Neurosciences Commons^™

The Mind-Body Problem; Three Equations And One Solution Represented By Immaterial-Material Data, Ion G. Motofei, David L. Rowland

Journal of Mind and Medical Sciences

Human life occurs within a complex bio-psycho-social milieu, a heterogeneous system that is integrated by multiple bidirectional interrelations existing between the abstract-intangible ideas and physical-chemical support of environment. The mind is thus placed between the abstract ideas/ concepts and neurobiological brain that is further connected to environment. In other words, the mind acts as an interface between the immaterial (abstract/ intangible) data and material (biological) support. The science is unable to conceives and explains an interaction between the immaterial and material domains (to understand nature of the mind), this question generating in literature the mind-body problem. We have published in …

Single Session Low Frequency Left Dorsolateral Prefrontal Transcranial Magnetic Stimulation Changes Neurometabolite Relationships In Healthy Humans, Matthew Sherwood, Richard A. Mckinley, Danielle Boeke, Jason G. Parrker, Lindsey K. Mcintire, Justin M. Nelson, Catherine Fletchall, Natasha Alexander, Amanda Mcconnell, Chuck Goodyear, Jeremy T. Nelson, Nathaniel R. Bridges

Neuroscience, Cell Biology & Physiology Faculty Publications

Background: Dorsolateral prefrontal cortex (DLPFC) low frequency repetitive transcranial magnetic stimulation (LF-rTMS) has shown promise as a treatment and investigative tool in the medical and research communities. Researchers have made significant progress elucidating DLPFC LF-rTMS effects—primarily in individuals with psychiatric disorders. However, more efforts investigating underlying molecular changes and establishing links to functional and behavioral outcomes in healthy humans are needed. Objective: We aimed to quantify neuromolecular changes and relate these to functional changes following a single session of DLPFC LF-rTMS in healthy participants. Methods: Eleven participants received sham-controlled neuronavigated 1 Hz rTMS to the region most activated by a …

Muscle Nicotinic Acetylcholine Receptors May Mediate Trans-Synaptic Signaling At The Mouse Neuromuscular Junction, Xueyong Wang, J. Michael Mcintosh, Mark M. Rich

Neuroscience, Cell Biology & Physiology Faculty Publications

Block of neurotransmitter receptors at the neuromuscular junction (NMJ) has been shown to trigger upregulation of the number of synaptic vesicles released (quantal content, QC), a response termed homeostatic synaptic plasticity. The mechanism underlying this plasticity is not known. Here, we used selective toxins to demonstrate that block of α1-containing nicotinic acetylcholine receptors (nAChRs) at the NMJ of male and female mice triggers the upregulation of QC. Reduction of current flow through nAChRs, induced by drugs with antagonist activity, demonstrated that reduction in synaptic current per se does not trigger upregulation of QC. These data led to the remarkable conclusion …

Trpm7 Current Inactivation: Evidence For Inside-Out Signaling, Tetyana Zhelay, J. Ashot Kozak

Neuroscience, Cell Biology & Physiology Faculty Publications

TRPM7 channels conduct metal cations such as Na+, K+, Ca2+ and Mg2+. In the presence of external Ca2+/Mg2+ TRPM7 has a steeply outwardly rectifying current-voltage (I-V) relation. In the absence of Ca2+/Mg2+ the IV becomes semi-linear. This has been explained by the removal of pore blockade by divalent cations (e.g. Ca2+o/Mg2+o). TRPM7 channels are inhibited by cytoplasmic Mg2+ in a voltage-independent manner, primarily by a reversible reduction in the overall number of conducting channels. Here, we have examined the consequences of external Ca2+ removal and reintroduction on TRPM7 current kinetics. In whole-cell patch clamp with low internal Mg2+, we rapidly …

Inactivation Of Trpm7 Kinase In Mice Results In Enlarged Spleens, Reduced T-Cell Proliferation And Diminished Store-Operated Calcium Entry, Pavani Beesetty, Krystyna Blanka Wieczerzak, Jennifer Gibson, Taku Kaitsuka, Charles Tuan Luu, Masayuki Matsushita, J. Ashot Kozak

