Wakefulness suppresses retinal wave-related neural activity in visual cortex
In the developing visual system before eye opening, spontaneous retinal waves trigger bursts of neural activity in downstream structures, including visual cortex. At the same ages when retinal waves provide the predominant input to the visual system, sleep is the predominant behavioral state. However, the interactions between behavioral state and retinal wave-driven activity have never been explicitly examined. Here we characterized unit activity in visual cortex during spontaneous sleep-wake cycles in 9- and 12-day-old rats. At both ages, cortical activity occurred in discrete rhythmic bursts, ~30–60 s apart, mirror...
Source: Journal of Neurophysiology - August 4, 2017 Category: Neurology Authors: Mukherjee, D., Yonk, A. J., Sokoloff, G., Blumberg, M. S. Tags: Research Articles Source Type: research
Control of the strength of visual-motor transmission as the mechanism of rapid adaptation of priors for Bayesian inference in smooth pursuit eye movements
Bayesian inference provides a cogent account of how the brain combines sensory information with "priors" based on past experience to guide many behaviors, including smooth pursuit eye movements. We now demonstrate very rapid adaptation of the pursuit system’s priors for target direction and speed. We go on to leverage that adaptation to outline possible neural mechanisms that could cause pursuit to show features consistent with Bayesian inference. Adaptation of the prior causes changes in the eye speed and direction at the initiation of pursuit. The adaptation appears after a single trial and accumulates over repeate...
Source: Journal of Neurophysiology - August 4, 2017 Category: Neurology Authors: Darlington, T. R., Tokiyama, S., Lisberger, S. G. Tags: Research Articles Source Type: research
Efferent inhibition strength is a physiological correlate of hyperacusis in children with autism spectrum disorder
Autism spectrum disorder (ASD) is a developmental disability that is poorly understood. ASD can influence communication, social interaction, and behavior. Children with ASD often have sensory hypersensitivities, including auditory hypersensitivity (hyperacusis). In adults with hyperacusis who are otherwise neurotypical, the medial olivocochlear (MOC) efferent reflex is stronger than usual. In children with ASD, the MOC reflex has been measured, but without also assessing hyperacusis. We assessed the MOC reflex in children with ASD by measuring the strength of MOC-induced inhibition of transient-evoked otoacoustic emissions...
Source: Journal of Neurophysiology - August 4, 2017 Category: Neurology Authors: Wilson, U. S., Sadler, K. M., Hancock, K. E., Guinan, J. J., Lichtenhan, J. T. Tags: Research Articles Source Type: research
Separable systems for recovery of finger strength and control after stroke
Impaired hand function after stroke is a major cause of long-term disability. We developed a novel paradigm that quantifies two critical aspects of hand function, strength, and independent control of fingers (individuation), and also removes any obligatory dependence between them. Hand recovery was tracked in 54 patients with hemiparesis over the first year after stroke. Most recovery of strength and individuation occurred within the first 3 mo. A novel time-invariant recovery function was identified: recovery of strength and individuation were tightly correlated up to a strength level of ~60% of estimated premorbid streng...
Source: Journal of Neurophysiology - August 4, 2017 Category: Neurology Authors: Xu, J., Ejaz, N., Hertler, B., Branscheidt, M., Widmer, M., Faria, A. V., Harran, M. D., Cortes, J. C., Kim, N., Celnik, P. A., Kitago, T., Luft, A. R., Krakauer, J. W., Diedrichsen, J. Tags: Research Articles Source Type: research
Robotic navigation to subcortical neural tissue for intracellular electrophysiology in vivo
In vivo studies of neurophysiology using the whole cell patch-clamp technique enable exquisite access to both intracellular dynamics and cytosol of cells in the living brain but are underrepresented in deep subcortical nuclei because of fouling of the sensitive electrode tip. We have developed an autonomous method to navigate electrodes around obstacles such as blood vessels after identifying them as a source of contamination during regional pipette localization (RPL) in vivo. In mice, robotic navigation prevented fouling of the electrode tip, increasing RPL success probability 3 mm below the pial surface to 82% (n = 72/88...
