Diverse effects of stimulus history in waking mouse auditory cortex
Responses to auditory stimuli are often strongly influenced by recent stimulus history. For example, in a paradigm called forward suppression, brief sounds can suppress the perception of, and the neural responses to, a subsequent sound, with the magnitude of this suppression depending on both the spectral and temporal distances between the sounds. As a step towards understanding the mechanisms that generate these adaptive representations in awake animals, we quantitatively characterize responses to two-tone sequences in the auditory cortex of waking mice. We find that cortical responses in a forward suppression paradigm ar...
Source: Journal of Neurophysiology - August 14, 2017 Category: Neurology Authors: Phillips, E. A. K., Schreiner, C. E., Hasenstaub, A. R. Tags: Research Articles Source Type: research
Activity of primate V1 neurons during the gap saccade task
When a saccadic eye movement is made toward a visual stimulus, the variability in accompanying primary visual cortex (V1) activity is related to saccade latency in both humans and simians. To understand the nature of this relationship, we examined the functional link between V1 activity and the initiation of visually guided saccades during the gap saccade task, in which a brief temporal gap is inserted between the turning off of a fixation stimulus and the appearance of a saccadic target. The insertion of such a gap robustly reduces saccade latency and facilitates the occurrence of extremely short-latency (express) saccade...
Source: Journal of Neurophysiology - August 14, 2017 Category: Neurology Authors: Kim, K., Lee, C. Tags: Research Articles Source Type: research
Excitability and firing behavior of single slow motor axons transmitting natural repetitive firing of human motoneurons
In conclusion, the present approach, exploring, for the first time, excitability recovery in single slow axons during motoneuron natural activation, can provide further insight into axonal firing behavior in normal states and diseases.
NEW & NOTEWORTHY Excitability of single slow axons was estimated by motor unit firing index in response to motor nerve stimulation, and its changes throughout a target interspike interval were explored during transmitting human motoneuron natural firing. It was found that axons exhibited early irresponsive, responsive, and later irresponsive periods. Findings question whether the traditi...
Source: Journal of Neurophysiology - August 14, 2017 Category: Neurology Authors: Kudina, L. P., Andreeva, R. E. Tags: Research Articles Source Type: research
Diffusion-weighted tractography in the common marmoset monkey at 9.4T
The common marmoset (Callithrix jacchus) is a small New World primate that is becoming increasingly popular in the neurosciences as an animal model of preclinical human disease. With several major disorders characterized by alterations in neural white matter (e.g., multiple sclerosis, Alzheimer’s disease, schizophrenia), proposed to be transgenically modeled using marmosets, the ability to isolate and characterize reliably major white matter fiber tracts with MRI will be of use for evaluating structural brain changes related to disease processes and symptomatology. Here, we propose protocols for isolating major white...
Source: Journal of Neurophysiology - August 14, 2017 Category: Neurology Authors: Schaeffer, D. J., Adam, R., Gilbert, K. M., Gati, J. S., Li, A. X., Menon, R. S., Everling, S. Tags: Research Articles Source Type: research
Physiological properties of brain-machine interface input signals
Brain-machine interfaces (BMIs), also called brain-computer interfaces (BCIs), decode neural signals and use them to control some type of external device. Despite many experimental successes and terrific demonstrations in animals and humans, a high-performance, clinically viable device has not yet been developed for widespread usage. There are many factors that impact clinical viability and BMI performance. Arguably, the first of these is the selection of brain signals used to control BMIs. In this review, we summarize the physiological characteristics and performance—including movement-related information, longevity...
