keyword
MENU ▼
Read by QxMD icon Read
search

reticulospinal

keyword
https://www.readbyqxmd.com/read/29138697/following-spinal-cord-injury-transected-reticulospinal-tract-axons-develop-new-collateral-inputs-to-spinal-interneurons-in-parallel-with-locomotor-recovery
#1
Zacnicte May, Keith K Fenrich, Julia Dahlby, Nicholas J Batty, Abel Torres-Espín, Karim Fouad
The reticulospinal tract (RtST) descends from the reticular formation and terminates in the spinal cord. The RtST drives the initiation of locomotion and postural control. RtST axons form new contacts with propriospinal interneurons (PrINs) after incomplete spinal cord injury (SCI); however, it is unclear if injured or uninjured axons make these connections. We completely transected all traced RtST axons in rats using a staggered model, where a hemisection SCI at vertebra T10 is followed by a contralateral hemisection at vertebra T7...
2017: Neural Plasticity
https://www.readbyqxmd.com/read/29097251/fear-conditioned-alterations-of-motor-cortex-excitability-the-role-of-amygdala
#2
Selim Gökdemir, Ayşegül Gündüz, Çiğdem Özkara, Meral E Kızıltan
BACKGROUND AND OBJECTIVE: We hypothesized that fear-conditioning may increase motor cortical excitability in preparation for response to fear. We tested our hypothesis in healthy subjects and in the second step, to determine the role of amygdala in alterations of motor cortex excitability, we included a group of patients who previously underwent unilateral amygdalo-hippocampectomy for temporal lobe epilepsy. PATIENTS AND METHODS: In the first step, we included 16 healthy volunteers...
October 31, 2017: Neuroscience Letters
https://www.readbyqxmd.com/read/28924005/nigral-glutamatergic-neurons-control-the-speed-of-locomotion
#3
Dimitri Ryczko, Swantje Grätsch, Laura Schläger, Avo Keuyalian, Zakaria Boukhatem, Claudia Garcia, François Auclair, Ansgar Büschges, Réjean Dubuc
The mesencephalic locomotor region (MLR) plays a crucial role in locomotor control. In vertebrates, stimulation of the MLR at increasing intensities elicits locomotion of growing speed. This effect has been presumed to result from higher brain inputs activating the MLR like a dimmer switch. Here, we show in lampreys (Petromyzon marinus) of either sex that incremental stimulation of a region homologous to the mammalian substantia nigra pars compacta (SNc) evokes increasing activation of MLR cells with a graded increase in the frequency of locomotor movements...
October 4, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28912689/monoamine-release-in-the-cat-lumbar-spinal-cord-during-fictive-locomotion-evoked-by-the-mesencephalic-locomotor-region
#4
Brian R Noga, Riza P Turkson, Songtao Xie, Annette Taberner, Alberto Pinzon, Ian D Hentall
Spinal cord neurons active during locomotion are innervated by descending axons that release the monoamines serotonin (5-HT) and norepinephrine (NE) and these neurons express monoaminergic receptor subtypes implicated in the control of locomotion. The timing, level and spinal locations of release of these two substances during centrally-generated locomotor activity should therefore be critical to this control. These variables were measured in real time by fast-cyclic voltammetry in the decerebrate cat's lumbar spinal cord during fictive locomotion, which was evoked by electrical stimulation of the mesencephalic locomotor region (MLR) and registered as integrated activity in bilateral peripheral nerves to hindlimb muscles...
2017: Frontiers in Neural Circuits
https://www.readbyqxmd.com/read/28889979/visual-threat-assessment-and-reticulospinal-encoding-of-calibrated-responses-in-larval-zebrafish
#5
Kiran Bhattacharyya, David L McLean, Malcolm A MacIver
All visual animals must decide whether approaching objects are a threat. Our current understanding of this process has identified a proximity-based mechanism where an evasive maneuver is triggered when a looming stimulus passes a subtended visual angle threshold. However, some escape strategies are more costly than others, and so it would be beneficial to additionally encode the level of threat conveyed by the predator's approach rate to select the most appropriate response. Here, using naturalistic rates of looming visual stimuli while simultaneously monitoring escape behavior and the recruitment of multiple reticulospinal neurons, we find that larval zebrafish do indeed perform a calibrated assessment of threat...
