1
|
Wolpaw JR, Kamesar A. Heksor: The CNS substrate of an adaptive behavior. J Physiol 2022; 600:3423-3452. [PMID: 35771667 PMCID: PMC9545119 DOI: 10.1113/jp283291] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 06/20/2022] [Indexed: 11/16/2022] Open
Abstract
Over the past half‐century, the largely hardwired central nervous system (CNS) of 1970 has become the ubiquitously plastic CNS of today, in which change is the rule not the exception. This transformation complicates a central question in neuroscience: how are adaptive behaviours – behaviours that serve the needs of the individual – acquired and maintained through life? It poses a more basic question: how do many adaptive behaviours share the ubiquitously plastic CNS? This question compels neuroscience to adopt a new paradigm. The core of this paradigm is a CNS entity with unique properties, here given the name heksor from the Greek hexis. A heksor is a distributed network of neurons and synapses that changes itself as needed to maintain the key features of an adaptive behaviour, the features that make the behaviour satisfactory. Through their concurrent changes, the numerous heksors that share the CNS negotiate the properties of the neurons and synapses that they all use. Heksors keep the CNS in a state of negotiated equilibrium that enables each heksor to maintain the key features of its behaviour. The new paradigm based on heksors and the negotiated equilibrium they create is supported by animal and human studies of interactions among new and old adaptive behaviours, explains otherwise inexplicable results, and underlies promising new approaches to restoring behaviours impaired by injury or disease. Furthermore, the paradigm offers new and potentially important answers to extant questions, such as the generation and function of spontaneous neuronal activity, the aetiology of muscle synergies, and the control of homeostatic plasticity.
![]()
Collapse
Affiliation(s)
- Jonathan R Wolpaw
- Director, National Center for Adaptive Neurotechnologies, Professor of Biomedical Sciences, State University of New York at Albany, Albany Stratton VA Medical Center, Albany, NY, 12208
| | - Adam Kamesar
- Professor of Judaeo-Hellenistic Literature, Hebrew Union College, Cincinnati, Ohio, 45220
| |
Collapse
|
2
|
Li SS, Hua XY, Zheng MX, Wu JJ, Ma ZZ, Xing XX, Ma J, Shan CL, Xu JG. Electroacupuncture treatment improves motor function and neurological outcomes after cerebral ischemia/reperfusion injury. Neural Regen Res 2021; 17:1545-1555. [PMID: 34916440 PMCID: PMC8771092 DOI: 10.4103/1673-5374.330617] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Electroacupuncture (EA) has been widely used for functional restoration after stroke. However, its role in post-stroke rehabilitation and the associated regulatory mechanisms remain poorly understood. In this study, we applied EA to the Zusanli (ST36) and Quchi (LI11) acupoints in rats with middle cerebral artery occlusion and reperfusion. We found that EA effectively increased the expression of brain-derived neurotrophic factor and its receptor tyrosine kinase B, synapsin-1, postsynaptic dense protein 95, and microtubule-associated protein 2 in the ischemic penumbra of rats with middle cerebral artery occlusion and reperfusion. Moreover, EA greatly reduced the expression of myelin-related inhibitors Nogo-A and NgR in the ischemic penumbra. Tyrosine kinase B inhibitor ANA-12 weakened the therapeutic effects of EA. These findings suggest that EA can improve neurological function after middle cerebral artery occlusion and reperfusion, possibly through regulating the activity of the brain-derived neurotrophic factor/tyrosine kinase B signal pathway. All procedures and experiments were approved by the Animal Research Committee of Shanghai University of Traditional Chinese Medicine, China (approval No. PZSHUTCM200110002) on January 10, 2020.
