Alcohol use disorder is a major public health concern in the United States. Recent work has suggested a link between chronic alcohol consumption and the development of tauopathy disorders, such as Alzheimer's disease and frontotemporal dementia. However, relatively little work has investigated changes in neural circuitry involved in both tauopathy disorders and alcohol use disorder.
View Article and Find Full Text PDFBackground: The stentless porcine aortic root prosthesis (SPAR) has been described as a suitable valve for right ventricular outflow tract reconstruction (RVOTR). Indiana University Methodist Hospital in Indianapolis, Indiana began using this valve for RVOTR in 1998. This study reports medium-term to late- term outcomes of the valve in the pulmonary position.
View Article and Find Full Text PDFThe cochlear nucleus (CN) transforms the spike trains of spiral ganglion cells into a set of sensory representations that are essential for auditory discriminations and perception. These transformations require the coordinated activity of different classes of neurons that are embryologically derived from distinct sets of precursors. Decades of investigation have shown that the neurons of the CN are differentiated by their morphology, neurotransmitter receptors, ion channel expression and intrinsic excitability.
View Article and Find Full Text PDFDendritic spines in the developing mammalian neocortex are initially overproduced and then eliminated during adolescence to achieve appropriate levels of excitation in mature networks. We show here that the L1 family cell adhesion molecule Close Homolog of L1 (CHL1) and secreted repellent ligand Semaphorin 3B (Sema3B) function together to induce dendritic spine pruning in developing cortical pyramidal neurons. Loss of CHL1 in null mutant mice in both genders resulted in increased spine density and a greater proportion of immature spines on apical dendrites in the prefrontal and visual cortex.
View Article and Find Full Text PDFThe neural cell adhesion molecule (NCAM), has been shown to be an obligate regulator of synaptic stability and pruning during critical periods of cortical maturation. However, the functional consequences of NCAM deletion on the organization of inhibitory circuits in cortex are not known. In vesicular gamma-amino butyric acid (GABA) transporter (VGAT)-channelrhodopsin2 (ChR2)-enhanced yellow fluorescent protein (EYFP) transgenic mice, NCAM is expressed postnatally at perisomatic synaptic puncta of EYFP-labeled parvalbumin, somatostatin and calretinin-positive interneurons, and in the neuropil in the anterior cingulate cortex (ACC).
View Article and Find Full Text PDFThe thalamus acts as a conduit for sensory and other information traveling to the cortex. In response to continuous sensory stimulation in vivo, the firing rate of thalamocortical neurons initially increases, but then within a minute firing rate decreases and T-type Ca(2+) channel-dependent action potential burst firing emerges. While neuromodulatory systems could play a role in this inhibitory response, we instead report a novel and cell-autonomous inhibitory mechanism intrinsic to the thalamic relay neuron.
View Article and Find Full Text PDFStudy Design: Systematic review of literature.
Objective: To perform a comprehensive English language systematic literature review of proximal junctional kyphosis (PJK) and proximal junctional failure (PJF), concentrating on incidence, risk factors, health related quality of life impact, prevention strategy, and classification systems.
Summary Of Background Data: PJK and PJF are well described clinical pathologies and are a frequent cause of revision surgery.
Neuroprosthetic approaches have tremendous potential for the treatment of injuries to the brain and spinal cord by inducing appropriate neural activity in otherwise disordered circuits. Substantial work has demonstrated that stimulation applied to both the central and peripheral nervous system leads to immediate and in some cases sustained benefits after injury. Here we focus on cervical intraspinal microstimulation (ISMS) as a promising method of activating the spinal cord distal to an injury site, either to directly produce movements or more intriguingly to improve subsequent volitional control of the paretic extremities.
View Article and Find Full Text PDFObjective: Intraspinal microstimulation (ISMS) is a promising method for reanimating paralyzed limbs following neurological injury. ISMS within the cervical and lumbar spinal cord is capable of evoking a variety of highly-functional movements prior to injury, but the ability of ISMS to evoke forelimb movements after cervical spinal cord injury is unknown. Here we examine the forelimb movements and muscles activated by cervical ISMS both before and after contusion injury.
View Article and Find Full Text PDFIntroduction: We postulated that the risk of venous thromboembolic disease (VTE) may persist after discharge and tested this hypothesis in patients undergoing colorectal resection for cancer.
Methods: The American College of Surgeons National Surgery Quality Improvement Program database was queried for patients undergoing colorectal resections for cancer from 2005 to 2009. The outcome analyzed was a 30-day deep vein thrombosis (DVT) and/or pulmonary embolism (PE).
The calcium control hypothesis posits that postsynaptic calcium increases are required to trigger synaptic plasticity, with large increases inducing LTP and small increases inducing LTD. In CA1 of the hippocampus, however, LTD induced by chemical activation of metabotropic glutamate receptors (agonist-LTD) is independent of increases in postsynaptic calcium. Here we tested whether LTD induced by pairing of presynaptic stimulation with postsynaptic depolarization (synaptic-LTD) is similarly calcium-independent.
View Article and Find Full Text PDFActivity-dependent redistribution of ion channels mediates neuronal circuit plasticity and homeostasis, and could provide pro-epileptic or compensatory anti-epileptic responses to a seizure. Thalamocortical neurons transmit sensory information to the cerebral cortex and through reciprocal corticothalamic connections are intensely activated during a seizure. Therefore, we assessed whether a seizure alters ion channel surface expression and consequent neurophysiologic function of thalamocortical neurons.
View Article and Find Full Text PDFBackground: Packed red blood cell (PRBC) transfusion suppresses immunity and increases morbidity and mortality. Leukocyte reduction has failed to abrogate these effects, thus implicating red blood cells themselves or their components. PRBC impair proliferation of immortal (Jurkat) T cells by depleting arginine from the extracellular environment.
View Article and Find Full Text PDFStudy Design: Case series, level of evidence therapeutic IV.
Objective: Examine the results of bilateral iliac wing fixation in long fusions to the pelvis in ambulatory adult patients.
Summary Of Background Data: Adult spinal deformity surgery is an endeavor often fraught with complications.
Background: Transfusion of packed red blood cells (PRBC) suppresses immunity, but the mechanisms are incompletely understood. PRBCs contain arginase, an enzyme which converts arginine to ornithine and depletes arginine in vitro. Arginine depletion suppresses proliferation of Jurkat T cells in other models.
View Article and Find Full Text PDFSensory signals of widely differing dynamic range and intensity are transformed into a common firing rate code by thalamocortical neurons. While a great deal is known about the ionic currents, far less is known about the specific channel subtypes regulating thalamic firing rates. We hypothesized that different K(+) and Ca(2+) channel subtypes control different stimulus-response curve properties.
View Article and Find Full Text PDFSilent synapses display no excitatory post-synaptic currents (EPSCs) at resting potentials, but can conduct at depolarized potentials. In the hippocampal CA1 region of young animals, conversion of silent synapses to functional synapses occurs rapidly after pairing post-synaptic depolarization with 1Hz pre-synaptic stimulation, a protocol that also induces long-term potentiation (LTP). LTP appears to have a decremental phase and a sustained phase.
View Article and Find Full Text PDFMyotonic dystrophy (DM) is associated with an expanded triplet repeat in the 3'-untranslated region of the gene for myotonic dystrophy protein kinase (DMPK), which may reduce DMPK expression. It is unclear how reduced DMPK expression might contribute to the symptoms of DM because the normal function of DMPK is not yet understood. Thus we investigated the function of DMPK to gain insight into how reduced DMPK expression might lead to cognitive dysfunction in DM.
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