September 25, 2017: Current Biology: CB
https://www.readbyqxmd.com/read/28871033/reticulospinal-contributions-to-gross-hand-function-after-human-spinal-cord-injury
#6
Stuart N Baker, Monica A Perez
Multiple descending motor pathways likely contribute to the recovery of hand motor function following spinal cord injury (SCI). Reticulospinal neurons project to spinal motor neurons controlling hand muscles and extensively sprout into gray matter structures after SCI; therefore, it has been proposed that the reticulospinal tract is one of the descending motor pathways involved in recovery of hand function after injury. To test this hypothesis, we examined the StartReact response, an involuntary release of a planned movement via a startling stimulus that engages the reticulospinal tract, by measuring reaction times from electromyographic activity in an intrinsic finger muscle during three motor tasks requiring different degrees of hand dexterity: index finger abduction, a precision grip, and a power grip...
October 4, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28813815/how-do-strength-and-coordination-recovery-interact-after-stroke-a-computational-model-for-informing-robotic-training
#7
Sumner L Norman, Joan Lobo-Prat, David J Reinkensmeyer
Robotic devices can train strength, coordination, or a combination of both. If a robotic device focuses on coordination, what happens to strength recovery, and vice versa? Understanding this interaction could help optimize robotic training. We developed a computational neurorehabilitation model to gain insight into the interaction between strength and coordination recovery after stroke. In the model, the motor system recovers by optimizing the activity of residual corticospinal cells (focally connected, excitatory and inhibitory) and reticulospinal cells (diffusely connected and excitatory) to achieve a motor task...
July 2017: IEEE ... International Conference on Rehabilitation Robotics: [proceedings]
https://www.readbyqxmd.com/read/28659855/upper-extremity-motor-impairments-and-microstructural-changes-in-bulbospinal-pathways-in-chronic-hemiparetic-stroke
#8
Meriel Owen, Carson Ingo, Julius P A Dewald
Following hemiparetic stroke, precise, individuated control of single joints is often replaced by highly stereotyped patterns of multi-joint movement, or abnormal limb synergies, which can negatively impact functional use of the paretic arm. One hypothesis for the expression of these synergies is an increased dependence on bulbospinal pathways such as the rubrospinal (RubST) tract and especially the reticulospinal (RetST) tracts, which co-activate multiple muscles of the shoulder, elbow, wrist, and fingers...
2017: Frontiers in Neurology
https://www.readbyqxmd.com/read/28603482/dopamine-and-the-brainstem-locomotor-networks-from-lamprey-to-human
#9
REVIEW
Dimitri Ryczko, Réjean Dubuc
In vertebrates, dopamine neurons are classically known to modulate locomotion via their ascending projections to the basal ganglia that project to brainstem locomotor networks. An increased dopaminergic tone is associated with increase in locomotor activity. In pathological conditions where dopamine cells are lost, such as in Parkinson's disease, locomotor deficits are traditionally associated with the reduced ascending dopaminergic input to the basal ganglia. However, a descending dopaminergic pathway originating from the substantia nigra pars compacta was recently discovered...
2017: Frontiers in Neuroscience
https://www.readbyqxmd.com/read/28562670/increased-threshold-of-short-latency-motor-evoked-potentials-in-transgenic-mice-expressing-channelrhodopsin-2
#10
Wei Wu, Wenhui Xiong, Ping Zhang, Lifang Chen, Jianqiao Fang, Christopher Shields, Xiao-Ming Xu, Xiaoming Jin
Transgenic mice that express channelrhodopsin-2 or its variants provide a powerful tool for optogenetic study of the nervous system. Previous studies have established that introducing such exogenous genes usually does not alter anatomical, electrophysiological, and behavioral properties of neurons in these mice. However, in a line of Thy1-ChR2-YFP transgenic mice (line 9, Jackson lab), we found that short-latency motor evoked potentials (MEPs) induced by transcranial magnetic stimulation had a longer latency and much lower amplitude than that of wild type mice...