Source: Journal of Neurophysiology - August 14, 2017 Category: Neurology Authors: Slutzky, M. W., Flint, R. D. Tags: Reviews Source Type: research
Accumulation of methylglyoxal increases the advanced glycation end-product levels in DRG and contributes to lumbar disk herniation-induced persistent pain
Lumbar disk herniation (LDH) with discogenic low back pain and sciatica is a common and complicated musculoskeletal disorder. The underlying mechanisms are poorly understood, and there are no effective therapies for LDH-induced pain. In the present study, we found that the patients who suffered from LDH-induced pain had elevated plasma methylglyoxal (MG) levels. In rats, implantation of autologous nucleus pulposus (NP) to the left lumbar 5 spinal nerve root, which mimicked LDH, induced mechanical allodynia, increased MG level in plasma and dorsal root ganglion (DRG), and enhanced the excitability of small DRG neurons (<...
Source: Journal of Neurophysiology - August 14, 2017 Category: Neurology Authors: Liu, C.-C., Zhang, X.-S., Ruan, Y.-T., Huang, Z.-X., Zhang, S.-B., Liu, M., Luo, H.-J., Wu, S.-L., Ma, C. Tags: Research Articles Source Type: research
Trajectory curvature in saccade sequences: spatiotopic influences vs. residual motor activity
When decisions drive saccadic eye movements, traces of the decision process can be inferred from the movement trajectories. For example, saccades can curve away from distractor stimuli, which was thought to reflect cortical inhibition biasing activity in the superior colliculus. Recent neurophysiological work does not support this theory, and two recent models have replaced top-down inhibition with lateral interactions in the superior colliculus or neural fatigue in the brainstem saccadic burst generator. All current models operate in retinotopic coordinates and are based on single saccade paradigms. To extend these models...
Source: Journal of Neurophysiology - August 14, 2017 Category: Neurology Authors: Megardon, G., Ludwig, C., Sumner, P. Tags: Research Articles Source Type: research
Neurophysiology and neural engineering: a review
Neurophysiology is the branch of physiology concerned with understanding the function of neural systems. Neural engineering (also known as neuroengineering) is a discipline within biomedical engineering that uses engineering techniques to understand, repair, replace, enhance, or otherwise exploit the properties and functions of neural systems. In most cases neural engineering involves the development of an interface between electronic devices and living neural tissue. This review describes the origins of neural engineering, the explosive development of methods and devices commencing in the late 1950s, and the present-day d...
Source: Journal of Neurophysiology - August 14, 2017 Category: Neurology Authors: Prochazka, A. Tags: Reviews Source Type: research
Mesoscale-duration activated states gate spiking in response to fast rises in membrane voltage in the awake brain
Seconds-scale network states, affecting many neurons within a network, modulate neural activity by complementing fast integration of neuron-specific inputs that arrive in the milliseconds before spiking. Nonrhythmic subthreshold dynamics at intermediate timescales, however, are less well characterized. We found, using automated whole cell patch clamping in vivo, that spikes recorded in CA1 and barrel cortex in awake mice are often preceded not only by monotonic voltage rises lasting milliseconds but also by more gradual (lasting tens to hundreds of milliseconds) depolarizations. The latter exert a gating function on spikin...
Source: Journal of Neurophysiology - August 14, 2017 Category: Neurology Authors: Singer, A. C., Talei Franzesi, G., Kodandaramaiah, S. B., Flores, F. J., Cohen, J. D., Lee, A. K., Borgers, C., Forest, C. R., Kopell, N. J., Boyden, E. S. Tags: Research Articles Source Type: research
Adaptation modulates correlated subthreshold response variability in visual cortex
Cortical sensory responses are highly variable across stimulus presentations. This variability can be correlated across neurons (due to some combination of dense intracortical connectivity, cortical activity level, and cortical state), with fundamental implications for population coding. Yet the interpretation of correlated response variability (or "noise correlation") has remained fraught with difficulty, in part because of the restriction to extracellular neuronal spike recordings. Here, we measured response variability and its correlation at the most microscopic level of electrical neural activity, the membrane potentia...