Collapse
Affiliation(s)
- Si-Si Li
- School of Rehabilitation Science, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Xu-Yun Hua
- Department of Traumatology and Orthopedics, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Mou-Xiong Zheng
- Department of Traumatology and Orthopedics, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Jia-Jia Wu
- Center of Rehabilitation Medicine, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Zhen-Zhen Ma
- School of Rehabilitation Science, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Xiang-Xin Xing
- School of Rehabilitation Science, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Jie Ma
- School of Rehabilitation Science, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Chun-Lei Shan
- School of Rehabilitation Science; Center of Rehabilitation Medicine, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine; Engineering Research Center of Traditional Chinese Medicine Intelligent Rehabilitation, Ministry of Education, Shanghai, China
| | - Jian-Guang Xu
- School of Rehabilitation Science, Shanghai University of Traditional Chinese Medicine; Engineering Research Center of Traditional Chinese Medicine Intelligent Rehabilitation, Ministry of Education, Shanghai, China
| |
Collapse
|
3
|
Abbasi A, Danielsen NP, Leung J, Muhammad AKMG, Patel S, Gulati T. Epidural cerebellar stimulation drives widespread neural synchrony in the intact and stroke perilesional cortex. J Neuroeng Rehabil 2021; 18:89. [PMID: 34039346 PMCID: PMC8157634 DOI: 10.1186/s12984-021-00881-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 05/19/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Cerebellar electrical stimulation has shown promise in improving motor recovery post-stroke in both rodent and human studies. Past studies have used motor evoked potentials (MEPs) to evaluate how cerebellar stimulation modulates ongoing activity in the cortex, but the underlying mechanisms are incompletely understood. Here we used invasive electrophysiological recordings from the intact and stroke-injured rodent primary motor cortex (M1) to assess how epidural cerebellar stimulation modulates neural dynamics at the level of single neurons as well as at the level of mesoscale dynamics. METHODS We recorded single unit spiking and local field potentials (LFPs) in both the intact and acutely stroke-injured M1 contralateral to the stimulated cerebellum in adult Long-Evans rats under anesthesia. We analyzed changes in the firing rates of single units, the extent of synchronous spiking and power spectral density (PSD) changes in LFPs during and post-stimulation. RESULTS Our results show that post-stimulation, the firing rates of a majority of M1 neurons changed significantly with respect to their baseline rates. These firing rate changes were diverse in character, as the firing rate of some neurons increased while others decreased. Additionally, these changes started to set in during stimulation. Furthermore, cross-correlation analysis showed a significant increase in coincident firing amongst neuronal pairs. Interestingly, this increase in synchrony was unrelated to the direction of firing rate change. We also found that neuronal ensembles derived through principal component analysis were more active post-stimulation. Lastly, these changes occurred without a significant change in the overall spectral power of LFPs post-stimulation. CONCLUSIONS Our results show that cerebellar stimulation caused significant, long-lasting changes in the activity patterns of M1 neurons by altering firing rates, boosting neural synchrony and increasing neuronal assemblies' activation strength. Our study provides evidence that cerebellar stimulation can directly modulate cortical dynamics. Since these results are present in the perilesional cortex, our data might also help explain the facilitatory effects of cerebellar stimulation post-stroke.
Collapse
Affiliation(s)
- Aamir Abbasi
- Center for Neural Science and Medicine, Departments of Biomedical Sciences and Neurology, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Nathan P Danielsen
- Center for Neural Science and Medicine, Departments of Biomedical Sciences and Neurology, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Jennifer Leung
- PhD Program in Biomedical Sciences, Graduate School of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - A K M G Muhammad
- Center for Neural Science and Medicine, Departments of Biomedical Sciences and Neurology, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Saahil Patel
- Center for Neural Science and Medicine, Departments of Biomedical Sciences and Neurology, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Tanuj Gulati
- Center for Neural Science and Medicine, Departments of Biomedical Sciences and Neurology, Cedars-Sinai Medical Center, Los Angeles, CA, USA. .,Department of Medicine, David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, CA, USA. .,Department of Bioengineering, Henri Samueli School of Engineering, University of California-Los Angeles, Los Angeles, CA, USA.
