Neurosurgery
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Considerable evidence points to cortico-striato-thalamo-cortical circuits in cognitive, limbic, and motor functions. Specifically, the connections between caudate, nucleus accumbens (NAc), and prefrontal cortex have been implicated in behavioral learning and motivation. Precisely timed stimulation of the caudate during a behavioral task enhances learning beyond baseline in normal primates. We test the overarching hypothesis that combined intermittent stimulation of the caudate and NAc leads to enhanced learning. Our specific hypothesis is that there are 2 streams of information processing in the anterior striatum, dorsal and ventral, that perform complementary but different roles. We believe that the dorsal stream, which includes the caudate, is involved in the executive aspect of associative learning, whereas the ventral stream, which includes the NAc, is involved in providing the motivation for the performance of learned behavior. ⋯ Enhancing visuomotor performance may be beneficial to patients who have cognitive-motor deficits caused by traumatic brain injury. Deep brain stimulation strategies augmenting learning and motivational processes could be used in humans to enhance a broad range of functions including gross motor movements and decision making.
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Posttraumatic stress disorder (PTSD) is one of the hallmark conditions of soldiers returning from Operations Iraqi Freedom and Enduring Freedom, with as many as 20% of soldiers affected. Approximately 30% of patients do not respond to conventional treatment, resulting in a significant unmet treatment need. Amygdalar activity is increased in fear learning and PTSD, leading our group and others to hypothesize that amygdalar stimulation may attenuate PTSD-related symptoms. Prior studies showed decreased avoidance behavior with right amygdalar stimulation in a foot-shock paradigm. However, the underlying molecular mechanisms remain incompletely understood. Human and animal studies indicate an anxiolytic function for the neurotransmitter Neuropeptide Y (NPY) in PTSD patients and models of PTSD. We hypothesized that amygdalar stimulation would attenuate behavioral effects in the predator scent model of PTSD and that effects would be mediated by NPY. ⋯ Bilateral amygdalae stimulation attenuated anxiety-like behavior in the predator scent model of PTSD, and treatment was correlated with increased amygdalar NPY. Amygdalar stimulation may alleviate PTSD symptoms, and these data provide the first evidence of a possible underlying molecular mechanism.
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There is no monitoring from the injured spinal cord to define the optimal values of physiological parameters in ICU. We present a technique for continuously monitoring intraspinal pressure (ISP) and spinal cord perfusion pressure (SCPP). ⋯ ISP at the injury site can be measured safely after TSCI. The optimum SCPP varies among TSCI patients.
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To investigate the role of cigarette smoke exposure (CSE) in the regulation of cerebral smooth muscle cell (SMC) phenotypic modulation in a NAPDH (NOX)-dependent manner and its effect on cerebral aneurysm (CA) formation and rupture. ⋯ CSE initiates oxidative stress-induced phenotypic modulation of SMCs leading to CA formation and rupture. These molecular changes implicate oxidative stress in the pathogenesis of CAs and may provide a potential target for future therapeutic strategies.