Neuroscience, Cell Biology & Physiology Faculty Publications

T lymphocytes enlarge (blast) and proliferate in response to antigens in a multistep program that involves obligatory cytosolic calcium elevations. Store-operated calcium entry (SOCE) pathway is the primary source of Ca2+ in these cells. Here, we describe a novel modulator of blastogenesis, proliferation and SOCE: the TRPM7 channel kinase. TRPM7 kinase-dead (KD) K1646R knock-in mice exhibited splenomegaly and impaired blastogenic responses elicited by PMA/ionomycin or anti-CD3/CD28 antibodies. Splenic T-cell proliferation in vitro was weaker in the mutant compared to wildtype littermates. TRPM7 current magnitudes in WT and KD mouse T cells were, however, similar. We tested the dependence of T-cell …

Finasteride As A Model For Personalized Medicine, Ion G. Motofei, David L. Rowland, Ioana Păunică, Octavian C. Tănăsescu, Petrişor Banu, Stana Păunică

Journal of Mind and Medical Sciences

The side effects of Finasteride are currently a subject of controversy. Some studies report minor or acceptable adverse effects, which decrease after a variable period of time so that they do not necessitate terminating Finasteride administration. However, several clinical and neuro-endocrine studies show that some adverse effects persist indefinitely in the form of post-Finasteride syndrome, even after the drug cessation. This paper presents a possible explanation for these inconsistent findings. First, the study design of either informing or not informing patients prior therapy about possible adverse effects can influence the incidence and magnitude of reported adverse effects. Second, structural and …

A Protocol For The Administration Of Real-Time Fmri Neurofeedback Training, Matthew Sherwood, Emily E. Diller, Elizabeth Ey, Subhashini Ganapathy, Jeremy T. Nelson, Jason G. Parker

Neuroscience, Cell Biology & Physiology Faculty Publications

Neurologic disorders are characterized by abnormal cellular-, molecular-, and circuit-level functions in the brain. New methods to induce and control neuroplastic processes and correct abnormal function, or even shift functions from damaged tissue to physiologically healthy brain regions, hold the potential to dramatically improve overall health. Of the current neuroplastic interventions in development, neurofeedback training (NFT) from functional Magnetic Resonance Imaging (fMRI) has the advantages of being completely non-invasive, non-pharmacologic, and spatially localized to target brain regions, as well as having no known side effects. Furthermore, NFT techniques, initially developed using fMRI, can often be translated to exercises that can …

Mixed-Mode Oscillations In Pyramidal Neurons Under Antiepileptic Drug Conditions, Babak V-Ghaffari, M. Kouhnavard, Sherif M. Elbasiouny

Neuroscience, Cell Biology, & Physiology Faculty Publications

Subthreshold oscillations in combination with large-amplitude oscillations generate mixedmode oscillations (MMOs), which mediate various spatial and temporal cognition and memory processes and behavioral motor tasks. Although many studies have shown that canard theory is a reliable method to investigate the properties underlying the MMOs phenomena, the relationship between the results obtained by applying canard theory and conductancebased models of neurons and their electrophysiological mechanisms are still not well understood. The goal of this study was to apply canard theory to the conductance-based model of pyramidal neurons in layer V of the Entorhinal Cortex to investigate the properties of MMOs under …

Regulation Of Trpm7 By Cytosolic Mg2+ And Ph: Insights From Vsp Expression, Pavani Beesetty, Krystyna Blanka Wieczerzak, Tatyana Zhelay, Taku Kaitsuka, Masayuki Matsushita, J. Ashot Kozak