| |
Collapse
|
4
|
Moore B, Khang S, Francis JT. Noise-Correlation Is Modulated by Reward Expectation in the Primary Motor Cortex Bilaterally During Manual and Observational Tasks in Primates. Front Behav Neurosci 2020; 14:541920. [PMID: 33343308 PMCID: PMC7739882 DOI: 10.3389/fnbeh.2020.541920] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 09/30/2020] [Indexed: 11/17/2022] Open
Abstract
Reward modulation is represented in the motor cortex (M1) and could be used to implement more accurate decoding models to improve brain-computer interfaces (BCIs; Zhao et al., 2018). Analyzing trial-to-trial noise-correlations between neural units in the presence of rewarding (R) and non-rewarding (NR) stimuli adds to our understanding of cortical network dynamics. We utilized Pearson's correlation coefficient to measure shared variability between simultaneously recorded units (32-112) and found significantly higher noise-correlation and positive correlation between the populations' signal- and noise-correlation during NR trials as compared to R trials. This pattern is evident in data from two non-human primates (NHPs) during single-target center out reaching tasks, both manual and action observation versions. We conducted a mean matched noise-correlation analysis to decouple known interactions between event-triggered firing rate changes and neural correlations. Isolated reward discriminatory units demonstrated stronger correlational changes than units unresponsive to reward firing rate modulation, however, the qualitative response was similar, indicating correlational changes within the network as a whole can serve as another information channel to be exploited by BCIs that track the underlying cortical state, such as reward expectation, or attentional modulation. Reward expectation and attention in return can be utilized with reinforcement learning (RL) towards autonomous BCI updating.
Collapse
Affiliation(s)
- Brittany Moore
- Department of Biomedical Engineering, Cullen College of Engineering, The University of Houston, Houston, TX, United States
| | - Sheng Khang
- Department of Biomedical Engineering, Cullen College of Engineering, The University of Houston, Houston, TX, United States
| | - Joseph Thachil Francis
- Department of Biomedical Engineering, Cullen College of Engineering, The University of Houston, Houston, TX, United States
- Department of Electrical and Computer Engineering, Cullen College of Engineering, The University of Houston, Houston, TX, United States
| |
Collapse
|
5
|
Arntzen EC, Straume BK, Odeh F, Feys P, Zanaboni P, Normann B. Group-Based Individualized Comprehensive Core Stability Intervention Improves Balance in Persons With Multiple Sclerosis: A Randomized Controlled Trial. Phys Ther 2019; 99:1027-1038. [PMID: 30722036 PMCID: PMC6665948 DOI: 10.1093/ptj/pzz017] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2017] [Accepted: 10/23/2018] [Indexed: 12/13/2022]
Abstract
BACKGROUND Balance and trunk control are often impaired in individuals with multiple sclerosis (MS). Interventions addressing these issues are needed. OBJECTIVE The objective of this study was to compare the immediate and long-term effects of a 6-week individualized, group-based, comprehensive core stability intervention (GroupCoreDIST) with standard care on balance and trunk control in individuals with MS. DESIGN This study was a prospective, assessor-masked, randomized controlled trial. SETTING The GroupCoreDIST intervention was conducted by 6 physical therapists in 6 municipalities in Norway. Standard care included the usual care for individuals with MS in the same municipalities. Assessments at all time points took place at a Norwegian hospital. PARTICIPANTS Eighty people with Expanded Disability Status scores of 1 to 6.5 participated in this trial. INTERVENTION Randomized, concealed allocation was used to assign the participants to the GroupCoreDIST intervention (n = 40) or to standard care (n = 40). The GroupCoreDIST intervention was conducted with groups of 3 participants (1 group had 4 participants), for 60 minutes 3 times per