outcome measures of those who have received neurorehabilitation services at the DVBIC-J site. DVBIC-J is also developing collaborative projects with universities and private industry to create an incubator for new rehabilitation technologies. The technologies that DVBIC-J will be focusing on will include assistive technologies (to assist cognitive, physical, and communicative impairments), virtual and augmented reality simulations (for both diagnosis and treatment of TBI and PTSD), and telecommunication technologies to improve rehabilitation services to those warriors that have returned to their homes in rural areas.

Hypothalamo-pituitary-adrenocortical axis, glucocorticoids, and neurologic disease.

Neurologic diseases are often accompanied by significant life stress and consequent increases in stress hormone levels. Glucocorticoid stress hormones are known to have deleterious interactions with neurodegenerative processes, and are hypersecreted in neurologic disorders as well as in comorbid psychiatric conditions, such as depression. This article highlights the state of our knowledge on mechanisms controlling activation and inhibition of glucocorticoid secretion, outlines signaling mechanisms used by these hormones in neural tissue, and describes how endogenous glucocorticoids can mediate neuronal damage in various models of neurologic disease. The article highlights the importance of controlling stress and consequent stress hormone secretion in the context of neurologic disease states.