Neuroscience, Cell Biology & Physiology Faculty Publications

TRPM7 is an ion channel/protein kinase belonging to TRP melastatin and eEF2 kinase families. Under physiological conditions, most native TRPM7 channels are inactive, due to inhibition by cytoplasmic Mg2+, protons and polyamines. ITRPM7 is strongly potentiated when cell cytosol is depleted of Mg2+ or alkalinized. In Jurkat T cells, Mg2+ inhibition involves a high and a low affinity inhibitor sites, whereas proton inhibition involves only one site. Like many other TRP channels, TRPM7 is activated by PI(4,5)P2 and suppressed by its hydrolysis. Here we examined Mg2+ and pH inhibition of native TRPM7 channels in HEK293 cells overexpressing voltage-sensitive phospholipid phosphatase …

Analysis Of Proprioceptive Sensory Innervation Of The Mouse Soleus: A Whole-Mount Muscle Approach, Martha Jean Sonner, Marie C. Walters, David R. Ladle

Neuroscience, Cell Biology & Physiology Faculty Publications

Muscle proprioceptive afferents provide feedback critical for successful execution of motor tasks via specialized mechanoreceptors housed within skeletal muscles: muscle spindles, supplied by group Ia and group II afferents, and Golgi tendon organs, supplied by group Ib afferents. The morphology of these proprioceptors and their associated afferents has been studied extensively in the cat soleus, and to a lesser degree, in the rat; however, quantitative analyses of proprioceptive innervation in the mouse soleus are comparatively limited. The present study employed genetically-encoded fluorescent reporting systems to label and analyze muscle spindles, Golgi tendon organs, and the proprioceptive sensory neuron subpopulations supplying …

Survival And Growth Of C57bl/6j Mice Lacking The Bk Channel, Kcnma1: Lower Adult Body Weight Occurs Together With Higher Body Fat, Susan T. Halm, Michael A. Bottomley, Mohammed M. Almutairi, Mauricio Di Fulvio, Dan R. Halm

Neuroscience, Cell Biology & Physiology Faculty Publications

Big conductance potassium (BK) channels contribute to K⁺ flow and electrical behavior in many cell types. Mice made null for the gene (Kcnma1) producing the BK channel (BK^KO) exhibit numerous deficits in physiological functions. Breeding mice lacking a single allele of Kcnma1 (C57BL/6J background) had litter sizes of approximately eight pups. For the period of maternal care (P0– P21), pup deaths peaked at P1 with a second less severe interval of death peaking near P13. Early deaths were twice as likely during a 20-month period of building construction compared with the quiescent period after cessation of construction. Births …

Evaluating Cardiovascular Dysfunction During Increased Activity And Exercise Rehabilitation Following Incomplete Thoracic Spinal Cord Injury In The Adult Rat., Kathryn A. Harman

Electronic Theses and Dissertations

Spinal cord injury (SCI) results in whole-body dysfunction. While the majority of SCI research is focused on improving locomotor function after injury, cardiovascular (CV) disease continues to be the leading cause of morbidity in the chronic SCI patient population. The combination of injury-induced destruction of autonomic pathways, maladaptive plasticity within lumbosacral circuits, and the progressive decline in physical fitness contribute to the poor CV status of SCI individuals. Currently, there is little emphasis on implementing appropriately-timed acute rehabilitation techniques aimed to curtail maladaptive remodeling and improve CV outcomes. Furthermore, no pre-clinical or clinical studies have investigated the most appropriate time-course …

Dissecting The Physiological Roles Of Ulk1/2 In The Mouse Brain, Bo Wang

Theses and Dissertations (ETD)

Mammalian UNC-51–like kinases 1 and 2 (ULK1 and ULK2), Caenorhabditis elegans UNC-51 and Drosophila melanogaster Atg1 are redundant serine/threonine kinases that regulate flux through the autophagy pathway in response to various types of cellular stress. C. elegans UNC-51 and D. melanogaster Atg1 also promote axonal growth and defasciculation, and disruption of these genes results in defects in axon guidance in invertebrates. Germline Ulk1/2-deficient mice die perinatally. Therefore, we used a conditional-knockout approach to investigate the roles of ULK1/2 in the brain. Mice lacking Ulk1 and Ulk2 in their central nervous systems (CNS) showed defects in axonal pathfinding and defasciculation affecting …