week. MEASUREMENTS Assessments were undertaken at baseline and at weeks 7, 18, and 30. Outcomes were measured with the Trunk Impairment Scale-Norwegian Version, Mini Balance Evaluation Systems Test, and Patient Global Impression of Change-Balance. Repeated-measures mixed models were used for statistical analysis. RESULTS One individual missed all postintervention tests, leaving 79 participants in the intention-to-treat analysis. GroupCoreDIST produced significant between-group effects on the mean difference in the following scores at 7, 18, and 30 weeks: for Trunk Impairment Scale-Norwegian Version, 2.63 points (95% confidence interval [CI] = 1.89-3.38), 1.57 points (95% CI = 0.81-2.33), and 0.95 point (95% CI = 0.19-1.71), respectively; for Mini Balance Evaluation Systems Test, 1.91 points (95% CI = 1.07-2.76), 1.28 points (95% CI = 0.42-2.15), and 0.91 points (95% CI = 0.04-1.77), respectively; and for Patient Global Impression of Change-Balance, 1.21 points (95% CI = 1.66-0.77), 1.02 points (95% CI = 1.48-0.57), and 0.91 points (95% CI = 1.36-0.46), respectively. LIMITATIONS Groups were not matched for volume of physical therapy. CONCLUSIONS Six weeks of GroupCoreDIST improved balance and trunk control in the short and long terms compared with standard care in individuals who were ambulant and had MS. The intervention is an effective contribution to physical therapy for this population.
Collapse
Affiliation(s)
- Ellen Christin Arntzen
- Nordland Hospital Trust, Department of Physical Therapy, 8028 Bodø, Norway,Address all correspondence to Ms Arntzen at:
| | | | - Francis Odeh
- Nordland Hospital Trust, Department of Neurology; and Institute for Clinical Medicine, Faculty of Health Science, UiT The Arctic University of Norway, Tromsø, Norway
| | - Peter Feys
- Department of Biomed-Reva, University of Hasselt, Hasselt, Belgium
| | - Paolo Zanaboni
- National Center for E-Health Research, Future Journal, Tromsø, Norway
| | - Britt Normann
- Department of Health and Care Sciences, UiT The Arctic University of Norway; and Nordland Hospital Trust, Department of Physical Therapy
| |
Collapse
|
6
|
Arntzen EC, Straume B, Odeh F, Feys P, Normann B. Group‐based, individualized, comprehensive core stability and balance intervention provides immediate and long‐term improvements in walking in individuals with multiple sclerosis: A randomized controlled trial. PHYSIOTHERAPY RESEARCH INTERNATIONAL 2019; 25:e1798. [DOI: 10.1002/pri.1798] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 03/12/2019] [Accepted: 05/17/2019] [Indexed: 01/22/2023]
Affiliation(s)
| | - Bjørn Straume
- Department of Community Medicine, Faculty of Health SciencesUiT, The Arctic University of Norway Tromsø Norway
| | - Francis Odeh
- Institute for Clinical Medicine, Faculty of Health ScienceUiT, The Arctic University of Norway Tromsø Norway
- Department of NeurologyNordland Hospital Trust Bodø Norway
| | - Peter Feys
- BIOMED/REVALUniversity of Hasselt Diepenbeek Belgium
| | - Britt Normann
- Department of PhysiotherapyNordland Hospital Trust Bodø Norway
- Department of Health and Care SciencesUiT, The Arctic University of Norway Tromsø Norway
| |
Collapse
|
7
|
Hishinuma AK, Gulati T, Burish MJ, Ganguly K. Large-scale changes in cortical dynamics triggered by repetitive somatosensory electrical stimulation. J Neuroeng Rehabil 2019; 16:59. [PMID: 31126339 PMCID: PMC6534962 DOI: 10.1186/s12984-019-0520-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 03/29/2019] [Indexed: 12/03/2022] Open
Abstract