2017: PloS One
https://www.readbyqxmd.com/read/28553321/rhoa-as-a-target-to-promote-neuronal-survival-and-axon-regeneration
#11
REVIEW
Jianli Hu, Michael E Selzer
Paralysis following spinal cord injury (SCI) is due to failure of axonal regeneration. It is believed that the capacities of neurons to regrow their axons are due partly to their intrinsic characteristics, which in turn are greatly influenced by several types of inhibitory molecules that are present, or even increased in the extracellular environment of the injured spinal cord. Many of these inhibitory molecules have been studied extensively in recent years. It has been suggested that the small GTPase RhoA is an intracellular convergence point for signaling by these extracellular inhibitory molecules, but due to the complexity of the central nervous system (CNS) in mammals, and the limitation of pharmacological tools, the specific roles of RhoA are unclear...
April 2017: Neural Regeneration Research
https://www.readbyqxmd.com/read/28549933/orexin-exerts-excitatory-effects-on-reticulospinal-neurons-in-the-rat-gigantocellular-reticular-nucleus-through-the-activation-of-postsynaptic-orexin-1-and-orexin-2-receptors
#12
Nian Yang, Guan-Zhong Wang, Si-Yi Wen, Qi-Cheng Qiao, Yu-Hui Liu, Jun Zhang
Previous studies have revealed that orexin may actively participate in central motor control. The gigantocellular reticular nucleus (Gi) is a key element of the brainstem motor inhibitory system. The descending orexinergic projections also reach Gi region, and microinjection of orexin into Gi causes robust muscle tone inhibition. However, the modulation effects of orexin on Gi neurons remain unclear. In the present study, using whole-cell patch-clamp recordings, we initially observed that orexin elicited an inward current in Gi neurons at a holding potential of -70mV in a concentration-dependent manner...
July 13, 2017: Neuroscience Letters
https://www.readbyqxmd.com/read/28489821/whole-brain-serial-section-electron-microscopy-in-larval-zebrafish
#13
David Grant Colburn Hildebrand, Marcelo Cicconet, Russel Miguel Torres, Woohyuk Choi, Tran Minh Quan, Jungmin Moon, Arthur Willis Wetzel, Andrew Scott Champion, Brett Jesse Graham, Owen Randlett, George Scott Plummer, Ruben Portugues, Isaac Henry Bianco, Stephan Saalfeld, Alexander David Baden, Kunal Lillaney, Randal Burns, Joshua Tzvi Vogelstein, Alexander Franz Schier, Wei-Chung Allen Lee, Won-Ki Jeong, Jeff William Lichtman, Florian Engert
High-resolution serial-section electron microscopy (ssEM) makes it possible to investigate the dense meshwork of axons, dendrites, and synapses that form neuronal circuits. However, the imaging scale required to comprehensively reconstruct these structures is more than ten orders of magnitude smaller than the spatial extents occupied by networks of interconnected neurons, some of which span nearly the entire brain. Difficulties in generating and handling data for large volumes at nanoscale resolution have thus restricted vertebrate studies to fragments of circuits...
May 18, 2017: Nature
https://www.readbyqxmd.com/read/28470551/nuclear-derivatives-and-axonal-projections-originating-from-rhombomere-4-in-the-mouse-hindbrain
#14
Maria Di Bonito, Michèle Studer, Luis Puelles
The r4-derived territory is located in the pontine region of the brainstem, forming a wedge-shaped slice that broadens from the choroidal roof to the ventral midline. R4-derived neuronal populations migrate radially inside and tangentially outside this rhombomere, forming nuclei of the sensorimotor auditory, vestibular, trigeminal and reticular systems. R4-derived fibre tracts contribute to the lateral lemniscus, the trigeminothalamic tracts, the medial tegmental tract and the medial forebrain bundle, which variously project to the midbrain, thalamus, hypothalamus and telencephalon...
May 3, 2017: Brain Structure & Function
https://www.readbyqxmd.com/read/28469003/regulation-of-axonal-regeneration-following-spinal-cord-injury-in-the-lamprey
#15
Jessica A Benes, Kylie N House, Frank N Burks, Kris P Conaway, Donald P Julien, Jeffrey P Donley, Michael A Iyamu, Andrew D McClellan
Following rostral spinal cord injury (SCI) in larval lampreys, injured descending brain neurons, particularly reticulospinal (RS) neurons, regenerate their axons, and locomotor behavior recovers in a few weeks. However, axonal regeneration of descending brain neurons is mostly limited to relatively short distances, but the mechanisms for incomplete axonal regeneration are unclear. First, lampreys with rostral SCI exhibited greater axonal regeneration of descending brain neurons, including RS neurons, as well as more rapid recovery of locomotor muscle activity right below the lesion site, compared with animals with caudal SCI...