Positive Allosteric Modulator Of Gabab Receptor Alters Behavioral Effects But Not Afterdischarge Progression Induced By Partial Hippocampal Kindling., L Stan Leung, Miao Jin, Liangwei Chu, Jingyi Ma

Physiology and Pharmacology Publications

Hippocampal seizures decreased the function of GABAB receptors, which may further increase seizure susceptibility and contribute to development of schizophrenia-like behaviors. Recent literature indicates that GABAB receptor agonist may normalize schizophrenia-like behaviors and prevent drug-induced behavioral sensitization. We hypothesized that positive modulation of GABAB receptor function during seizure induction will reduce seizure-induced schizophrenia-like behaviors. Using a partial hippocampal kindling model, afterdischarges were induced after injection of saline or dimethyl sulfoxide (vehicle-kindled rats), or a GABAB receptor positive allosteric modulator CGP7930, at 1 mg/kg i.p. (CGP1-kindled) or 5 mg/kg i.p. (CGP5-kindled). The increase in the primary afterdischarge duration during kindling was …

Reduced Motor Neuron Excitability Is An Important Contributor To Weakness In A Rat Model Of Sepsis, Paul Nardelli, Jacob A. Vincent, Randall K. Powers, Timothy C. Cope, Mark M. Rich

Neuroscience, Cell Biology & Physiology Faculty Publications

The mechanisms by which sepsis triggers intensive care unit acquired weakness (ICUAW) remain unclear. We previously identified difficulty with motor unit recruitment in patients as a novel contributor to ICUAW. To study the mechanism underlying poor recruitment of motor units we used the rat cecal ligation and puncture model of sepsis. We identified striking dysfunction of alpha motor neurons during repetitive firing. Firing was more erratic, and often intermittent. Our data raised the possibility that reduced excitability of motor neurons was a significant contributor to weakness induced by sepsis. In this study we quantified the contribution of reduced motor neuron …

Combining Real-Time Fmri Neurofeedback Training Of The Dlpfc With N-Back Practice Results In Neuroplastic Effects Confined To The Neurofeedback Target Region, Matthew Sherwood, Michael P. Weisend, Jessica H. Kane, Jason G. Parker

Neuroscience, Cell Biology & Physiology Faculty Publications

In traditional fMRI, individuals respond to exogenous stimuli and are naïve to the effects of the stimuli on their neural activity patterns. Changes arising in the fMRI signal are analyzed post-hoc to elucidate the spatial and temporal activation of brain regions associated with the tasks performed. The advent of real-time fMRI has enabled a new method to systematically alter brain activity across space and time using neurofeedback training (NFT), providing a new tool to study internally-driven processes such as neuroplasticity. In this work, we combined n-back practice with fMRI-NFT of the left dorsolateral prefrontal cortex (DLPFC) to better understand the …

Synapse Formation In Monosynaptic Sensory–Motor Connections Is Regulated By Presynaptic Rho Gtpase Cdc42, Fumiyasu Imai, David R. Ladle, Jennifer R. Leslie, Xin Duan, Tilat A. Rizvi, Georgianne M. Ciraolo, Yi Zheng, Yutaka Yoshida

Neuroscience, Cell Biology & Physiology Faculty Publications

Spinal reflex circuit development requires the precise regulation of axon trajectories, synaptic specificity, and synapse formation. Of these three crucial steps, the molecular mechanisms underlying synapse formation between group Ia proprioceptive sensory neurons and motor neurons is the least understood. Here, we show that the Rho GTPase Cdc42 controls synapse formation in monosynaptic sensory–motor connections in presynaptic, but not postsynaptic, neurons. In mice lacking Cdc42 in presynaptic sensory neurons, proprioceptive sensory axons appropriately reach the ventral spinal cord, but significantly fewer synapses are formed with motor neurons compared with wild-type mice. Concordantly, electrophysiological analyses show diminished EPSP amplitudes in monosynaptic …

