Read by QxMD icon Read

Journal of Neurophysiology

Amir-Mohammad Alizadeh, Ilse C Van Dromme, Peter Janssen
Both dorsal and ventral visual pathways harbor several areas sensitive to gradients of binocular disparity (i.e. higher-order disparity). While a wealth of information exists about disparity processing in early visual areas (V1, V2, and V3) as well as in end-stage areas TE in the ventral stream and the Anterior Intraparietal area (AIP) in the dorsal stream, little is known about mid-level area TEO in the ventral pathway. We recorded single unit responses to disparity-defined curved stimuli in a functional Magnetic Resonance Imaging (fMRI) activation elicited by curved surfaces compared to flat surfaces in the macaque area TEO...
September 19, 2018: Journal of Neurophysiology
Rodolfo Souza de Faria, Álvaro Luiz Bianchim Bereta, Guilherme Henrique Teixeira Reis, Lourdes Bethania Braga Dos Santos, Marcela Dos Santos Gomes Pereira, Paulo Oliveira Cortez, Elayne Vieira Dias, Dalmo Antonio Ribeiro Moreira, Clarissa Trzesniak, Cesar Renato Sartori
We investigated the relation between swimming exercise and fear memory extinction. Rats that performed regular swimming exercise over six weeks underwent a fear conditioning. Twenty-eight days later, they were submitted to extinction tests. Swimming rats had enhanced extinction process throughout the 5 days of the extinction test when compared to sedentary ones (Exercise vs. Fear Conditioning vs. Test days interaction effect. This suggests that the swimming exercise accelerated the process of aversive memory extinction, reducing the expression of conditioned fear behavior...
September 19, 2018: Journal of Neurophysiology
Joseph L Demer, Robert A Clark
We employed magnetic resonance imaging (MRI) to quantify human extraocular muscle contractility during centered target fusion, and fusional divergence repeated with each eye viewing monocularly at 20 cm through 8Δ, and at 400 cm through 4Δ base in prism. Contractility, indicated by posterior partial volume (PPV) change, was analyzed in transverse rectus and in medial and lateral superior oblique (SO) muscle compartments, and by cross sectional area change in the inferior oblique (IO). At 20 cm, 3.1±0.5° (SEM) diverging eye abduction in 10 subjects was associated with 4...
September 19, 2018: Journal of Neurophysiology
Heather R McGregor, Joshua G A Cashaback, Paul L Gribble
Action observation activates brain regions involved in sensory-motor control. Recent research has shown that action observation can also facilitate motor learning; observing a tutor undergoing motor learning results in functional plasticity within the motor system and gains in subsequent motor performance. However, the effects of observing motor learning extend beyond the motor domain. Converging evidence suggests that observation also results in somatosensory functional plasticity and somatosensory perceptual changes...
September 19, 2018: Journal of Neurophysiology
Samira Anderson, Robert Morris Ellis, Julie Mehta, Matthew J Goupell
The effects of aging and stimulus configuration on binaural masking level differences (BMLDs) were measured behaviorally and electrophysiologically, using the frequency-following response (FFR) to target brainstem/midbrain encoding. The tests were performed in 15 younger normal-hearing (YNH; <30 yrs) and 15 older normal-hearing (ONH; >60 yrs) participants. The stimuli consisted of a 500-Hz target tone embedded in a narrowband (50-Hz bandwidth) or wideband (1500-Hz bandwidth) noise masker. The interaural phase conditions included NoSo (tone and noise presented interaurally in-phase), NoSπ (noise presented interaurally in-phase and tone presented out-of-phase), and NπSo (noise presented interaurally out-of-phase and tone presented in-phase) configurations...
September 19, 2018: Journal of Neurophysiology
Menahem Segal
Extracellular calcium ions support synaptic activity, but also reduce excitability of central neurons. In the present study, the effect of calcium on excitability was explored in cultured hippocampal neurons. CaCl2 injected by pressure in the vicinity of a neuron that is bathed only in MgCl2 as the main divalent cation, caused a depolarizing shift in action potential threshold and a reduction in excitability. This effect was not seen if the intracellular milieu consisted of Cs+ instead of K-gluconate as the main cation, or when it contained ruthenium red, which blocks release of calcium from stores...
