Effects of Aging on Amplitude-Modulated Encoding in Primary Auditory Cortex

June 3, 2016

Temporal envelope processing is critical for speech comprehension, which is known to be affected by normal aging. While the macaque is an excellent animal model for human cerebral cortical function, few studies have investigated neural processing in the auditory cortex of aged non-human primates. In this podcast, Editor-in-Chief Bill Yates (University of Pittsburgh), Associate Editor Conny Kopp-Scheinpflug (Ludwig-Maximilians-Universität München), content expert Robert Frisina (University of South Florida) join lead author Jacqueline Overton (UC Davis Center for Neuroscience) in an engaging discussion about age-related changes in the spiking activity of neurons in primary auditory cortex of aged macaque monkeys. What is the role and importance of rate and temporal codes in representing dynamic auditory stimuli? Listen and find out.

Effects of aging on the response of single neurons to amplitude-modulated noise in primary auditory cortex of rhesus macaque
Jacqueline A. Overton, Gregg H. Recanzone
Journal of Neurophysiology, published June 3, 2016. DOI: 10.1152/jn.01098.2015.

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Neurophysiology of Tactile Perception

June 1, 2016

Listen as Jeff Yau (Baylor College of Medicine) describes his experience working with Steve Hsiao at Johns Hopkins University, summarizes his contribution to our collection of articles on the neurophysiology of tactile perception, and discusses the value of this collection for those involved in somatosensory research.

Read our collection of articles on the neurophysiology of tactile perception.

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Visual Ecology and Potassium Conductances of Insect Photoreceptors

May 25, 2016

Important insights into neurobiology are gained through comparisons of neural systems and processes across species. By understanding the differences between the nervous systems of animals in relation to their behavior and environmental challenges, we can ascertain how the nervous system integrates information and generates motor responses. In this podcast, Editor-in-Chief Bill Yates (University of Pittsburgh) and Associate Editor Patsy Dickinson (Bowdoin College) join lead author Roman Frolov (University of Oulu) in an enlightening discussion on the visual ecology and potassium conductances of photoreceptors in 15 species of various orders of insects characterized by highly variable lifestyles. What can the combination of electrophysiology and visual ecology tells us about Kv channel selection in insects? Listen and find out.

Visual ecology and potassium conductances of insect photoreceptors
Roman Frolov, Esa-Ville Immonen, Matti Weckström
Journal of Neurophysiology, published April 1, 2016. DOI: 10.1152/jn.00795.2015.

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Local and Global Contributions to Hemodynamic Activity in Mouse Cortex

May 17, 2016

Imaging techniques such as functional magnetic resonance imaging seek to estimate neural signals in local brain regions through measurements of hemodynamic activity, but what is the significance of the large vascular fluctuations that accompany this activity, and what impact do these fluctuations have on estimates of neural signals? In this podcast, Editor-in-Chief Bill Yates (University of Pittsburgh) and content expert Aniruddha Das (Columbia University College of Physicians and Surgeons) join authors Andrea Pisauro (University of Glasgow) and Matteo Carandini (University College London) in an engaging discussion about their use of optical imaging in visual cortex of awake mice to characterize these vascular fluctuations. Are these fluctuations just noise, or do they actually reflect variations in the brain state? Listen and find out.

Local and global contributions to hemodynamic activity in mouse cortex
M. Andrea Pisauro, Andrea Benucci, Matteo Carandini
Journal of Neurophysiology, published online March 16, 2016. DOI: 10.1152/jn.00125.2016.

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DREADD Activation of Subfornical Organ Neurons

May 10, 2016

Circumventricular organs are specialized brain nuclei that lack a complete blood-brain barrier. These areas contain specialized sensory neurons to detect substances in the circulation to subsequently alter brain function. One such region, the subfornical organ, plays a pivotal role in body fluid homeostasis and autonomic function including neurogenic forms of hypertension and cardiovascular disease. In this podcast, Editor-in-Chief Bill Yates (University of Pittsburgh) and guest expert Alastair Ferguson (Queen's University) join authors Sean Stocker (Penn State College of Medicine), Haley Nation (Penn State College of Medicine) and Brian Kinsman (Penn State College of Medicine) in an engaging discussion about their investigation into whether selective activation of subfornical organ neurons using virally-mediated expression of Designer Receptors Exclusively Activated by Designer Drugs, or DREADDs, stimulates thirst and salt appetite. Could neurons of the subfornical organ be a potential therapeutic target for the treatment of body fluid homeostatic disorders and cardiovascular disease? Listen and find out.

DREADD-induced activation of subfornical organ neurons stimulates thirst and salt appetite
Haley L. Nation, Marvin Nicoleau, Brian J. Kinsman, Kirsteen N. Browning, Sean D. Stocker
Journal of Neurophysiology, published online March 30, 2016. DOI: 10.1152/jn.00149.2016.

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Neurobiology of Deep Brain Stimulation

April 27, 2016

What is deep brain stimulation? How does it work? Listen as Editor-in-Chief Bill Yates (University of Pittsburgh) and neurosurgeon Dr. Mark Richardson (University of Pittsburgh) discuss this therapeutic technique that has been effective in treating Parkinson’s disease, essential tremor, dystonia, chronic pain, and other diseases. Dr. Richardson also provides some valuable insight into our collection of articles on research related to the neurobiology of deep brain stimulation.

