scholarly journals Function of the nucleus accumbens in motor control during recovery after spinal cord injury

Science ◽  
2015 ◽  
Vol 350 (6256) ◽  
pp. 98-101 ◽  
Author(s):  
Masahiro Sawada ◽  
Kenji Kato ◽  
Takeharu Kunieda ◽  
Nobuhiro Mikuni ◽  
Susumu Miyamoto ◽  
...  

Motivation facilitates recovery after neuronal damage, but its mechanism is elusive. It is generally thought that the nucleus accumbens (NAc) regulates motivation-driven effort but is not involved in the direct control of movement. Using causality analysis, we identified the flow of activity from the NAc to the sensorimotor cortex (SMC) during the recovery of dexterous finger movements after spinal cord injury at the cervical level in macaque monkeys. Furthermore, reversible pharmacological inactivation of the NAc during the early recovery period diminished high-frequency oscillatory activity in the SMC, which was accompanied by a transient deficit of amelioration in finger dexterity obtained by rehabilitation. These results demonstrate that during recovery after spinal damage, the NAc up-regulates the high-frequency activity of the SMC and is directly involved in the control of finger movements.

2019 ◽  
Vol 30 (5) ◽  
pp. 3259-3270 ◽  
Author(s):  
Michiaki Suzuki ◽  
Kayo Onoe ◽  
Masahiro Sawada ◽  
Nobuaki Takahashi ◽  
Noriyuki Higo ◽  
...  

Abstract In a recent study, we demonstrated that the ventral striatum (VSt) controls finger movements directly during the early recovery stage after spinal cord injury (SCI), implying that the VSt may be a part of neural substrates responsible for the recovery of dexterous finger movements. The VSt is accepted widely as a key node for motivation, but is not thought to be involved in the direct control of limb movements. Therefore, whether a causal relationship exists between the VSt and motor recovery after SCI is unknown, and the role of the VSt in the recovery of dexterous finger movements orfinger movements in general after SCI remains unclear. In the present study, functional brain imaging in a macaque model of SCI revealed a strengthened functional connectivity between motor-related areas and the VSt during the recovery process for precision grip, but not whole finger grip after SCI. Furthermore, permanent lesion of the VSt impeded the recoveryof precision grip, but not coarse grip. Thus, the VSt was needed specifically for functional recovery of dexterous finger movements. These results suggest that the VSt is the key node of the cortical reorganization required for functional recovery of finger dexterity.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Chiaki Yamada ◽  
Aiko Maeda ◽  
Katsuyuki Matsushita ◽  
Shoko Nakayama ◽  
Kazuhiro Shirozu ◽  
...  

Abstract Background Patients with spinal cord injury (SCI) frequently complain of intractable pain that is resistant to conservative treatments. Here, we report the successful application of 1-kHz high-frequency spinal cord stimulation (SCS) in a patient with refractory neuropathic pain secondary to SCI. Case presentation A 69-year-old male diagnosed with SCI (C4 American Spinal Injury Association Impairment Scale A) presented with severe at-level bilateral upper extremity neuropathic pain. Temporary improvement in his symptoms with a nerve block implied peripheral component involvement. The patient received SCS, and though the tip of the leads could not reach the cervical vertebrae, a 1-kHz frequency stimulus relieved the intractable pain. Conclusions SCI-related symptoms may include peripheral components; SCS may have a considerable effect on intractable pain. Even when the SCS electrode lead cannot be positioned in the target area, 1-kHz high-frequency SCS may still produce positive effects.


2020 ◽  
Vol 1 ◽  
Author(s):  
Youngmok Yun ◽  
Youngjin Na ◽  
Paria Esmatloo ◽  
Sarah Dancausse ◽  
Alfredo Serrato ◽  
...  

Abstract We have developed a one-of-a-kind hand exoskeleton, called Maestro, which can power finger movements of those surviving severe disabilities to complete daily tasks using compliant joints. In this paper, we present results from an electromyography (EMG) control strategy conducted with spinal cord injury (SCI) patients (C5, C6, and C7) in which the subjects completed daily tasks controlling Maestro with EMG signals from their forearm muscles. With its compliant actuation and its degrees of freedom that match the natural finger movements, Maestro is capable of helping the subjects grasp and manipulate a variety of daily objects (more than 15 from a standardized set). To generate control commands for Maestro, an artificial neural network algorithm was implemented along with a probabilistic control approach to classify and deliver four hand poses robustly with three EMG signals measured from the forearm and palm. Increase in the scores of a standardized test, called the Sollerman hand function test, and enhancement in different aspects of grasping such as strength shows feasibility that Maestro can be capable of improving the hand function of SCI subjects.


2017 ◽  
Vol 118 (4) ◽  
pp. 2344-2357 ◽  
Author(s):  
Elisa J. Gonzalez-Rothi ◽  
Kristi A. Streeter ◽  
Marie H. Hanna ◽  
Anna C. Stamas ◽  
Paul J. Reier ◽  
...  

