Intended arm use influences interhemispheric correlation of {beta}-oscillations in primate medial motor areas
To investigate the role of interhemispheric β-synchronization in the selection of motor effectors, we trained two monkeys to memorize and perform multiple two-movement sequences that included unimanual repetition and bimanual switching. We recorded local field potentials simultaneously in the bilateral supplementary motor area (SMA) and pre-SMA to examine how the β-power in both hemispheres and the interhemispheric relationship of β-oscillations depend on the prepared sequence of arm use. We found a significant ipsilateral enhancement of β-power for bimanual switching trials in the left hemisphere and a...
Source: Journal of Neurophysiology - November 9, 2017 Category: Neurology Authors: Nakajima, T., Arisawa, H., Hosaka, R., Mushiake, H. Tags: Research Articles Source Type: research
Intrinsic frequency biases and profiles across human cortex
In this study we investigate in humans if regions may be biased toward particular frequencies of intrinsic activity and if a full cortical mapping still reveals an organization that follows this hierarchy. We examined the spectral power in multiple frequency bands (0.5–150 Hz) from task-independent data using magnetoencephalography (MEG). We compared standardized power across bands to find regional frequency biases. Our results demonstrate a mix of lower and higher frequency biases across sensory and higher order regions. Thus they suggest a more complex cortical organization that does not simply follow this hierarch...
Source: Journal of Neurophysiology - November 9, 2017 Category: Neurology Authors: Mellem, M. S., Wohltjen, S., Gotts, S. J., Ghuman, A. S., Martin, A. Tags: Research Articles Source Type: research
A role for the cystic fibrosis transmembrane conductance regulator in the nitric oxide-dependent release of Cl- from acidic organelles in amacrine cells
In this study, we test the hypothesis that the cystic fibrosis transmembrane conductance regulator (CFTR) is involved in the NO-dependent efflux of organellar Cl–. We first establish the mRNA and protein expression of CFTR in our model system, cultured chick retinal amacrine cells. Using whole cell voltage-clamp recordings of currents through GABA-gated Cl– channels, we examine the effects of pharmacological inhibition of CFTR on the NO-dependent release of internal Cl–. To interfere with the expression of CFTR, we used clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 genome editing...
Source: Journal of Neurophysiology - November 9, 2017 Category: Neurology Authors: Krishnan, V., Maddox, J. W., Rodriguez, T., Gleason, E. Tags: Research Articles Source Type: research
Functional and molecular plasticity of {gamma} and {alpha}1 GABAA receptor subunits in the dorsal motor nucleus of the vagus after experimentally induced diabetes
This study investigated the effect of chronic hyperglycemia/hypoinsulinemia on α1- and -subunit-specific GABAA receptor-mediated inhibition using electrophysiological recordings in vitro and quantitative RT-PCR. DMV neurons from streptozotocin-treated mice demonstrated enhancement of both phasic and tonic inhibitory currents in response to application of the α1-subunit-selective GABAA receptor-positive allosteric modulator zolpidem. Responses to low concentrations of the GABAA receptor antagonist gabazine suggested an additional increased contribution of -subunit-containing receptors to tonic currents in DMV ne...
Source: Journal of Neurophysiology - November 9, 2017 Category: Neurology Authors: Boychuk, C. R., Smith, K. C., Smith, B. N. Tags: Research Articles Source Type: research
Asymmetric vestibular stimulation reveals persistent disruption of motion perception in unilateral vestibular lesions
Self-motion perception was studied in patients with unilateral vestibular lesions (UVL) due to acute vestibular neuritis at 1 wk and 4, 8, and 12 mo after the acute episode. We assessed vestibularly mediated self-motion perception by measuring the error in reproducing the position of a remembered visual target at the end of four cycles of asymmetric whole-body rotation. The oscillatory stimulus consists of a slow (0.09 Hz) and a fast (0.38 Hz) half cycle. A large error was present in UVL patients when the slow half cycle was delivered toward the lesion side, but minimal toward the healthy side. This asymmetry diminished ov...