Background Repetitive somatosensory electrical stimulation (SES) of forelimb peripheral nerves is a promising therapy; studies have shown that SES can improve motor function in stroke subjects with chronic deficits. However, little is known about how SES can directly modulate neural dynamics. Past studies using SES have primarily used noninvasive methods in human subjects. Here we used electrophysiological recordings from the rodent primary motor cortex (M1) to assess how SES affects neural dynamics at the level of single neurons as well as at the level of mesoscale dynamics. Methods We performed acute extracellular recordings in 7 intact adult Long Evans rats under ketamine-xylazine anesthesia while they received transcutaneous SES. We recorded single unit spiking and local field potentials (LFP) in the M1 contralateral to the stimulated arm. We then compared neural firing rate, spike-field coherence (SFC), and power spectral density (PSD) before and after stimulation. Results Following SES, the firing rate of a majority of neurons changed significantly from their respective baseline values. There was, however, a diversity of responses; some neurons increased while others decreased their firing rates. Interestingly, SFC, a measure of how a neuron’s firing is coupled to mesoscale oscillatory dynamics, increased specifically in the δ-band, also known as the low frequency band (0.3- 4 Hz). This increase appeared to be driven by a change in the phase-locking of broad-spiking, putative pyramidal neurons. These changes in the low frequency range occurred without a significant change in the overall PSD. Conclusions Repetitive SES significantly and persistently altered the local cortical dynamics of M1 neurons, changing both firing rates as well as the SFC magnitude in the δ-band. Thus, SES altered the neural firing and coupling to ongoing mesoscale dynamics. Our study provides evidence that SES can directly modulate cortical dynamics.
Collapse
Affiliation(s)
- April K Hishinuma
- Neurology & Rehabilitation Service, San Francisco Veterans Affairs Medical Center, San Francisco, CA, USA.,Department of Neurology, University of California, San Francisco, San Francisco, CA, USA
| | - Tanuj Gulati
- Department of Neurology, University of California, San Francisco, San Francisco, CA, USA.,Department of Biomedical Sciences and Neurology, Cedars-Sinai, Los Angeles, CA, USA
| | - Mark J Burish
- Department of Neurology, University of California, San Francisco, San Francisco, CA, USA.,Department of Neurosurgery, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Karunesh Ganguly
- Neurology & Rehabilitation Service, San Francisco Veterans Affairs Medical Center, San Francisco, CA, USA. .,Department of Neurology, University of California, San Francisco, San Francisco, CA, USA.
| |
Collapse
|
8
|
Wolpaw JR. The negotiated equilibrium model of spinal cord function. J Physiol 2018; 596:3469-3491. [PMID: 29663410 PMCID: PMC6092289 DOI: 10.1113/jp275532] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 04/05/2018] [Indexed: 12/25/2022] Open
Abstract
The belief that the spinal cord is hardwired is no longer tenable. Like the rest of the CNS, the spinal cord changes during growth and ageing, when new motor behaviours are acquired, and in response to trauma and disease. This paper describes a new model of spinal cord function that reconciles its recently appreciated plasticity with its long-recognized reliability as the final common pathway for behaviour. According to this model, the substrate of each motor behaviour comprises brain and spinal plasticity: the plasticity in the brain induces and maintains the plasticity in the spinal cord. Each time a behaviour occurs, the spinal cord provides the brain with performance information that guides changes in the substrate of the behaviour. All the behaviours in the repertoire undergo this process concurrently; each repeatedly induces plasticity to preserve its key features despite the plasticity induced by other behaviours. The aggregate process is a negotiation among the behaviours: they negotiate the properties of the spinal neurons and synapses that they all use. The ongoing negotiation maintains the spinal cord in an equilibrium - a negotiated equilibrium - that serves all the behaviours. This new model of spinal cord function is supported by laboratory and clinical data, makes predictions borne out by experiment, and underlies a new approach to restoring function to people with neuromuscular disorders. Further studies are needed to test its generality, to determine whether it may apply to other CNS areas such as the cerebral cortex, and to develop its therapeutic implications.