September 1, 2017: Journal of Neurophysiology
https://www.readbyqxmd.com/read/28455739/postural-responses-in-the-upper-limbs-evoked-by-axial-impulses-a-role-for-reticulospinal-projections
#16
Baozhing Teng, Sendhil Govender, James G Colebatch
We studied the short-latency (SL) postural effects of axial impulses in 11 subjects (22 ± 2 years old). Recordings were made bilaterally from soleus and tibialis anterior (TA) muscles. We confirmed that with leaning anteriorly and posteriorly, reflex EMG increases occurred in both muscle groups at short latency following brief perturbations applied over C7 or the sternum (soleus mean latencies 57.5 and 66.4 ms; TA mean 51.7 and 55.4 ms, respectively). While the size of the SL reflexes was affected by the direction of lean when standing we found that light touch did not affect the amplitudes or latencies significantly...
July 2017: Experimental Brain Research. Experimentelle Hirnforschung. Expérimentation Cérébrale
https://www.readbyqxmd.com/read/28421032/spasticity-motor-recovery-and-neural-plasticity-after-stroke
#17
REVIEW
Sheng Li
Spasticity and weakness (spastic paresis) are the primary motor impairments after stroke and impose significant challenges for treatment and patient care. Spasticity emerges and disappears in the course of complete motor recovery. Spasticity and motor recovery are both related to neural plasticity after stroke. However, the relation between the two remains poorly understood among clinicians and researchers. Recovery of strength and motor function is mainly attributed to cortical plastic reorganization in the early recovery phase, while reticulospinal (RS) hyperexcitability as a result of maladaptive plasticity, is the most plausible mechanism for poststroke spasticity...
2017: Frontiers in Neurology
https://www.readbyqxmd.com/read/28396651/descending-influences-on-vestibulospinal-and-vestibulosympathetic-reflexes
#18
REVIEW
Andrew A McCall, Derek M Miller, Bill J Yates
This review considers the integration of vestibular and other signals by the central nervous system pathways that participate in balance control and blood pressure regulation, with an emphasis on how this integration may modify posture-related responses in accordance with behavioral context. Two pathways convey vestibular signals to limb motoneurons: the lateral vestibulospinal tract and reticulospinal projections. Both pathways receive direct inputs from the cerebral cortex and cerebellum, and also integrate vestibular, spinal, and other inputs...
2017: Frontiers in Neurology
https://www.readbyqxmd.com/read/28394483/corticobulbar-projections-from-distinct-motor-cortical-areas-to-the-reticular-formation-in-macaque-monkeys
#19
Michela Fregosi, Alessandro Contestabile, Adjia Hamadjida, Eric M Rouiller
Corticospinal and corticobulbar descending pathways act in parallel with brainstem systems, such as the reticulospinal tract, to ensure the control of voluntary movements via direct or indirect influences onto spinal motoneurons. The aim of this study was to investigate the corticobulbar projections from distinct motor cortical areas onto different nuclei of the reticular formation. Seven adult macaque monkeys were analysed for the location of corticobulbar axonal boutons, and one monkey for reticulospinal neurons' location...
April 10, 2017: European Journal of Neuroscience
https://www.readbyqxmd.com/read/28304238/remote-motor-system-metabolic-profile-and-surgery-outcome-in-cervical-spondylotic-myelopathy
#20
Sorin C Craciunas, Mircea R Gorgan, Bogdan Ianosi, Phil Lee, Joseph Burris, Carmen M Cirstea
OBJECTIVE In patients with cervical spondylotic myelopathy (CSM), the motor system may undergo progressive functional/structural changes rostral to the lesion, and these changes may be associated with clinical disability. The extent to which these changes have a prognostic value in the clinical recovery after surgical treatment is not yet known. In this study, magnetic resonance spectroscopy (MRS) was used to test 2 primary hypotheses. 1) Based on evidence of corticospinal and spinocerebellar, rubro-, or reticulospinal tract degeneration/dysfunction during chronic spinal cord compression, the authors hypothesized that the metabolic profile of the primary motor cortices (M1s) and cerebellum, respectively, would be altered in patients with CSM, and these alterations would be associated with the extent of the neurological disabilities...
June 2017: Journal of Neurosurgery. Spine
keyword
keyword
102658
1
2
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"