Source: Journal of Neurophysiology - November 9, 2017 Category: Neurology Authors: Panichi, R., Faralli, M., Bruni, R., Kiriakarely, A., Occhigrossi, C., Ferraresi, A., Bronstein, A. M., Pettorossi, V. E. Tags: Research Articles Source Type: research
State-dependent sensorimotor gating in a rhythmic motor system
In this study, we tested whether sensory feedback onto projection neurons is sensitive only to activation of a motor system, or also to the modulatory state underlying that activation, using the crab Cancer borealis stomatogastric nervous system. We examined how proprioceptor neurons (gastropyloric receptors, GPRs) influence the gastric mill (chewing) circuit neurons and the projection neurons (MCN1, CPN2) that drive the gastric mill rhythm. During gastric mill rhythms triggered by the mechanosensory ventral cardiac neurons (VCNs), GPR was shown previously to influence gastric mill circuit neurons, but its excitation of MC...
Source: Journal of Neurophysiology - November 9, 2017 Category: Neurology Authors: White, R. S., Spencer, R. M., Nusbaum, M. P., Blitz, D. M. Tags: Research Articles Source Type: research
Sequential hemifield gating of {alpha}- and {beta}-behavioral performance oscillations after microsaccades
Microsaccades are tiny saccades that occur during gaze fixation. Even though visual processing has been shown to be strongly modulated close to the time of microsaccades, both at central and peripheral eccentricities, it is not clear how these eye movements might influence longer term fluctuations in brain activity and behavior. Here we found that visual processing is significantly affected and, in a rhythmic manner, even several hundreds of milliseconds after a microsaccade. Human visual detection efficiency, as measured by reaction time, exhibited coherent rhythmic oscillations in the α- and β-frequency bands ...
Source: Journal of Neurophysiology - November 9, 2017 Category: Neurology Authors: Bellet, J., Chen, C.-Y., Hafed, Z. M. Tags: Research Articles Source Type: research
Tests of the sorption and olfactory "fovea" hypotheses in the mouse
The spatial distribution of receptors within sensory epithelia (e.g., retina and skin) is often markedly nonuniform to gain efficiency in information capture and neural processing. By contrast, odors, unlike visual and tactile stimuli, have no obvious spatial dimension. What need then could there be for either nearest-neighbor relationships or nonuniform distributions of receptor cells in the olfactory epithelium (OE)? Adrian (Adrian ED. J Physiol 100: 459–473, 1942; Adrian ED. Br Med Bull 6: 330–332, 1950) provided the only widely debated answer to this question when he posited that the physical properties of ...
Source: Journal of Neurophysiology - November 7, 2017 Category: Neurology Authors: Coppola, D. M., Ritchie, B. E., Craven, B. A. Tags: Research Articles Source Type: research
Method to remove photoreceptors from whole mount retina in vitro
This study reports a method for removing photoreceptors from rodent whole mount retina while preserving the architecture of the inner retina. The method enables easier access to the inner retina for studies of neural processing, such as by patch clamp recording. (Source: Journal of Neurophysiology)
Source: Journal of Neurophysiology - November 7, 2017 Category: Neurology Authors: Walston, S. T., Chang, Y.-C., Weiland, J. D., Chow, R. H. Tags: Innovative Methodology Source Type: research
Spinal BDNF-induced phrenic motor facilitation requires PKC{theta} activity
Spinal brain-derived neurotrophic factor (BDNF) is necessary and sufficient for certain forms of long-lasting phrenic motor facilitation (pMF). BDNF elicits pMF by binding to its high-affinity receptor, tropomyosin receptor kinase B (TrkB), on phrenic motor neurons, potentially activating multiple downstream signaling cascades. Canonical BDNF/TrkB signaling includes the 1) Ras/RAF/MEK/ERK MAP kinase, 2) phosphatidylinositol 3-kinase (PI3K)/Akt, and 3) PLC/PKC pathways. Here we demonstrate that spinal BDNF-induced pMF requires PLC/PKC in normal rats but not MEK/ERK or PI3K/Akt signaling. Cervical intrathecal injections of M...