Role Of Slit2 In Reducing Complications After Surgical Brain Injury, Prativa Sherchan

Loma Linda University Electronic Theses, Dissertations & Projects

Surgical brain injury (SBI) is the inadvertent injury to brain tissue at the perisurgical site which occurs due to neurosurgical maneuvers such as incision, retraction, and electrocoagulation that can result in post-operative complications. Blood brain barrier (BBB) disruption and neuroinflammation are major pathophysiological consequences after neurosurgical injury. Blood brain barrier dysfunction leads to increased influx of water and plasma proteins as well as peripheral immune cell infiltration into the brain parenchyma that further potentiates brain edema and worsens post-operative neurological function. Activated resident immune cells and infiltrated peripheral immune cells release inflammatory mediators and promote oxidative stress and cell death …

Mitogenic Activation And Proliferation Of T Lymphocytes In Trpm7 Kinase-Dead Mutant Mice, Pavani Beesetty, Masayuki Matsushita, J. Ashot Kozak

Neuroscience, Cell Biology & Physiology Faculty Publications

Calcium and magnesium ions have been implicated in T lymphocyte proliferation in response to antigen recognition. Specifically, it is believed that calcium and magnesium elevations in the cytoplasm are necessary for efficient T cell proliferation. Research over the past two decades has focused on identifying the plasma membrane ion channels responsible for governing Ca2+ influx in lymphocytes and Orai-STIM, Kv1.3 and KCa3.1 channels were shown to be crucial for persistent calcium mobilization. Pharmacologic or genetic suppression of calcium influx gives rise to lymphoproliferative defects. In addition to Ca2+, several studies have demonstrated that Mg2+ influx positively regulates proliferation. TRPM7 is …

Reversible Recruitment Of A Homeostatic Reserve Pool Of Synaptic Vesicles Underlies Rapid Homeostatic Plasticity Of Quantal Content, Xueyong Wang, Martin J. Pinter, Mark M. Rich

Neuroscience, Cell Biology & Physiology Faculty Publications

Homeostatic regulation is essential for the maintenance of synaptic strength within the physiological range. The current study is the first to demonstrate that both induction and reversal of homeostatic upregulation of synaptic vesicle release can occur within seconds of blocking or unblocking acetylcholine receptors at the mouse neuromuscular junction. Our data suggest that the homeostatic upregulation of release is due to Ca²⁺-dependent increase in the size of the readily releasable pool (RRP). Blocking vesicle refilling prevented upregulation of quantal content (QC), while leaving baseline release relatively unaffected. This suggested that the upregulation of QC was due to mobilization …

Protein Kinase A And Epac Mediate Chronic Pain After Injury: Prolonged Inhibition By Endogenous Y1 Receptors In Dorsal Horn, Weisi Fu

Theses and Dissertations--Physiology

Inflammation or nerve injury sensitizes several populations of nociceptive neurons in the dorsal horn of the spinal cord, including those that express the neuropeptide Y (NPY) Y1 receptor (Y1R). Our overall hypothesis is that after tissue or nerve injury, these Y1R-expressing neurons enter a state of latent sensitization (LS) that contributes to vulnerability to the development of chronic pain; furthermore, LS is under the tonic inhibitory control of endogenous Y1R signaling. First, we evaluated the intracellular signaling pathways that become activated in Y1R-expressing neurons and participate in LS. To do this, we established behavioral models of inflammatory or neuropathic pain, …

Histological And Behavioral Consequences Of Repeated Mild Traumatic Brain Injury In Mice, Amanda Nicholle Bolton Hall