Collapse
Affiliation(s)
- Jonathan R. Wolpaw
- National Center for Adaptive Neurotechnologies, Wadsworth CenterNYS Department of HealthAlbanyNYUSA
- Department of NeurologyStratton VA Medical CenterAlbanyNYUSA
- Department of Biomedical SciencesSchool of Public HealthSUNY AlbanyNYUSA
- Department of Neurology, Neurological InstituteColumbia UniversityNew YorkNYUSA
| |
Collapse
|
9
|
Toward an autonomous brain machine interface: integrating sensorimotor reward modulation and reinforcement learning. J Neurosci 2015; 35:7374-87. [PMID: 25972167 DOI: 10.1523/jneurosci.1802-14.2015] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
For decades, neurophysiologists have worked on elucidating the function of the cortical sensorimotor control system from the standpoint of kinematics or dynamics. Recently, computational neuroscientists have developed models that can emulate changes seen in the primary motor cortex during learning. However, these simulations rely on the existence of a reward-like signal in the primary sensorimotor cortex. Reward modulation of the primary sensorimotor cortex has yet to be characterized at the level of neural units. Here we demonstrate that single units/multiunits and local field potentials in the primary motor (M1) cortex of nonhuman primates (Macaca radiata) are modulated by reward expectation during reaching movements and that this modulation is present even while subjects passively view cursor motions that are predictive of either reward or nonreward. After establishing this reward modulation, we set out to determine whether we could correctly classify rewarding versus nonrewarding trials, on a moment-to-moment basis. This reward information could then be used in collaboration with reinforcement learning principles toward an autonomous brain-machine interface. The autonomous brain-machine interface would use M1 for both decoding movement intention and extraction of reward expectation information as evaluative feedback, which would then update the decoding algorithm as necessary. In the work presented here, we show that this, in theory, is possible.
Collapse
|
10
|
Upper limb function is normal in patients with restless legs syndrome (Willis-Ekbom Disease). Clin Neurophysiol 2015; 126:736-42. [DOI: 10.1016/j.clinph.2014.07.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Revised: 06/27/2014] [Accepted: 07/07/2014] [Indexed: 11/21/2022]
|
11
|
Wong CC, Ramanathan DS, Gulati T, Won SJ, Ganguly K. An automated behavioral box to assess forelimb function in rats. J Neurosci Methods 2015; 246:30-7. [PMID: 25769277 DOI: 10.1016/j.jneumeth.2015.03.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Revised: 02/26/2015] [Accepted: 03/03/2015] [Indexed: 12/22/2022]
Abstract
BACKGROUND Rodent forelimb reaching behaviors are commonly assessed using a single-pellet reach-to-grasp task. While the task is widely recognized as a very sensitive measure of distal limb function, it is also known to be very labor-intensive, both for initial training and the daily assessment of function. NEW METHOD Using components developed by open-source electronics platforms, we have designed and tested a low-cost automated behavioral box to measure forelimb function in rats. Our apparatus, made primarily of acrylic, was equipped with multiple sensors to control the duration and difficulty of the task, detect reach outcomes, and dispense pellets. Our control software, developed in MATLAB, was also used to control a camera in order to capture and process video during reaches. Importantly, such processing could monitor task performance in near real-time. RESULTS We further demonstrate that the automated apparatus can be used to expedite skill acquisition, thereby increasing throughput as well as facilitating studies of early versus late motor learning. The setup is also readily compatible with chronic electrophysiological monitoring. COMPARISON WITH EXISTING METHODS Compared to a previous version of this task, our setup provides a more efficient method to train and test rodents for studies of motor learning and recovery of function after stroke. The unbiased delivery of behavioral cues and outcomes also facilitates electrophysiological studies. CONCLUSIONS In summary, our automated behavioral box will allow high-throughput and efficient monitoring of rat forelimb function in both healthy and injured animals.