September 19, 2018: Journal of Neurophysiology
Raphael Schween, Jordan A Taylor, Mathias Hegele
The human ability to use different tools demonstrates our capability of forming and maintaining multiple, context specific motor memories. Experimentally, this has been investigated in dual adaptation, where participants adjust their reaching movements to opposing visuomotor transformations. Adaptation in these paradigms occurs by distinct processes, such as strategies for each transformation or the implicit acquisition of distinct visuomotor mappings. While distinct, transformation-dependent aftereffects have been interpreted as support for the latter, they could reflect adaptation of a single visuomotor map, which is locally adjusted in different regions of the workspace...
September 19, 2018: Journal of Neurophysiology
Lyndon J Smith, Lucy Norcliffe-Kaufmann, Jose-Alberto Palma, Horacio Kaufmann, Vaughan G Macefield
Patients with Hereditary Sensory & Autonomic Neuropathy type III exhibit marked ataxia, including gait disturbances. We recently showed that functional muscle spindle afferents in the leg, recorded via intraneural microelectrodes inserted into the peroneal nerve, are absent in HSAN III, although large-diameter cutaneous afferents are intact. Moreover, there is a tight correlation between loss of proprioceptive acuity at the knee and the severity of gait impairment. We tested the hypothesis that manual motor performance is also compromised in HSAN III, attributed to the predicted absence of muscle spindles in the intrinsic muscles of the hand...
September 19, 2018: Journal of Neurophysiology
Wan Jiang, Francois Tremblay, C Elaine Chapman
Caudal primary motor cortex (M1, area 4) is sensitive to cutaneous inputs but the extent to which the physical details of complex stimuli are encoded is not known. We investigated the sensitivity of M1 neurones (4 Macaca mulatta monkeys) to textured stimuli (smooth/rough or rough/rougher) during the performance of a texture discrimination task and, for some cells, during a No task condition (same surfaces; no response). The recordings were made from the hemisphere contralateral to the stimulated digits; the motor response (sensory decision) was made with the non stimulated arm...
September 12, 2018: Journal of Neurophysiology
Rui Zhou, Behdad Parhizi, Jennifer Assh, Laura Alvarado, Robert Ogilvie, Su Ling Chong, Vivian K Mushahwar
Spinal networks in the cervical and lumbar cord are actively coupled during locomotion to coordinate arm and leg activity. The goals of this project were to investigate the intersegmental cervico-lumbar connectivity during cycling after incomplete spinal cord injury (iSCI), and assess the effect of rehabilitation training on improving reflex modulation mediated by cervico-lumbar pathways. Two studies were conducted. In the first, 22 neurologically intact (NI) people and 10 people with chronic iSCI were recruited...
September 12, 2018: Journal of Neurophysiology
Ethan M Meyers
For over 45 years, neuroscientists have conducted experiments aimed at understanding the neural basis of working memory. Early results examining individual neurons highlighted that information is stored in working memory in persistent sustained activity where neurons maintained elevated firing rates over extended periods of time. However, more recent work has emphasized that information is often stored in working memory in dynamic population codes, where different neurons contain information at different periods in time...
September 12, 2018: Journal of Neurophysiology
Sarah A Hutter, Jordan A Taylor
It has become increasingly clear that learning in visuomotor rotation tasks, which induce an angular mismatch between movements of the hand and visual feedback, largely results from the combined effort of two distinct processes: implicit motor adaptation and explicit re-aiming. However, it remains unclear how these two processes work together to produce trial-by-trial learning. Previous work has found that implicit motor adaptation operates automatically, regardless of task relevancy, and saturates for large errors...
September 12, 2018: Journal of Neurophysiology
Roland Diggelmann, Michele Fiscella, Andreas Hierlemann, Felix Franke
High-density microelectrode arrays (HD-MEAs) can be used to record extracellular action potentials from hundreds to thousands of neurons simultaneously. Efficient spike-sorters have to be developed to cope with such large data volumes. Most existing spike sorting methods for single electrodes or small multi-electrodes, however, suffer from the "curse of dimensionality", and cannot be directly applied to recordings with hundreds of electrodes. This holds particularly true for the standard reference spike sorting algorithm, principal-component-analysis-based feature extraction, followed by k-means or expectation maximization clustering, against which most spike-sorters are evaluated...