Source: Journal of Neurophysiology - August 4, 2017 Category: Neurology Authors: Stoy, W. A., Kolb, I., Holst, G. L., Liew, Y., Pala, A., Yang, B., Boyden, E. S., Stanley, G. B., Forest, C. R. Tags: Innovative Methodology Source Type: research
Development and aging of human spinal cord circuitries
The neural motor circuitries in the spinal cord receive information from our senses and the rest of the nervous system and translate it into purposeful movements, which allow us to interact with the rest of the world. In this review, we discuss how these circuitries are established during early development and the extent to which they are shaped according to the demands of the body that they control and the environment with which the body has to interact. We also discuss how aging processes and physiological changes in our body are reflected in adaptations of activity in the spinal cord motor circuitries. The complex, mult...
Source: Journal of Neurophysiology - August 4, 2017 Category: Neurology Authors: Geertsen, S. S., Willerslev-Olsen, M., Lorentzen, J., Nielsen, J. B. Tags: Reviews Source Type: research
Variations on a theme: species differences in synaptic connectivity do not predict central pattern generator activity
In this study we examined Si1 homologs in two additional nudibranchs: Flabellina iodinea, which evolved LR swimming independently of Melibe and Dendronotus, and Tritonia diomedea, which swims with dorsal-ventral (DV) body flexions. In Flabellina, the contralateral Si1s exhibit alternating rhythmic bursting activity during the SMP and are members of the swim central pattern generator (CPG), as in Melibe. The Si1 homologs in Tritonia do not burst rhythmically during the DV SMP but are inhibited and receive bilaterally synchronous synaptic input. In both Flabellina and Tritonia, the Si1 homologs exhibit reciprocal inhibition,...
Source: Journal of Neurophysiology - August 4, 2017 Category: Neurology Authors: Gunaratne, C. A., Sakurai, A., Katz, P. S. Tags: Research Articles Source Type: research
Automatic and intentional influences on saccade landing
Saccadic eye movements enable us to rapidly direct our high-resolution fovea onto relevant parts of the visual world. However, while we can intentionally select a location as a saccade target, the wider visual scene also influences our executed movements. In the presence of multiple objects, eye movements may be "captured" to the location of a distractor object, or be biased toward the intermediate position between objects (the "global effect"). Here we examined how the relative strengths of the global effect and visual object capture changed with saccade latency, the separation between visual items and stimulus contrast. ...
Source: Journal of Neurophysiology - August 4, 2017 Category: Neurology Authors: Aagten-Murphy, D., Bays, P. M. Tags: Research Articles Source Type: research
A balance of outward and linear inward ionic currents is required for generation of slow-wave oscillations
Regenerative inward currents help produce slow oscillations through a negative-slope conductance region of their current-voltage relationship that is well approximated by a linear negative conductance. We used dynamic-clamp injections of a linear current with such conductance, INL, to explore why some neurons can generate intrinsic slow oscillations whereas others cannot. We addressed this question in synaptically isolated neurons of the crab Cancer borealis after blocking action potentials. The pyloric network consists of a distinct pacemaker and follower neurons, all of which express the same complement of ionic currents...
Source: Journal of Neurophysiology - August 4, 2017 Category: Neurology Authors: Golowasch, J., Bose, A., Guan, Y., Salloum, D., Roeser, A., Nadim, F. Tags: Research Articles Source Type: research
Reevaluation of reflex responses of the human masseter muscle to electrical lip stimulation
This study examined the genuineness of these responses using both the classical analysis methods and the discharge rate method to uncover the realistic postsynaptic potentials in human trigeminal motor nucleus. Using the discharge rate method, we found that the electrical lip stimulation only generated a long-lasting single or compound inhibitory response that is followed by late, long-lasting excitation. These findings have important implications on the redrawing of the neuronal pathways of the trigeminal nerve that are frequently used to judge neuromuscular disorders of the trigeminal region.
NEW & NOTEWORTHY We exam...