Collapse
Affiliation(s)
- Chelsea C Wong
- Neurology & Rehabilitation Service, San Francisco VA Medical Center, San Francisco, CA, United States; Department of Neurology, University of California, San Francisco, CA, United States
| | - Dhakshin S Ramanathan
- Neurology & Rehabilitation Service, San Francisco VA Medical Center, San Francisco, CA, United States; Psychiatry Service, San Francisco VA Medical Center, San Francisco, CA, United States; Department of Psychiatry, University of California, San Francisco, CA, United States
| | - Tanuj Gulati
- Neurology & Rehabilitation Service, San Francisco VA Medical Center, San Francisco, CA, United States; Department of Neurology, University of California, San Francisco, CA, United States
| | - Seok Joon Won
- Neurology & Rehabilitation Service, San Francisco VA Medical Center, San Francisco, CA, United States; Department of Neurology, University of California, San Francisco, CA, United States
| | - Karunesh Ganguly
- Neurology & Rehabilitation Service, San Francisco VA Medical Center, San Francisco, CA, United States; Department of Neurology, University of California, San Francisco, CA, United States.
| |
Collapse
|
12
|
Tan AM, Waxman SG. Dendritic spine dysgenesis in neuropathic pain. Neurosci Lett 2014; 601:54-60. [PMID: 25445354 DOI: 10.1016/j.neulet.2014.11.024] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Revised: 11/12/2014] [Accepted: 11/15/2014] [Indexed: 12/20/2022]
Abstract
Neuropathic pain is a significant unmet medical need in patients with variety of injury or disease insults to the nervous system. Neuropathic pain often presents as a painful sensation described as electrical, burning, or tingling. Currently available treatments have limited effectiveness and narrow therapeutic windows for safety. More powerful analgesics, e.g., opioids, carry a high risk for chemical dependence. Thus, a major challenge for pain research is the elucidation of the mechanisms that underlie neuropathic pain and developing targeted strategies to alleviate pathological pain. The mechanistic link between dendritic spine structure and circuit function could explain why neuropathic pain is difficult to treat, since nociceptive processing pathways are adversely "hard-wired" through the reorganization of dendritic spines. Several studies in animal models of neuropathic pain have begun to reveal the functional contribution of dendritic spine dysgenesis in neuropathic pain. Previous reports have demonstrated three primary changes in dendritic spine structure on nociceptive dorsal horn neurons following injury or disease, which accompany chronic intractable pain: (I) increased density of dendritic spines, particularly mature mushroom-spine spines, (II) redistribution of spines toward dendritic branch locations close to the cell body, and (III) enlargement of the spine head diameter, which generally presents as a mushroom-shaped spine. Given the important functional implications of spine distribution, density, and shape for synaptic and neuronal function, the study of dendritic spine abnormality may provide a new perspective for investigating pain, and the identification of specific molecular players that regulate spine morphology may guide the development of more effective and long-lasting therapies.
Collapse
Affiliation(s)
- Andrew M Tan
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, CT 06510, USA; Department of Neurology and Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, CT 06516, USA.
| | - Stephen G Waxman
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, CT 06510, USA; Department of Neurology and Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, CT 06516, USA
| |
Collapse
|
13
|
Kim EY, Kim KW. A theoretical framework for cognitive and non-cognitive interventions for older adults: stimulation versus compensation. Aging Ment Health 2014; 18:304-15. [PMID: 24354740 DOI: 10.1080/13607863.2013.868404] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
BACKGROUND Recently, interest in cognitive training for older adults has grown significantly, reflecting a need for preserving the quality of life into late adulthood. In spite of increasing interest in cognitive rehabilitation, recent meta-analyses have questioned reported training gains and determined that cognitive gain from cognitive training might be no larger than the gain observed from active controls such as unspecific, non-cognitive activities. AIMS This paper presents a theoretical framework for clarifying specificity of cognitive training by exploring mechanisms of current cognitive and non-cognitive interventions for older adults. By differentiating compensatory aspects from the components of specific and non-specific stimulation in current training, two related strategies of interventions for age-related cognitive decline, i.e., stimulation versus compensation, are proposed. OVERVIEW Current interventions for age-related cognitive decline are reviewed in terms of stimulation- and compensation-focused interventions. Stimulation-focused, cognitive and non-cognitive training, with or without specific targets, tend to result in general improvement in attention and sensory or other cognitive functions. Meanwhile, compensation-focused training is likely to be the most effective when the intervention specifically supports the frontally mediating activity in accordance with the direction of indigenous adjustments in the aging brain. CONCLUSIONS It can be inferred that stimulation-focused training is to ameliorate the adverse effects of neurological aging, whereas compensation-focused cognitive training is primarily to facilitate compensatory adaptation in the brain.
