Ube3a loss increases excitability and blunts orientation tuning in the visual cortex of Angelman syndrome model mice
Angelman syndrome (AS) is a neurodevelopmental disorder caused by loss of the maternally inherited allele of UBE3A. Ube3aSTOP/p+ mice recapitulate major features of AS in humans and allow conditional reinstatement of maternal Ube3a with the expression of Cre recombinase. We have recently shown that AS model mice exhibit reduced inhibitory drive onto layer (L)2/3 pyramidal neurons of visual cortex, which contributes to a synaptic excitatory/inhibitory imbalance. However, it remains unclear how this loss of inhibitory drive affects neural circuits in vivo. Here we examined visual cortical response properties in individual ne...
Source: Journal of Neurophysiology - July 14, 2017 Category: Neurology Authors: Wallace, M. L., van Woerden, G. M., Elgersma, Y., Smith, S. L., Philpot, B. D. Tags: Research Articles Source Type: research
Neuropeptide-Y alters VTA dopamine neuron activity through both pre- and postsynaptic mechanisms
The mesocorticolimbic dopamine system, the brain’s reward system, regulates many different behaviors including food intake, food reward, and feeding-related behaviors, and there is increasing evidence that hypothalamic feeding-related neuropeptides alter dopamine neuron activity to affect feeding. For example, neuropeptide-Y (NPY), a strong orexigenic hypothalamic neuropeptide, increases motivation for food when injected into the ventral tegmental area (VTA). How NPY affects the activity of VTA dopamine neurons to regulate feeding behavior is unknown, however. In these studies we have used whole cell patch-clamp elec...
Source: Journal of Neurophysiology - July 14, 2017 Category: Neurology Authors: West, K. S., Roseberry, A. G. Tags: Research Articles Source Type: research
Cl- channel is required for CXCL10-induced neuronal activation and itch response in a murine model of allergic contact dermatitis
This study revealed that CXCL10 evoked an ionic current mainly carried by Cl– channels. We suggest that Cl– channels are likely key molecular candidates responsible for the CXCL10-evoked neuronal activation and itch-like behaviors in a murine model of allergic contact dermatitis induced by the antigen squaric acid dibutylester. Cl– channels may emerge as a promising drug target for the treatment of allergic itch in which CXCL10/CXCR3 signaling may participate. (Source: Journal of Neurophysiology)
Source: Journal of Neurophysiology - July 14, 2017 Category: Neurology Authors: Qu, L., Fu, K., Shimada, S. G., LaMotte, R. H. Tags: Research Articles Source Type: research
Modulation of long-latency afferent inhibition by the amplitude of sensory afferent volley
This study investigated the relationship between LAI and the sensory nerve action potentials (SNAP) from the median nerve (MN) and the digital nerves (DN) of the second digit. LAI was obtained by delivering nerve stimulation 200 ms before a TMS pulse delivered over the motor cortex. Experiment 1 assessed the magnitude of LAI following stimulation of the contralateral MN or DN using nerve stimulus intensities relative to the maximum SNAP (SNAPmax) of that nerve and two TMS intensities (0.5- and 1-mV MEP). Results indicate that MN LAI is maximal at ~50% SNAPmax, when presumably all sensory afferents are recruited for TMS of ...
Source: Journal of Neurophysiology - July 14, 2017 Category: Neurology Authors: Turco, C. V., El-Sayes, J., Fassett, H. J., Chen, R., Nelson, A. J. Tags: Research Articles Source Type: research
Activation mechanism of a neuromodulator-gated pacemaker ionic current
We presently report that the activation mechanism depends on intracellular and extracellular calcium-sensitive components. (Source: Journal of Neurophysiology)
Source: Journal of Neurophysiology - July 14, 2017 Category: Neurology Authors: Gray, M., Daudelin, D. H., Golowasch, J. Tags: Research Articles Source Type: research
Magnitude and behavior of cross-talk effects in multichannel electrophysiology experiments
Modern neurophysiological experiments frequently involve multiple channels separated by very small distances. A unique methodological concern for multiple-electrode experiments is that of capacitive coupling (cross-talk) between channels. Yet the nature of the cross-talk recording circuit is not well known in the field, and the extent to which it practically affects neurophysiology experiments has never been fully investigated. Here we describe a simple electrical circuit model of simultaneous recording and stimulation with two or more channels and experimentally verify the model using ex vivo brain slice and in vivo whole...
Source: Journal of Neurophysiology - July 14, 2017 Category: Neurology Authors: Nelson, M. J., Valtcheva, S., Venance, L. Tags: Research Articles Source Type: research
Characterizing the effects of feature salience and top-down attention in the early visual system
We report additive effects of attention and bottom-up salience in early visual areas, suggesting that salience enhancement is not contingent on the observer’s attentional state. (Source: Journal of Neurophysiology)
Source: Journal of Neurophysiology - July 14, 2017 Category: Neurology Authors: Poltoratski, S., Ling, S., McCormack, D., Tong, F. Tags: Research Articles Source Type: research
Neural coding of time-varying interaural time differences and time-varying amplitude in the inferior colliculus
Binaural cues occurring in natural environments are frequently time varying, either from the motion of a sound source or through interactions between the cues produced by multiple sources. Yet, a broad understanding of how the auditory system processes dynamic binaural cues is still lacking. In the current study, we directly compared neural responses in the inferior colliculus (IC) of unanesthetized rabbits to broadband noise with time-varying interaural time differences (ITD) with responses to noise with sinusoidal amplitude modulation (SAM) over a wide range of modulation frequencies. On the basis of prior research, we h...
