Journal of Neurophysiology

Montefinese, Maria

doi: 10.1152/jn.00065.2019pmid: 30785804

Evidence from both behavioral and neuropsychological studies suggest that different types of organizational principles govern semantic representations of abstract and concrete words. The reviewed neuroimaging studies provide new evidence about the role of brain areas of the semantic network involved in the encoding of some types of information during processing of abstract and concrete concepts, better characterizing the neural underpinnings and the organizational principles of semantic representation of these types of word.

Casartelli, Luca

doi: 10.1152/jn.00060.2019pmid: 30840541

Neural, oscillatory, and computational counterparts of multisensory processing remain a crucial challenge for neuroscientists. Converging evidence underlines a certain efficiency in balancing stability and flexibility of sensory sampling, supporting the general idea that multiple parallel and hierarchically organized processing stages in the brain contribute to our understanding of the (sensory/perceptual) world. Intriguingly, how temporal dynamics impact and modulate multisensory processes in our brain can be investigated benefiting from studies on perceptual illusions.

Lucas-Osma, Ana M.; Li, Yaqing; Murray, Katie; Lin, Shihao; Black, Sophie; Stephens, Marilee J.; Ahn, Andrew H.; Heckman, C. J.; Fenrich, Keith K.; Fouad, Karim; Bennett, David J.

doi: 10.1152/jn.00805.2018pmid: 30625007

Brain stem-derived serotonin potently inhibits afferent transmission in the monosynaptic stretch reflex. We show that serotonin produces this inhibition exclusively via 5-HT1D receptors, and yet these receptors are paradoxically mostly confined to C-fibers. This suggests that serotonin acts by gating of C-fiber activity, which in turn modulates afferent transmission to motoneurons. We also show that the classic supersensitivity to 5-HT after spinal cord injury results from a loss of SERT, and not 5-HT1D receptor plasticity.

Labruna, Ludovica; Tischler, Claudia; Cazares, Christian; Greenhouse, Ian; Duque, Julie; Lebon, Florent; Ivry, Richard B.

doi: 10.1152/jn.00711.2018pmid: 30785815

Using transcranial magnetic stimulation, we examined changes in corticospinal excitability as people prepared to move. Consistent with previous work, we observed a reduction in excitability during the preparatory period, an effect observed in both task-relevant and task-irrelevant muscles. However, this preparatory inhibition is anatomically constrained, attenuated in muscles belonging to a different body segment than the agonist of the forthcoming movement.

van den Broeke, E. N.; Hartgerink, D. M.; Butler, J.; Lambert, J.; Mouraux, A.

doi: 10.1152/jn.00816.2018pmid: 30785805

We provide the first demonstration in humans that activity-dependent central sensitization increases pinprick-evoked autonomic arousal measured by enhanced pupil dilation response.

Pertermann, Maik; Mückschel, Moritz; Adelhöfer, Nico; Ziemssen, Tjalf; Beste, Christian

doi: 10.1152/jn.00701.2018pmid: 30811254

This is the first study showing that there is a nexus between norepinephrine system activity and the modulation of neural noise or scale-free neural activity during inhibitory control in humans. It does so by integrating pupil diameter data with analysis of EEG neural noise.

Singh, Natasha; Hammam, Elie; Macefield, Vaughan G.

doi: 10.1152/jn.00679.2018pmid: 30811260

Vestibulosympathetic reflexes have been documented in experimental animals and humans. Here we show that sinusoidal galvanic vestibular stimulation, a means of selectively exciting vestibular afferents in humans, induces greater modulation of muscle sympathetic nerve activity when delivered at a very low frequency (0.05 Hz) than at 0.5 or 5.0 Hz.

Petrin, Dylan; Gagolewicz, Peter J.; Mehder, Rasha H.; Bennett, Brian M.; Jin, Albert Y.; Andrew, R. David

doi: 10.1152/jn.00670.2018pmid: 30811255

It is generally accepted that the injured core region of the brain resulting from a focal stroke contains no functioning neurons. Our study shows that some neurons, although surrounded by devastated neighbors, can maintain their structure and electrical activity. This surprising finding raises the possibility of discovering how these neurons are protected to pinpoint new strategies for reducing stroke injury.

McKeown, Daniel J.; Simmonds, Michael J.; Kavanagh, Justin J.

doi: 10.1152/jn.00071.2019pmid: 30864856

The mechanisms of compromised motor control when exposed to hypoxia are largely unknown. The current study examined how severe acute hypoxia affects motor unit firing rate during sustained isometric contractions of the bicep brachii. The response to hypoxia was different across subjects, where motor unit firing rate increased for some individuals and decreased for others. This bidirectional change in firing rate was associated with how fast subjects desaturated during hypoxic exposure.

Milosevic, Matija; Masugi, Yohei; Sasaki, Atsushi; Sayenko, Dimitry G.; Nakazawa, Kimitaka

doi: 10.1152/jn.00802.2018pmid: 30840527

Despite therapeutic effects that have been demonstrated previously using noninvasive cervical spinal stimulation, it has been unclear whether, and to what degree, the stimulation can activate the sensory afferent system. Our study presents evidence that cervical transcutaneous spinal cord stimulation can engage the sensory pathways and transsynaptically converge on motor pools projecting to upper limb muscles, demonstrating the utility and sensitivity of cervical spinal stimulation for electrophysiological assessments and neurorehabilitation.