Collapse
Affiliation(s)
- Eun Young Kim
- a Department of Counseling Psychology , Hanyang Cyber University , Seoul , Republic of Korea
| | | |
Collapse
|
14
|
Mahmoudi B, Pohlmeyer EA, Prins NW, Geng S, Sanchez JC. Towards autonomous neuroprosthetic control using Hebbian reinforcement learning. J Neural Eng 2013; 10:066005. [PMID: 24100047 DOI: 10.1088/1741-2560/10/6/066005] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE Our goal was to design an adaptive neuroprosthetic controller that could learn the mapping from neural states to prosthetic actions and automatically adjust adaptation using only a binary evaluative feedback as a measure of desirability/undesirability of performance. APPROACH Hebbian reinforcement learning (HRL) in a connectionist network was used for the design of the adaptive controller. The method combines the efficiency of supervised learning with the generality of reinforcement learning. The convergence properties of this approach were studied using both closed-loop control simulations and open-loop simulations that used primate neural data from robot-assisted reaching tasks. MAIN RESULTS The HRL controller was able to perform classification and regression tasks using its episodic and sequential learning modes, respectively. In our experiments, the HRL controller quickly achieved convergence to an effective control policy, followed by robust performance. The controller also automatically stopped adapting the parameters after converging to a satisfactory control policy. Additionally, when the input neural vector was reorganized, the controller resumed adaptation to maintain performance. SIGNIFICANCE By estimating an evaluative feedback directly from the user, the HRL control algorithm may provide an efficient method for autonomous adaptation of neuroprosthetic systems. This method may enable the user to teach the controller the desired behavior using only a simple feedback signal.
Collapse
Affiliation(s)
- Babak Mahmoudi
- Department of Neurosurgery, Emory University, Atlanta, GA, USA
| | | | | | | | | |
Collapse
|
15
|
Duncan AF, Caprihan A, Montague EQ, Lowe J, Schrader R, Phillips JP. Regional cerebral blood flow in children from 3 to 5 months of age. AJNR Am J Neuroradiol 2013; 35:593-8. [PMID: 24091444 DOI: 10.3174/ajnr.a3728] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
BACKGROUND AND PURPOSE Understanding the relationship between brain and behavior in early childhood requires a probe of functional brain development. We report the first large study of regional CBF by use of arterial spin-labeling in young children. MATERIALS AND METHODS Cerebral blood flow by use of arterial spin-labeling was measured in 61 healthy children between the ages of 3 and 5 months. Blood flow maps were parcellated into 8 broadly defined anatomic regions of each cerebral hemisphere. RESULTS There was no sex effect; however, group analysis demonstrated significantly greater CBF in the sensorimotor and occipital regions compared with dorsolateral prefrontal, subgenual, and orbitofrontal areas (P < .0001). A significant age effect was also identified, with the largest increase in blood flow between 3 and 5 months occurring in the following regions: orbitofrontal (P < .009), subgenual (P < .002), and inferior occipital lobe (P = .001). CONCLUSIONS These results are consistent with prior histologic studies demonstrating regional variation in brain maturation and suggest that arterial spin-labeling is sensitive to regional as well as age-related differences in CBF in young children.
Collapse
Affiliation(s)
- A F Duncan
- From the Department of Pediatrics, Division of Neonatology (A.F.D., J.L.)
| | | | | | | | | | | |
Collapse
|