Breathing above the brain stem

January 24, 2018

What neural circuitry is engaged in the conscious control of breathing? While most neurophysiological research on breathing focuses on the automatic control in the brainstem, a recently-published study provides a novel look at the tracking of the breathing cycle in widespread cortical and limbic sites in humans. In this podcast, Editor-in-Chief Bill Yates (University of Pittsburgh) talks with authors Dr. Jose Herrero (Northwell Health; Feinstein Institute for Medical Research) and Dr. Ashesh Mehta (Northwell Health; Feinstein Institute for Medical Research) about their work. Listen to learn about the recording methods employed, the types of activity discovered, and the implications for volitional control and awareness of breathing.

Breathing above the brain stem: volitional control and attentional modulation in humans
Jose L. Herrero, Simon Khuvis, Erin Yeagle, Moran Cerf, and Ashesh D. Mehta
Journal of Neurophysiology, published online January 3, 2018. DOI: 10.1152/jn.00551.2017.

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ADHD and tactile processing

January 9, 2018

There is much observational and anecdotal evidence for problems with tactile sensory processing in children with ADHD. However, there have previously been virtually no attempts to rigorously quantify differences in tactile sensitivity, habituation, and discrimination between ADHD and non-ADHD children. In this podcast, Editor-in-Chief Bill Yates (University of Pittsburgh) talks with Dr. Nicolaas Puts (Johns Hopkins University School of Medicine; Kennedy Krieger Institute) and Dr. Stewart Mostofsky (Johns Hopkins University School of Medicine; Kennedy Krieger Institute) about a new study which employed recent innovations in neuroimaging to examine whether children with ADHD showed impaired performance on tactile tasks related to GABAergic inhibitory control. Listen to learn about links between ADHD and neural inhibition, the methods used to test tactile performance, and the specific findings of altered tactile processing in children with ADHD.

Altered tactile sensitivity in children with attention-deficit hyperactivity disorder
Nicolaas A. J. Puts, Ashley D. Harris, Mark Mikkelsen, Mark Tommerdahl, Richard A. E. Edden, and Stewart H. Mostofsky
Journal of Neurophysiology, published online November 30, 2017. DOI: 10.1152/jn.00087.2017.

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Tests of the sorption and olfactory ‘fovea’ hypotheses in the mouse

January 5, 2018

What need could there be for either nearest-neighbor relationships or nonuniform distributions of receptor cells in the olfactory epithelium (OE)? In this podcast, Editor-in-Chief Bill Yates (University of Pittsburgh) talks with Professor David Coppola (Randolph-Macon College, Ashland, Virginia) about a recent article which provides a novel test of the longstanding “sorption hypothesis” and related "fovea hypothesis", which posit that physical properties of odors, such as volatility and water solubility, determine a spatial pattern of stimulation across the OE that could aid odor discrimination. Listen to learn about the empirical and computational methods used to test these hypotheses, and the results which partially undermined the hypotheses!

Tests of the sorption and olfactory "fovea" hypotheses in the mouse
David M. Coppola, Brittaney E. Ritchie, and Brent A. Craven
Journal of Neurophysiology, published online November 7, 2017. DOI: 10.1152/jn.00455.2017.

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Acetylcholine and the efferent vestibular system

December 11, 2017

The efferent vestibular system (EVS) has two effects on afferent activity: 1) increases background afferent discharge; and 2) decreases afferent sensitivity to rotational stimuli. What cellular mechanisms might contribute to these responses? In this podcast, Editor-in-Chief Bill Yates (University of Pittsburgh) talks with Lauren Poppi (University of Newcastle, Australia) and Alan Brichta (University of Newcastle, Australia) about their recent article in which they expore the hypothesis that "the reduction in afferent sensitivity was attributed, in part, to the activation of alpha9-containing nAChRs ( 9nAChRs) and small-conductance potassium channels (SK) in vestibular type II hair cells." Listen to learn about their methods, the results, and more!

ACh-induced hyperpolarization and decreased resistance in mammalian type II vestibular hair cells
Lauren Ashlee Poppi, Hessam Tabatabaee, Hannah Rose Drury, Phillip Jobling, Robert J Callister, Americo A. Migliaccio, Paivi M Jordan, Joseph Christopher Holt, Richard D Rabbitt, Rebecca Lim, and Alan Martin Brichta
Journal of Neurophysiology, published online November 14, 2017. DOI: 10.1152/jn.00030.2017.

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A case study on camptocormia

November 22, 2017

Can studying an individual patient with camptocormia reveal new information about the neural control of balance and posture? In this podcast, Editor-in-Chief Bill Yates (University of Pittsburgh) talks with Rebecca St. George (University of Tasmania) and Fay Horak (Oregon Health and Science University) about the very first "Case Study in Neuroscience" article published in the Journal of Neurophysiology. The authors completed a wide variety of tests and found that "the disorder in this case was due to a disruption in the automatic, tonic drive to the postural muscles and myogenic changes were secondary," which demonstrates a divergence in the neural control of balance and posture.