Source: Journal of Neurophysiology - August 7, 2017 Category: Neurology Authors: Wright, N. C., Hoseini, M. S., Wessel, R. Tags: Research Articles Source Type: research
Supramodal representation of temporal priors calibrates interval timing
Human timing behaviors are consistent with Bayesian inference, according to which both previous knowledge (prior) and current sensory information determine final responses. However, it is unclear whether the brain represents temporal priors exclusively for individual modalities or in a supramodal manner when temporal information comes from different modalities at different times. Here we asked participants to reproduce time intervals in either a unisensory or a multisensory context. In unisensory tasks, sample intervals drawn from a uniform distribution were presented in a single visual or auditory modality. In multisensor...
Source: Journal of Neurophysiology - August 7, 2017 Category: Neurology Authors: Zhang, H., Zhou, X. Tags: Research Articles Source Type: research
Functional connectivity between somatosensory and motor brain areas predicts individual differences in motor learning by observing
Action observation can facilitate the acquisition of novel motor skills; however, there is considerable individual variability in the extent to which observation promotes motor learning. Here we tested the hypothesis that individual differences in brain function or structure can predict subsequent observation-related gains in motor learning. Subjects underwent an anatomical MRI scan and resting-state fMRI scans to assess preobservation gray matter volume and preobservation resting-state functional connectivity (FC), respectively. On the following day, subjects observed a video of a tutor adapting her reaches to a novel for...
Source: Journal of Neurophysiology - August 7, 2017 Category: Neurology Authors: McGregor, H. R., Gribble, P. L. Tags: Research Articles Source Type: research
Spinal control of motor outputs by intrinsic and externally induced electric field potentials
Despite numerous studies on spinal neuronal systems, several issues regarding their role in motor behavior remain unresolved. One of these issues is how electric fields associated with the activity of spinal neurons influence the operation of spinal neuronal networks and how effects of these field potentials are combined with other means of modulating neuronal activity. Another closely related issue is how external electric field potentials affect spinal neurons and how they can be used for therapeutic purposes such as pain relief or recovery of motor functions by transspinal direct current stimulation. Nevertheless, progr...
Source: Journal of Neurophysiology - August 7, 2017 Category: Neurology Authors: Jankowska, E. Tags: Reviews Source Type: research
Long-lasting increase in axonal excitability after epidurally applied DC
Effects of direct current (DC) on nerve fibers have primarily been investigated during or just after DC application. However, locally applied cathodal DC was recently demonstrated to increase the excitability of intraspinal preterminal axonal branches for >1 h. The aim of this study was therefore to investigate whether DC evokes a similarly long-lasting increase in the excitability of myelinated axons within the dorsal columns. The excitability of dorsal column fibers stimulated epidurally was monitored by recording compound action potentials in peripheral nerves in acute experiments in deeply anesthetized rats. The res...
Source: Journal of Neurophysiology - August 7, 2017 Category: Neurology Authors: Jankowska, E., Kaczmarek, D., Bolzoni, F., Hammar, I. Tags: Research Articles Source Type: research
Fetal alcohol exposure reduces responsiveness of taste nerves and trigeminal chemosensory neurons to ethanol and its flavor components
Fetal alcohol exposure (FAE) leads to increased intake of ethanol in adolescent rats and humans. We asked whether these behavioral changes may be mediated in part by changes in responsiveness of the peripheral taste and oral trigeminal systems. We exposed the experimental rats to ethanol in utero by administering ethanol to dams through a liquid diet; we exposed the control rats to an isocaloric and isonutritive liquid diet. To assess taste responsiveness, we recorded responses of the chorda tympani (CT) and glossopharyngeal (GL) nerves to lingual stimulation with ethanol, quinine, sucrose, and NaCl. To assess trigeminal r...
Source: Journal of Neurophysiology - August 7, 2017 Category: Neurology Authors: Glendinning, J. I., Tang, J., Morales Allende, A. P., Bryant, B. P., Youngentob, L., Youngentob, S. L. Tags: Research Articles Source Type: research
