Journal of neurotrauma
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Journal of neurotrauma · Nov 2012
A relatively brief exposure to environmental enrichment after experimental traumatic brain injury confers long-term cognitive benefits.
It is well established that a relatively brief exposure to environmental enrichment (EE) enhances motor and cognitive performance after experimental traumatic brain injury (TBI), but it is not known whether the benefits can be sustained after EE is discontinued. To address this important rehabilitation-relevant concern, anesthetized rats received a controlled cortical impact (CCI) or sham injury, and for phase 1 of the experiment were randomly assigned to either 3 weeks of EE or standard (STD) housing. Neurobehavioral outcome was assessed by established motor and cognitive tests on postoperative days 1-5 and 14-18, respectively. ⋯ The TBI + EE and TBI + EE + STD groups performed markedly better in the water maze than the TBI + STD group (p<0.0001), and did not differ from one another (p=0.53). These data replicate those of several studies from our laboratory showing that EE enhances recovery after CCI injury, and extend those findings by demonstrating that the cognitive benefits are maintained for at least 6 months post-rehabilitation. The persistent benefits shown with this paradigm provide further support for EE as a pre-clinical model of rehabilitation that can be further explored, either alone or in combination with pharmacotherapies, for optimal neurorehabilitation after TBI.
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Journal of neurotrauma · Nov 2012
Arachidonic acid: a bridge between traumatic brain injury and fracture healing.
Traumatic brain injury (TBI) is associated with enhanced osteogenesis. The aim of this study was to investigate the effect of serum from TBI rats on fracture healing. Results from this study showed that the serum from TBI rats enhanced the expression of bone gamma carboxyglutamate protein (BGLAP), and promoted in vitro proliferation of MC3T3-E1 cells, a mouse osteoblastic cell line. ⋯ Finally, we examined the effects of AA on BGLAP expression and cell proliferation in MC3T3-E1 cells. We found that BGLAP expression and proliferation of osteoblasts were positively regulated in the presence of AA. These findings suggest that the increased AA in serum after TBI may play a key role in enhancing the speed of fracture healing.
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Journal of neurotrauma · Nov 2012
Treatment of traumatic brain injury using zinc-finger protein gene therapy targeting VEGF-A.
Vascular endothelial growth factor (VEGF) plays a role in angiogenesis and has been shown to be neuroprotective following central nervous system trauma. In the present study we evaluated the pro-angiogenic and neuroprotective effects of an engineered zinc-finger protein transcription factor transactivator targeting the vascular endothelial growth factor A (VEGF-ZFP). We used two virus delivery systems, adeno-virus and adeno-associated virus, to examine the effects of early and delayed VEGF-A upregulation after brain trauma, respectively. ⋯ Adv-VEGF-ZFP treatment significantly improved fEPSP values (p=0.007) in the CA1 region relative to injury alone. Treatment with AAV2-VEGF-ZFP resulted in improved post-injury microvascular diameter and improved functional recovery on the balance beam and rotarod task at 30 days post-injury. Collectively, the results provide supportive evidence for the concept of acute and delayed treatment following TBI using VEGF-ZFP to induce angiogenesis, reduce cell death, and enhance functional recovery.
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Journal of neurotrauma · Nov 2012
Gracile neurons contribute to the maintenance of neuropathic pain in peripheral and central neuropathic models.
In the present study, we compared the roles of gracile neurons in mechanically-induced neuropathic pain caused by spinal injury and L5 spinal nerve ligation in rats. Behavioral and electrophysiological methods were used to measure mechanical allodynia in the hindpaws, and excitability of the gracile neurons in the medulla, respectively. In the spinal hemisection and spinal contusion models, mechanical allodynia developed in both hindpaws and lasted over a month. ⋯ In addition, WDR neuronal activity at the ipsilateral gracile neurons showed a significant increase with non-noxious mechanical stimuli, whereas the LT neurons did not show significant changes (*p<0.05). Similarly to the hemisection model, a lesion of the gracile nucleus attenuated the mechanical allodynia in spinal nerve ligation models. The present data suggest that gracile neurons contribute to the maintenance of non-noxious mechanically-induced neuropathic pain in both hemisection- and ligation-induced neuropathic pain in rats.
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Journal of neurotrauma · Nov 2012
ReviewA systematic review of diffusion tensor imaging findings in sports-related concussion.
Sports-related concussion (SRC) is typically associated with functional, as opposed to structural, injury. The results of traditional structural neuroimaging techniques used to assess SRC tend to be normal in many athletes, and are only clinically helpful in ruling out a more serious injury. Diffusion tensor imaging (DTI) has increasingly been touted as a method offering greater clinical potential in mild traumatic brain injury (mTBI). ⋯ Seven of eight studies reported some type of DTI abnormality, although the neuroanatomical sites involved varied. Although considerable methodological variations exist across studies, the current review suggests that DTI may possess adequate diagnostic sensitivity to detect SRC in affected athletes. Further longitudinal studies are required to demonstrate its discriminate validity and prognostic capacity within this field.