Theses and Dissertations--Physiology

The majority of the estimated three million traumatic brain injuries that occur each year are classified as “mild” and do not require surgical intervention. However, debilitating symptoms such as difficulties focusing on tasks, anxiety, depression, and visual deficits can persist chronically after a mild traumatic brain injury (TBI) even if an individual appears “fine”. These symptoms have been observed to worsen or be prolonged when an individual has suffered multiple mild TBIs. To test the hypothesis that increasing the amount of time between head injuries can reduce the histopathological and behavioral consequences of repeated mild TBI, a mouse model of …

Hiv-1-Tat Protein Inhibits Sc35-Mediated Tau Exon 10 Inclusion Through Up-Regulation Of Dyrk1a Kinase, Ferdous Kadri, Marco Pacifici, Anna Wilk, Amanda Parker-Struckhoff, Luis Del Valle, Kurt F. Hauser, Pamela E. Knapp, Christopher Parsons, Duane Jeansonne, Adam Lassak, Francesca Peruzzi

School of Medicine Faculty Publications

The HIV-1 transactivator protein Tat is implicated in the neuronal damage that contributes to neurocognitive impairment affecting people living with HIV/AIDS. Aberrant splicing of TAU exon 10 results in tauopathies characterized by alterations in the proportion of TAU isoforms containing three (3R) or four (4R) microtubule-binding repeats. The splicing factor SC35/SRSF2 binds to nuclear RNA and facilitates the incorporation of exon 10 in the TAU molecule. Here, we utilized clinical samples, an animal model, and neuronal cell cultures and found that Tat promotes TAU 3R up-regulation through increased levels of phosphorylated SC35, which is retained in nuclear speckles. This mechanism …

Plastin 3 Expression Does Not Modify Spinal Muscular Atrophy Severity In The ∆7 Sma Mouse, Vicki L. Mcgovern, Aurelie Massoni-Laporte, Xueyong Wang, Thanh T. Le, Hao T. Le, Mark M. Rich, Arthur H. M. Burghes

Neuroscience, Cell Biology & Physiology Faculty Publications

Spinal muscular atrophy is caused by loss of the SMN1 gene and retention of SMN2. TheSMN2 copy number inversely correlates with phenotypic severity and is a modifier of disease outcome. The SMN2 gene essentially differs from SMN1 by a single nucleotide in exon 7 that modulates the incorporation of exon 7 into the final SMN transcript. The majority of the SMN2transcripts lack exon 7 and this leads to a SMN protein that does not effectively oligomerize and is rapidly degraded. However theSMN2 gene does produce some full-length SMN and theSMN2 copy number along with how …

Appropriate Timing Of Fluoxetine And Statin Delivery Reduces The Risk Of Secondary Bleeding In Ischemic Stroke Rats, Maria Helen Harley Balch, Moner A. Ragas, Danny Wright, Kenny Reynolds, Bryce Kerr, Adrian M. Corbett

Neuroscience, Cell Biology & Physiology Faculty Publications

Background: Ongoing clinical trials are testing the effect of fluoxetine delivered post-stroke where a majority of patients are taking statins. This study determined the influence of the timing of administration of fluoxetine and statin on the final infarct volume and the risk of secondary bleeding in an animal model of ischemic stroke.

Methods and findings: Ischemic strokes were induced by endothelin-1 injection into two cortical sites of 10-12 month old female rats, targeting the forelimb motor cortex. Combined medications (5 mg/kg fluoxetine and 1 mg/kg simvastatin) were orally administered either beginning 6-12 hours or 20-26 hours after stroke induction and …

Swimming Against The Tide: Investigations Of The C-Bouton Synapse, Adam S. Deardorff, Shannon H. Romer, Patrick M. Sonner, Robert E. W. Fyffe

Neuroscience, Cell Biology & Physiology Faculty Publications

C-boutons are important cholinergic modulatory loci for state-dependent alterations in motoneuron firing rate. m2 receptors are concentrated postsynaptic to C-boutons, and m2 receptor activation increases motoneuron excitability by reducing the action potential afterhyperpolarization. Here, using an intensive review of the current literature as well as data from our laboratory, we illustrate that C-bouton postsynaptic sites comprise a unique structural/functional domain containing appropriate cellular machinery (a “signaling ensemble”) for cholinergic regulation of outward K⁺ currents. Moreover, synaptic reorganization at these critical sites has been observed in a variety of pathologic states. Yet despite recent advances, there are still great challenges …