September 12, 2018: Journal of Neurophysiology
Aiko K Thompson, Rachel Cote, Janice Sniffen, Jodi A Brangaccio
The activity of corticospinal pathways is important in movement control and its plasticity is essential for motor skill learning and re-learning after CNS injuries. Thus, enhancing the corticospinal function may improve motor function recovery after CNS injuries. Operant conditioning of stimulus-induced muscle responses (e.g., reflexes) is known to induce the targeted plasticity in a targeted pathway. Thus, an operant conditioning protocol to target the corticospinal pathways may be able to enhance the corticospinal function...
September 12, 2018: Journal of Neurophysiology
Lei Zhang, Anatol G Feldman, Mindy F Levin
Body orientation with respect to the direction of gravity changes when we lean forward from upright standing. We tested the hypothesis that during upright standing, the nervous system specifies the referent body orientation that defines spatial thresholds for activation of multiple muscles across the body. To intentionally lean the body forward, the system is postulated to transfer balance and stability to the leaned position by monotonically tilting the referent orientation, thus increasing the activation thresholds of ankle extensors and decreasing their activity...
September 12, 2018: Journal of Neurophysiology
MinHyuk Kwon, Evangelos A Christou
Currently, there is no evidence that magnification of visual feedback has motor implications beyond impairments in force control during a visuomotor task. We hypothesized that magnification of visual feedback would increase visual information processing, alter the muscle activation, and exacerbate the response time in older adults. To test this hypothesis, we examined whether magnification of visual feedback during a reaction time task alters the pre-motor time and the motor unit pool activation of older adults...
September 12, 2018: Journal of Neurophysiology
Moriah Hanson, Maura Concialdi
Motor imagery (MI) is a promising rehabilitation technique that has received significant interest for use in persons with multiple sclerosis (MS). Through alterations in neural networks, MI has the potential to improve measures of walking speed, walking distance, and fatigue in people with MS. Further research is required to assess the validity of MI in conjunction with other therapeutic MS treatments and provide objective outcome measures of motor improvements.
September 12, 2018: Journal of Neurophysiology
DeNard V Simmons, Matthew Henry Higgs, Sharmon Lebby, Charles J Wilson
The changes in firing probability produced by a synaptic input are usually visualized using the post-stimulus time histogram (PSTH). It would be useful if postsynaptic firing patterns could be predicted from patterns of afferent synaptic activation, but attempts to predict the PSTH from synaptic potential waveforms using reasoning based on voltage trajectory and spike threshold have not been successful, especially for inhibitory inputs. We measured PSTHs for substantia nigra pars reticulata (SNr) neurons inhibited by optogenetic stimulation of striato-nigral inputs, or by matching artificial inhibitory conductances applied by dynamic clamp...
September 12, 2018: Journal of Neurophysiology
Alain Guillaume, Jason R Fuller, Riju Srimal, Clayton E Curtis
Saccade adaptation is the learning process that ensures that vision and saccades remain calibrated. The central nervous system network involved in these adaptive processes remains unclear, due to difficulties isolating the learning process from the correlated visual and motor processes. Here, we imaged the human brain during a novel saccade adaptation paradigm that allowed us to isolate neural signals involved in learning independent of the changes in the amplitude of corrective saccades usually correlated with adaptation...
September 12, 2018: Journal of Neurophysiology
Alberto Lazari, Sigrid Koudelka, Cassandra Sampaio-Baptista
The production of new myelin has been highlighted as an underappreciated mechanism of brain plasticity, but whether plastic decreases in myelin also happen in the adult brain is largely unexplored. Recently, Sinclair et al. (Sinclair JS, Fischl MJ, Alexandrova O, Heß M, Grothe B, Leibold C, and Kopp-Scheinpflug C J Neurosci 37(34):8239 - 8255, 2017) have shown that auditory deprivation can lead to myelin and axonal reductions even in healthy adulthood. These findings show that activity-regulated myelination is more complex than previously thought, and expand our knowledge of how adult brain plasticity could operate on a the cellular level...
September 12, 2018: Journal of Neurophysiology
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"