C2 spinal hemilesion (C2Hx) paralyzes the ipsilateral diaphragm, but recovery is possible through activation of “crossed spinal” synaptic inputs to ipsilateral phrenic motoneurons. We tested the hypothesis that high-frequency epidural stimulation (HF-ES) would potentiate ipsilateral phrenic output after subacute and chronic C2Hx. HF-ES (300 Hz) was applied to the ventrolateral C4 or T2 spinal cord ipsilateral to C2Hx in anesthetized and mechanically ventilated adult rats. Stimulus duration was 60 s, and currents ranged from 100 to 1,000 µA. Bilateral phrenic nerve activity and ipsilateral hypoglossal (XII) nerve activity were recorded before and after HF-ES. Higher T2 stimulus currents potentiated ipsilateral phasic inspiratory activity at both 2 and 12 wk post-C2Hx, whereas higher stimulus currents delivered at C4 potentiated ipsilateral phasic phrenic activity only at 12 wk ( P = 0.028). Meanwhile, tonic output in the ipsilateral phrenic nerve reached 500% of baseline values at the high currents with no difference between 2 and 12 wk. HF-ES did not trigger inspiratory burst-frequency changes. Similar responses occurred following T2 HF-ES. Increases in contralateral phrenic and XII nerve output were induced by C4 and T2 HF-ES at higher currents, but the relative magnitude of these changes was small compared with the ipsilateral phrenic response. We conclude that following incomplete cervical spinal cord injury, HF-ES of the ventrolateral midcervical or thoracic spinal cord can potentiate efferent phrenic motor output with little impact on inspiratory burst frequency. However, the substantial increases in tonic output indicate that the uninterrupted 60-s stimulation paradigm used is unlikely to be useful for respiratory muscle activation after spinal injury. NEW & NOTEWORTHY Previous studies reported that high-frequency epidural stimulation (HF-ES) activates the diaphragm following acute spinal transection. This study examined HF-ES and phrenic motor output following subacute and chronic incomplete cervical spinal cord injury. Short-term potentiation of phrenic bursting following HF-ES illustrates the potential for spinal stimulation to induce respiratory neuroplasticity. Increased tonic phrenic output indicates that alternatives to the continuous stimulation paradigm used in this study will be required for respiratory muscle activation after spinal cord injury.


2017 ◽  
Vol 117 (6) ◽  
pp. 2282-2291 ◽  
Author(s):  
Wei Zhou ◽  
Tongzhou Yuan ◽  
Youshui Gao ◽  
Peipei Yin ◽  
Wei Liu ◽  
...  

Excessive inflammation including IL-1β-initiated signaling is among the earlies reactions that can cause neuronal damage following spinal cord injury (SCI). It has been suggested that microRNAs may participate in stem cell repair to facilitate functional recovery following SCI. In this study we have shown that in cultured human neural stem cells (hNSC), IL-1β reduced the expression of both KIF3B (kinesin family member 3B) and NOSIP (nitric oxide synthase-interacting protein), two key modulators for restricting inflammation and promoting neuronal regeneration. The induction of microRNA-372 (miR-372) by IL-1β is specifically responsible for the inhibition of KIF3B and NOSIP. The 3′-untranslated regions (UTRs) of both KIF3B and NOSIP contain targeting sequences to miR-372 that directly inhibit their expression. Moreover, we found that the expression of miR-372 was stimulated in hNSC by IL-1β through an NF-κB binding site at its promoter region. Finally, stable overexpression of miR-372 inhibitor in hNSC rescued the IL-1β-induced impairment as shown by significant improvements in tissue water content, myeloperoxidase activity, and behavioral assessments in SCI rats. These findings suggest a critical role of miR-372 in inflammatory signaling and pinpoint a novel target for the treatment of acute SCI. NEW & NOTEWORTHY Our data demonstrate that IL-1β can impair the functional recovery of neural stem cell transplant therapy for spinal cord injury (SCI) treatment in rats. This effect is dependent on microRNA-372 (miR-372)-dependent gene repression of KIF3B and NOSIP. Therefore, specific knockdown of miR-372 may provide benefits for SCI treatments.


Brain ◽  
2020 ◽  
Author(s):  
Tobias Zrzavy ◽  
Carmen Schwaiger ◽  
Isabella Wimmer ◽  
Thomas Berger ◽  
Jan Bauer ◽  
...  

Abstract Traumatic spinal cord injury is a devastating insult followed by progressive cord atrophy and neurodegeneration. Dysregulated or non-resolving inflammatory processes can disturb neuronal homeostasis and drive neurodegeneration. Here, we provide an in-depth characterization of innate and adaptive inflammatory responses as well as oxidative tissue injury in human traumatic spinal cord injury lesions compared to non-traumatic control cords. In the lesion core, microglia were rapidly lost while intermediate (co-expressing pro- as well as anti-inflammatory molecules) blood-borne macrophages dominated. In contrast, in the surrounding rim, TMEM119+ microglia numbers were maintained through local proliferation and demonstrated a predominantly pro-inflammatory phenotype. Lymphocyte numbers were low and mainly consisted of CD8+ T cells. Only in a subpopulation of patients, CD138+/IgG+ plasma cells were detected, which could serve as candidate cellular sources for a developing humoral immunity. Oxidative neuronal cell body and axonal injury was visualized by intracellular accumulation of amyloid precursor protein (APP) and oxidized phospholipids (e06) and occurred early within the lesion core and declined over time. In contrast, within the surrounding rim, pronounced APP+/e06+ axon-dendritic injury of neurons was detected, which remained significantly elevated up to months/years, thus providing mechanistic evidence for ongoing neuronal damage long after initial trauma. Dynamic and sustained neurotoxicity after human spinal cord injury might be a substantial contributor to (i) an impaired response to rehabilitation; (ii) overall failure of recovery; or (iii) late loss of recovered function (neuro-worsening/degeneration).


RSC Advances ◽  
2017 ◽  
Vol 7 (5) ◽  
pp. 2979-2991 ◽  
Author(s):  
Yichao Jin ◽  
Shaofeng Yang ◽  
Xiaohua Zhang

Interaction between autophagy and apoptosis participates in the neuroprotective effect of methylprednisolone on spinal cord injury.


Sign in / Sign up

Export Citation Format

Share Document