Role Of Astrocyte Network In Edema After Juvenile Traumatic Brain Injury, Andrew Minoru Fukuda

Loma Linda University Electronic Theses, Dissertations & Projects

Juvenile traumatic brain injury (jTBI) is the leading cause of death and disability in young children and adolescents. Despite its lasting detrimental effects on the developing brain, no pharmacological treatment exists. One of the pathological hallmarks of jTBI is edema. Astrocytes play a key role in the edema process, and have been hypothesized that numerous astrocyte networks allow communication and propagation of edema and secondary injury spread. Two key astrocyte proteins are hypothesized to have a central role in the edema process: Aquaporin 4 (AQP4) and Connexin 43 (Cx43). AQP4 is expressed extensively in astrocyte endfeet, which surrounds the blood …

Motor Axon Synapses On Renshaw Cells Contain Higher Levels Of Aspartate Than Glutamate, Dannette Shanon Richards, Ronald W. Griffith, Shannon H. Romer, Francisco J. Alvarez

Neuroscience, Cell Biology & Physiology Faculty Publications

Motoneuron synapses on spinal cord interneurons known as Renshaw cells activate nicotinic, AMPA and NMDA receptors consistent with co-release of acetylcholine and excitatory amino acids (EAA). However, whether these synapses express vesicular glutamate transporters (VGLUTs) capable of accumulating glutamate into synaptic vesicles is controversial. An alternative possibility is that these synapses release other EAAs, like aspartate, not dependent on VGLUTs. To clarify the exact EAA concentrated at motor axon synapses we performed a quantitative postembedding colloidal gold immunoelectron analysis for aspartate and glutamate on motor axon synapses (identified by immunoreactivity to the vesicular acetylcholine transporter; VAChT) contacting calbindin-immunoreactive (-IR) Renshaw …

Adult Spinal Motoneurones Are Not Hyperexcitable In A Mouse Model Of Inherited Amyotrophic Lateral Sclerosis, Nicolas Delestrée, Marin Manuel, Caroline Iglesias, Sherif M. Elbasiouny, C. J. Heckman, Daniel Zytnicki

Neuroscience, Cell Biology & Physiology Faculty Publications

In amyotrophic lateral sclerosis (ALS), an adult onset disease in which there is progressive degeneration of motoneurones, it has been suggested that an intrinsic hyperexcitability of motoneurones (i.e. an increase in their firing rates), contributes to excitotoxicity and to disease onset. Here we show that there is no such intrinsic hyperexcitability in spinal motoneurones. Our studies were carried out in an adult mouse model of ALS with a mutated form of superoxide dismutase 1 around the time of the first muscle fibre denervations. We showed that the recruitment current, the voltage threshold for spiking and the frequency–intensity gain in the …

Substance P Differentially Modulates Firing Rate Of Solitary Complex (Sc) Neurons From Control And Chronic Hypoxia-Adapted Adult Rats, Nicole L. Nichols, Frank L. Powell, Jay B. Dean, Robert W. Putnam

Neuroscience, Cell Biology & Physiology Faculty Publications

NK1 receptors, which bind substance P, are present in the majority of brainstem regions that contain CO₂/H⁺-sensitive neurons that play a role in central chemosensitivity. However, the effect of substance P on the chemosensitive response of neurons from these regions has not been studied. Hypoxia increases substance P release from peripheral afferents that terminate in the caudal nucleus tractus solitarius (NTS). Here we studied the effect of substance P on the chemosensitive responses of solitary complex (SC: NTS and dorsal motor nucleus) neurons from control and chronic hypoxia-adapted (CHx) adult rats. We simultaneously measured intracellular pH …