Case Studies in Neuroscience: A Dissociation of Balance and Posture Demonstrated by Camptocormia
Rebecca J. St George, Victor S. Gurfinkel, Jeff Kraakevik, John G. Nutt, Fay B. Horak
Journal of Neurophysiology, published online October 4, 2017. DOI: 10.1152/jn.00582.2017.

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Neural oscillations and phase-amplitude coupling in Parkinson’s disease

November 9, 2017

Oscillatory neural activity in different frequency bands and phase-amplitude coupling (PAC) are hypothesized to be biomarkers of Parkinson’s disease (PD). Might these activity features help explain PD motor dysfunction, and serve as viable targets for closed-loop deep brain stimulation (DBS)? In this podcast, Editor-in-Chief Bill Yates (University of Pittsburgh) talks with David Escobar Sanabria (Department of Neurology, University of Minnesota) and Luke Johnson (Department of Neurology, University of Minnesota) about a recent study which explored these questions. Their findings helped to characterize these biomarkers across various vigilance states, and to build a foundation for future therapeutic techniques.

Parkinsonism and vigilance: alteration in neural oscillatory activity and phase-amplitude coupling in the basal ganglia and motor cortex
David Escobar Sanabria, Luke A. Johnson, Shane D. Nebeck, Jianyu Zhang, Matthew D. Johnson, Kenneth B. Baker, Gregory F. Molnar, Jerrold L. Vitek
Journal of Neurophysiology, published online November 3, 2017. DOI: 10.1152/jn.00388.2017.

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A frequency-dependent dual role for Aβ afferents during dynamic mechanical allodynia

October 30, 2017

It is thought that myelinated primary afferent fibers switch modality from light touch to pain following injury, which is referred to as dynamic mechanical allodynia (DMA). However, do the firing rates of Aβ afferents affect the intensity of perceived pain during DMA? In this podcast, Editor-in-Chief Bill Yates (University of Pittsburgh) talks with Line Loken (UCSF) about a recent study which explored this question. Surprisingly, following capsaicin-induced DMA there was an inverse relationship between Aβ firing rates and unpleasantness, such that brush stimuli that produced low firing rates were most painful and those that elicited high firing rates were rated as pleasant.

Low-threshold mechanoreceptors play a frequency-dependent, dual role in subjective ratings of mechanical allodynia
Line Sofie Loken, Eugene Duff, Irene Tracey
Journal of Neurophysiology, published online September 27, 2017. DOI: 10.1152/jn.00977.2016.

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Early psychosocial neglect and developing brain networks

October 16, 2017

What effects do early psychosocial neglect and institutional rearing have on developing brain networks? In this podcast, Editor-in-Chief Bill Yates (University of Pittsburgh) talks with Caterina Stamoulis (Harvard Medical School and Boston Children's Hospital) about findings from the Bucharest Early Intervention Project (BEIP). Researchers demonstrated aberrantly connected task-independent brain networks in children that had been raised in Romanian institutions. These findings have profound implicaitons about the developmental and cognitive effects of early institutionalization.

Neuronal networks in the developing brain are adversely modulated by early psychosocial neglect
Catherine Stamoulis, Ross E. Vanderwert, Charles H. Zeanah, Nathan A. Fox, Charles A. Nelson
Journal of Neurophysiology, published online October 5, 2017. DOI: 10.1152/jn.00014.2017.

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Multiple Sclerosis and Reduced Somatosensory Gating

September 26, 2017

Recently, sensory gating in the somatosensory system has been linked to deficits in tactile discrimination, which in turn has been linked to impaired walking and balance in individuals with multiple sclerosis (MS). In this podcast, Editor-in-Chief Bill Yates (University of Pittsburgh) talks with Dave Arpin (University of Louisville) about a new study which sought to examine the neural basis of somatosensory gating and to assess the relationship between somatosensory gating and walking performance in patients with MS and healthy controls.

A reduced somatosensory gating response in individuals with multiple sclerosis is related to walking impairment
David J. Arpin, James E. Gehringer, Tony W. Wilson, Max J. Kurz
Journal of Neurophysiology, published online July 19, 2017. DOI: 10.1152/jn.00260.2017.

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Caffeine accelerates emergence from anesthesia

September 13, 2017

There is currently no reliable reversal agent for general anesthesia. However, recent work has shown that three drugs that elevate intracellular cAMP (forskolin, theophylline, and caffeine) accelerate emergence from anesthesia in rats. In this podcast, Editor-in-Chief Bill Yates (University of Pittsburgh) talks with Jimmy Xie, Robert Fong, and Aaron Fox (all from the University of Chicago) about a new study that shows that caffeine is effective even at high levels of anesthetic, and which explores the mechanisms underlying this finding.

Caffeine accelerates recovery from general anesthesia via multiple pathways
Robert Fong, Suhail Khokhar, Atif N. Chowdhury, Kelvin G. Xie, Josiah Hiu-Yuen Wong, Aaron P. Fox, Zheng Xie
Journal of Neurophysiology, published online September 1, 2017. DOI: 10.1152/jn.00393.2017.

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