Read our collection of articles on the neurobiology of deep brain stimulation. (Image source: DOI 10.1152/jn.00275.2015)

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Manifestation of Acoustic Trauma in the Auditory Cortex

April 25, 2016

Exposure to loud sounds damages the auditory periphery and induces maladaptive changes in central parts of the auditory system, but it is still unclear which types of inhibitory interneurons are affected by acoustic trauma. Novák and colleagues used single-unit electrophysiological recording and two-photon calcium imaging in anaesthetized mice to evaluate the effects of acute acoustic trauma on the response properties of neurons in the core auditory cortex. In this podcast, Editor-in-Chief Bill Yates (University of Pittsburgh), Associate Editor Conny Kopp-Scheinpflug (Ludwig-Maximilians-Universität München) and content expert Jason Middleton (Louisiana State University Health Sciences Center) join authors Josef Syka (Academy of Sciences of the Czech Republic) and Ondrej Novák (Academy of Sciences of the Czech Republic) in an engaging discussion about their recent study. Is there a selective layer-dependent impact of acute acoustic trauma on the activity of cortical interneurons? Listen and find out.

Immediate manifestation of acoustic trauma in the auditory cortex is layer-specific and cell type-dependent
Ondřej Novák, Ondřej Zelenka, Tomáš Hromádka, Josef Syka
Journal of Neurophysiology, published April 8, 2016. DOI: 10.1152/jn.00810.2015.

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Serotonergic Fluctuations in the Male Auditory Midbrain during Courtship

April 14, 2016

Cues from social partners activate socially responsive neuromodulatory systems, priming brain regions including sensory systems to process these cues appropriately. However, there has been little investigation of serotonergic fluctuations in sensory regions during ongoing social encounters. To address this issue, Sarah Keesom and Laura Hurley, both researchers at Indiana University, used voltammetry to monitor serotonergic fluctuations in an auditory midbrain nucleus, the inferior colliculus, of male mice (Mus musculus) paired with females, and concurrently measured behaviors of both social partners. In this podcast, Editor-in-Chief Bill Yates (University of Pittsburgh) and guest expert Luke Remage-Healey (University of Massachusetts Amherst) join authors Sarah and Laura in an engaging discussion about their recent work on whether serotonergic fluctuations in sensory regions reflect variation within a context like opposite-sex interaction. Could the serotonergic system be a mechanism by which the neurochemical environment of the auditory system is matched to the social milieu? Listen and find out.

Socially induced serotonergic fluctuations in the male auditory midbrain correlate with female behavior during courtship
Sarah M. Keesom, Laura M. Hurley
Journal of Neurophysiology, published April 5, 2016. DOI: 10.1152/jn.00742.2015.

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Ipsilateral Motor Evoked Potentials and Intracortical Inhibition

February 17, 2016

Seeking to better understand the role of ipsilateral primary motor cortex during functional motor tasks, Byblow and colleagues examined whether ipsilateral motor evoked potentials (iMEPs) in the biceps brachii would be suppressed by sub-threshold conditioning, thereby demonstrating short-interval intracortical inhibition of iMEPs. In this podcast, Editor-in-Chief Bill Yates (University of Pittsburgh) and Associate Editor Monica A. Perez (University of Miami) join authors Winston Byblow (University of Auckland) and Alana McCambridge (University of Auckland) in an engaging discussion about their recent work. Are ipsilateral motor evoked potentials subject to intracortical inhibition? Listen and find out.

Are ipsilateral motor evoked potentials subject to intracortical inhibition?
Alana B. McCambridge, James W. Stinear, Winston D. Byblow
Journal of Neurophysiology, published January 20, 2016. DOI: 10.1152/jn.01139.2015.

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Oculomotor Selection Underlies Feature Retention

January 22, 2016

With oculomotor selection, spatial task relevance and visual working memory highly intertwined and sustained by similar cortical structures, how is it possible to distinguish between oculomotor selection and spatial task relevance if task relevant locations always constitute potential saccade targets? Hanning and colleagues designed an experiment to dissociate in humans the contribution of task relevance, oculomotor selection and oculomotor execution to the retention of feature representations in working memory. In this podcast, Editor-in-Chief Bill Yates (University of Pittsburgh) and Associate Editors Christos Constantinidis (Wake Forest School of Medicine) and Michele Basso (University of California at Los Angeles) join authors Nina Hanning (Ludwig-Maximilians-Universität München) and Donatas Jonikaitis (Stanford University School of Medicine) in an engaging discussion about their recent work. Is there an overlapping neural circuitry serving saccade target selection and feature-based working memory that can be dissociated from processes encoding task relevant locations? Listen and find out.

Oculomotor selection underlies feature retention in visual working memory
Nina Maria Hanning, Donatas Jonikaitis, Heiner Deubel, Martin Szinte
Journal of Neurophysiology, published November 18, 2015. DOI: 10.1152/jn.00927.2015.

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