Source: Journal of Neurophysiology - August 4, 2017 Category: Neurology Authors: Ugincius, P., Yilmaz, G., Sebik, O., Türker, K. S. Tags: Research Articles Source Type: research
Sodium pump regulation of locomotor control circuits
Sodium pumps are ubiquitously expressed membrane proteins that extrude three Na+ ions in exchange for two K+ ions, using ATP as an energy source. Recent studies have illuminated additional, dynamic roles for sodium pumps in regulating the excitability of neuronal networks in an activity-dependent fashion. We review their role in a novel form of short-term memory within rhythmic locomotor networks. The data we review derives mainly from recent studies on Xenopus tadpoles and neonatal mice. The role and underlying mechanisms of pump action broadly match previously published data from an invertebrate, the Drosophila larva. We...
Source: Journal of Neurophysiology - August 4, 2017 Category: Neurology Authors: Picton, L. D., Zhang, H., Sillar, K. T. Tags: Reviews Source Type: research
Inferring neuronal network functional connectivity with directed information
This study brings together the techniques of voltage-sensitive dye recording and information theory to infer the functional connectome of the feeding central pattern generating network of Aplysia. In contrast to current statistical approaches, the inference method developed in this study is data driven and validated by conductance-based model circuits, can distinguish excitatory and inhibitory connections, is robust against synaptic plasticity, and is capable of detecting network structures that mediate motor patterns. (Source: Journal of Neurophysiology)
Source: Journal of Neurophysiology - August 4, 2017 Category: Neurology Authors: Cai, Z., Neveu, C. L., Baxter, D. A., Byrne, J. H., Aazhang, B. Tags: Innovative Methodology Source Type: research
Background noise exerts diverse effects on the cortical encoding of foreground sounds
In natural listening conditions, many sounds must be detected and identified in the context of competing sound sources, which function as background noise. Traditionally, noise is thought to degrade the cortical representation of sounds by suppressing responses and increasing response variability. However, recent studies of neural network models and brain slices have shown that background synaptic noise can improve the detection of signals. Because acoustic noise affects the synaptic background activity of cortical networks, it may improve the cortical responses to signals. We used spike train decoding techniques to determ...
Source: Journal of Neurophysiology - August 4, 2017 Category: Neurology Authors: Malone, B. J., Heiser, M. A., Beitel, R. E., Schreiner, C. E. Tags: Research Articles Source Type: research
Split-arm swinging: the effect of arm swinging manipulation on interlimb coordination during walking
The objective of the present study is to explore the influence of arm swinging (AS) on BCG. Sixteen young, healthy individuals (eight women; eight right motor-dominant, eight left-motor dominant) participated. Participants performed 10 walking trials (2 min). In each of the trials AS was unilaterally manipulated (e.g., arm restriction, weight on the wrist), bilaterally manipulated, or not manipulated. The order of trials was random. Walking trials were performed on a treadmill. Gait kinematics were recorded by a motion capture system. Using feedback-controlled belt speed allowed the participants to walk at a self-determine...
Source: Journal of Neurophysiology - August 4, 2017 Category: Neurology Authors: Bondi, M., Zeilig, G., Bloch, A., Fasano, A., Plotnik, M. Tags: Research Articles Source Type: research
Auditory fear conditioning modifies steady-state evoked potentials in the rat inferior colliculus
The rat inferior colliculus (IC) is a major midbrain relay for ascending inputs from the auditory brain stem and has been suggested to play a key role in the processing of aversive sounds. Previous studies have demonstrated that auditory fear conditioning (AFC) potentiates transient responses to brief tones in the IC, but it remains unexplored whether AFC modifies responses to sustained periodic acoustic stimulation—a type of response called the steady-state evoked potential (SSEP). Here we used an amplitude-modulated tone—a 10-kHz tone with a sinusoidal amplitude modulation of 53.7 Hz—as the conditioning...
Source: Journal of Neurophysiology - August 4, 2017 Category: Neurology Authors: Lockmann, A. L. V., Mourao, F. A. G., Moraes, M. F. D. Tags: Research Articles Source Type: research