Source: Journal of Neurophysiology - July 14, 2017 Category: Neurology Authors: Zuk, N., Delgutte, B. Tags: Research Articles Source Type: research
Contributions of space-clamp errors to apparent time-dependent loss of Mg2+ block induced by NMDA
We report that upon sustained activation of NMDARs in juvenile mouse hippocampal neurons there is apparent loss of Mg2+ block at negative membrane potentials. However, the phenomenon is explained by loss of dendritic voltage clamp, leading to a linear current-voltage relationship. Our results give a specific example of how spatial voltage errors in voltage-clamp recordings can readily be misinterpreted as biological modulation. (Source: Journal of Neurophysiology)
Source: Journal of Neurophysiology - July 14, 2017 Category: Neurology Authors: Sun, M.-Y., Chisari, M., Eisenman, L. N., Zorumski, C. F., Mennerick, S. J. Tags: Research Articles Source Type: research
The potential for understanding the synaptic organization of human motor commands via the firing patterns of motoneurons
Motoneurons are unique in being the only neurons in the CNS whose firing patterns can be easily recorded in human subjects. This is because of the one-to-one relationship between the motoneuron and muscle cell behavior. It has long been appreciated that the connection of motoneurons to their muscle fibers allows their action potentials to be amplified and recorded, but only recently has it become possible to simultaneously record the firing pattern of many motoneurons via array electrodes placed on the skin. These firing patterns contain detailed information about the synaptic organization of motor commands to the motoneur...
Source: Journal of Neurophysiology - July 14, 2017 Category: Neurology Authors: Johnson, M. D., Thompson, C. K., Tysseling, V. M., Powers, R. K., Heckman, C. J. Tags: Reviews Source Type: research
Presynaptic and extrasynaptic regulation of posterior nucleus of thalamus
The posterior nucleus of thalamus (PO) is a higher-order nucleus involved in sensorimotor processing, including nociception. An important characteristic of PO is its wide range of activity profiles that vary across states of arousal, thought to underlie differences in somatosensory perception subject to attention and degree of consciousness. Furthermore, PO loses the ability to downregulate its activity level in some forms of chronic pain, suggesting that regulatory mechanisms underlying the normal modulation of PO activity may be pathologically altered. However, the mechanisms responsible for regulating such a wide dynami...
Source: Journal of Neurophysiology - July 14, 2017 Category: Neurology Authors: Park, A., Li, Y., Masri, R., Keller, A. Tags: Research Articles Source Type: research
Interaction of compass sensing and object-motion detection in the locust central complex
Goal-directed behavior is often complicated by unpredictable events, such as the appearance of a predator during directed locomotion. This situation requires adaptive responses like evasive maneuvers followed by subsequent reorientation and course correction. Here we study the possible neural underpinnings of such a situation in an insect, the desert locust. As in other insects, its sense of spatial orientation strongly relies on the central complex, a group of midline brain neuropils. The central complex houses sky compass cells that signal the polarization plane of skylight and thus indicate the animal’s steering d...
Source: Journal of Neurophysiology - July 14, 2017 Category: Neurology Authors: Bockhorst, T., Homberg, U. Tags: Research Articles Source Type: research
Brain negativity as an indicator of predictive error processing: the contribution of visual action effect monitoring
In this study, we are separating different kinds of possible contributors to an electroencephalogram (EEG) error correlate (Ne/ERN) in a throwing task. We tested the influence of action effect monitoring on the Ne/ERN amplitude in the EEG. We used a task that allows us to restrict movement correction and action effect monitoring and to control the onset of result feedback. We ascribe the Ne/ERN to predictive error processing where a conscious feeling of failure is not a prerequisite. (Source: Journal of Neurophysiology)
Source: Journal of Neurophysiology - July 11, 2017 Category: Neurology Authors: Joch, M., Hegele, M., Maurer, H., Müller, H., Maurer, L. K. Tags: Research Articles Source Type: research
Temporal integration and 1/f power scaling in a circuit model of cerebellar interneurons
In conclusion, stellate and basket cells in cerebellar cortex, and interneuron circuits in general, may not only provide fast inhibition to principal cells but also act as temporal integrators that build a very short-term memory.
NEW & NOTEWORTHY The most common function attributed to inhibitory interneurons is feedforward control of principal neurons. In many brain regions, however, the interneurons are densely interconnected via both chemical and electrical synapses but the function of this coupling is largely unknown. Based on large-scale simulations of an interneuron circuit of cerebellar cortex, we propose that th...
Source: Journal of Neurophysiology - July 11, 2017 Category: Neurology Authors: Maex, R., Gutkin, B. Tags: Research Articles Source Type: research
Muscle synergies obtained from comprehensive mapping of the primary motor cortex forelimb representation using high-frequency, long-duration ICMS
Simplifying neuromuscular control for movement has previously been explored by extracting muscle synergies from voluntary movement electromyography (EMG) patterns. The purpose of this study was to investigate muscle synergies represented in EMG recordings associated with direct electrical stimulation of single sites in primary motor cortex (M1). We applied single-electrode high-frequency, long-duration intracortical microstimulation (HFLD-ICMS) to the forelimb region of M1 in two rhesus macaques using parameters previously found to produce forelimb movements to stable spatial end points (90–150 Hz, 90–150 μA...
Source: Journal of Neurophysiology - July 11, 2017 Category: Neurology Authors: Amundsen Huffmaster, S. L., Van Acker, G. M., Luchies, C. W., Cheney, P. D. Tags: Research Articles Source Type: research