Source: Journal of Neurophysiology - November 7, 2017 Category: Neurology Authors: Agosto-Marlin, I. M., Mitchell, G. S. Tags: Research Articles Source Type: research
Variance in exposed perturbations impairs retention of visuomotor adaptation
Sensorimotor control requires an accurate estimate of the state of the body. The brain optimizes state estimation by combining sensory signals with predictions of the sensory consequences of motor commands using a forward model. Given that both sensory signals and predictions are uncertain (i.e., noisy), the brain optimally weights the relative reliance on each source of information during adaptation. In support, it is known that uncertainty in the sensory predictions influences the rate and generalization of visuomotor adaptation. We investigated whether uncertainty in the sensory predictions affects the retention of a ne...
Source: Journal of Neurophysiology - November 7, 2017 Category: Neurology Authors: Canaveral, C. A., Danion, F., Berrigan, F., Bernier, P.-M. Tags: Research Articles Source Type: research
Hyperalgesia and sensitization of dorsal horn neurons following activation of NK-1 receptors in the rostral ventromedial medulla
Neurons in the rostral ventromedial medulla (RVM) project to the spinal cord and are involved in descending modulation of pain. Several studies have shown that activation of neurokinin-1 (NK-1) receptors in the RVM produces hyperalgesia, although the underlying mechanisms are not clear. In parallel studies, we compared behavioral measures of hyperalgesia to electrophysiological responses of nociceptive dorsal horn neurons produced by activation of NK-1 receptors in the RVM. Injection of the selective NK-1 receptor agonist Sar9,Met(O2)11-substance P (SSP) into the RVM produced dose-dependent mechanical and heat hyperalgesia...
Source: Journal of Neurophysiology - November 7, 2017 Category: Neurology Authors: Khasabov, S. G., Malecha, P., Noack, J., Tabakov, J., Giesler, G. J., Simone, D. A. Tags: Research Articles Source Type: research
Rapid visuomotor feedback gains are tuned to the task dynamics
Adaptation to novel dynamics requires learning a motor memory, or a new pattern of predictive feedforward motor commands. Recently, we demonstrated the upregulation of rapid visuomotor feedback gains early in curl force field learning, which decrease once a predictive motor memory is learned. However, even after learning is complete, these feedback gains are higher than those observed in the null field trials. Interestingly, these upregulated feedback gains in the curl field were not observed in a constant force field. Therefore, we suggest that adaptation also involves selectively tuning the feedback sensitivity of the se...
Source: Journal of Neurophysiology - November 3, 2017 Category: Neurology Authors: Franklin, S., Wolpert, D. M., Franklin, D. W. Tags: Research Articles Source Type: research
Intermittent apnea elicits inactivity-induced phrenic motor facilitation via a retinoic acid- and protein synthesis-dependent pathway
Respiratory motoneuron pools must provide rhythmic inspiratory drive that is robust and reliable, yet dynamic enough to respond to respiratory challenges. One form of plasticity that is hypothesized to contribute to motor output stability by sensing and responding to inadequate respiratory neural activity is inactivity-induced phrenic motor facilitation (iPMF), an increase in inspiratory output triggered by a reduction in phrenic synaptic inputs. Evidence suggests that mechanisms giving rise to iPMF differ depending on the pattern of reduced respiratory neural activity (i.e., neural apnea). A prolonged neural apnea elicits...
Source: Journal of Neurophysiology - November 3, 2017 Category: Neurology Authors: Baertsch, N. A., Baker, T. L. Tags: Research Articles Source Type: research
Muscle proprioceptors in adult rat: mechanosensory signaling and synapse distribution in spinal cord
This report presents the first findings detailing specializations in mechanosensory signaling and intraspinal targets for functionally identified subtypes of muscle proprioceptors in the rat. (Source: Journal of Neurophysiology)
Source: Journal of Neurophysiology - November 3, 2017 Category: Neurology Authors: Vincent, J. A., Gabriel, H. M., Deardorff, A. S., Nardelli, P., Fyffe, R. E. W., Burkholder, T., Cope, T. C. Tags: Research Articles Source Type: research
