scholarly journals GABA relates to functional connectivity changes and retention in visuomotor adaptation

2020 ◽  
Author(s):  
Caroline Nettekoven ◽  
Sinead Brady ◽  
William T Clarke ◽  
Uzay Emir ◽  
Jacob Levenstein ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Primary Motor Cortex ◽  
Motor Adaptation ◽  
Visuomotor Adaptation ◽  
Therapeutic Interventions ◽  
Motor Sequence ◽  
Motor Abilities ◽  
Important Challenge ◽  
Behavioural Specificity

SummaryInteracting with our ever-changing physical environment requires continual recalibration of the motor system. One mechanism by which this occurs is motor adaptation. Understanding how motor adaptation is implemented by the human brain, how different regions work in concert to retain adaptive movement accuracy, and how this function is linked to metabolic use of neurochemicals poses an important challenge in neuroscience. In humans, motor sequence learning is related to concentration of γ-aminobutyric acid (GABA) in the primary motor cortex (M1). However, the role of M1 GABA in adaptation – where behaviour is acquired outside M1 but retained within M1 – is unclear. Here, we used an ultra-high field MR multimodal acquisition to address the hypothesis that M1 GABA and M1-Cerebellar functional connectivity would relate to retention of adaptation, but not acquisition of adaptation. As such, we demonstrate higher baseline M1 [GABA] relates to greater retention but does not relate to adaptation-acquisition. This relationship is mediated by change in M1-Cerebellar functional connectivity: higher M1 [GABA] relates to a decreased M1-Cerebellar connectivity, resulting in greater retention. These findings showed anatomical, neurochemical and behavioural specificity: As expected, no relationship was found between retention and a control metabolite, M1 [Glutamate], as well as retention and connectivity change between control regions and no relationship was found between M1 [GABA] and behaviour in a control condition. The implication of a mechanistic link from neurochemistry to retention significantly advances our understanding of population variability in retention behaviour and provides a crucial step towards developing therapeutic interventions to restore motor abilities.

scholarly journals Motor Sequences - Separating The Sequence From The Motor. A longitudinal rsfMRI Study

2021 ◽  
Author(s):  
ATP Jäger ◽  
JM Huntenburg ◽  
SA Tremblay ◽  
U Schneider ◽  
S Grahl ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Motor Learning ◽  
Resting State ◽  
Primary Motor Cortex ◽  
Control Group ◽  
Motor Execution ◽  
Motor Sequence ◽  
Resting State Functional Connectivity ◽  
Fast Learning ◽  
Slow Learning

AbstractIn motor learning, sequence-specificity, i.e. the learning of specific sequential associations, has predominantly been studied using task-based fMRI paradigms. However, offline changes in resting state functional connectivity after sequence-specific motor learning are less well understood. Previous research has established that plastic changes following motor learning can be divided into stages including fast learning, slow learning and retention. A description of how resting state functional connectivity after sequence-specific motor sequence learning (MSL) develops across these stages is missing. This study aimed to identify plastic alterations in whole-brain functional connectivity after learning a complex motor sequence by contrasting an active group who learned a complex sequence with a control group who performed a control task matched for motor execution. Resting state fMRI and behavioural performance were collected in both groups over the course of 5 consecutive training days and at follow-up after 12 days to encompass fast learning, slow learning, overall learning and retention. Between-group interaction analyses showed sequence-specific increases in functional connectivity during fast learning in the sensorimotor territory of the internal segment of right globus pallidus (GPi), and sequence-specific decreases in right supplementary motor area (SMA) in overall learning. We found that connectivity changes in key regions of the motor network including the superior parietal cortex (SPC) and primary motor cortex (M1) were not a result of sequence-specific learning but were instead linked to motor execution. Our study confirms the sequence-specific role of SMA and GPi that has previously been identified in online task-based learning studies in humans and primates, and extends it to resting state network changes after sequence-specific MSL. Finally, our results shed light on a timing-specific plasticity mechanism between GPi and SMA following MSL.

Role of the Human Rostral Supplementary Motor Area and the Basal Ganglia in Motor Sequence Control: Investigations With H2 15O PET

1998 ◽  
Vol 79 (2) ◽  
pp. 1070-1080 ◽  
Author(s):  
H. Boecker ◽  
A. Dagher ◽  
A. O. Ceballos-Baumann ◽  
R. E. Passingham ◽  
M. Samuel ◽  
...  
Keyword(s):  
Basal Ganglia ◽  
Primary Motor Cortex ◽  
Supplementary Motor Area ◽  
Motor Area ◽  
Anterior Cingulate ◽  
Central Control ◽  
Motor Sequence ◽  
Finger Movements ◽  
Sequence Complexity

Boecker, H., A. Dagher, A. O. Ceballos-Baumann, R. E. Passingham, M. Samuel, K. J. Friston, J.-B. Poline, C. Dettmers, B. Conrad, and D. J. Brooks. Role of the human rostral supplementary motor area and the basal ganglia in motor sequence control: investigations with H2 15O PET. J. Neurophysiol. 79: 1070–1080, 1998. The aim of this study was to investigate the functional anatomy of distributed cortical and subcortical motor areas in the human brain that participate in the central control of overlearned complex sequential unimanual finger movements. On the basis of previous research in nonhuman primates, a principal involvement of basal ganglia (medial premotor loops) was predicted for central control of finger sequences performed automatically. In pertinent areas, a correlation of activation levels with the complexity of a motor sequence was hypothesized. H2 15O positron emission tomography (PET) was used in a group of seven healthy male volunteers [mean age 32.0 ± 10.4 yr] to determine brain regions where levels of regional cerebral blood flow (rCBF) correlated with graded complexity levels of five different key-press sequences. All sequences were overlearned before PET and involved key-presses of fingers II–V of the right hand. Movements of individual fingers were kept constant throughout all five conditions by external pacing at 1-Hz intervals. Positive correlations of rCBF with increasing sequence complexity were identified in the contralateral rostral supplementary motor area (pre-SMA) and the associated pallido-thalamic loop, as well as in right parietal area 7 and ipsilateral primary motor cortex (M1). In contrast, while rCBF in contralateral M1 and and extensive parts of caudal SMA was increased compared with rest during task performance, significant correlated increases of rCBF with sequence complexity were not observed. Inverse correlations of rCBF with increasing sequence complexity were identified in mesial prefrontal-, medial temporal-, and anterior cingulate areas. The findings provide further evidence in humans supporting the notion of a segregation of SMA into functionally distinct subcomponents: although pre-SMA was differentially activated depending on the complexity of a sequence of learned finger movements, such modulation was not detectable in caudal SMA (except the most antero-superior part), implicating a motor executive role. Our observations of complexity-correlated rCBF increases in anterior globus palllidus suggest a specific role for the basal ganglia in the process of sequence facilitation and control. They may act to filter and focus input from motor cortical areas as patterns of action become increasingly complex.

scholarly journals Brain aerobic glycolysis and motor adaptation learning

2016 ◽  
Vol 113 (26) ◽  
pp. E3782-E3791 ◽  
Author(s):  
Benjamin J. Shannon ◽  
Sanjeev Neil Vaishnavi ◽  
Andrei G. Vlassenko ◽  
Joshua S. Shimony ◽  
Jerrel Rutlin ◽  
...  
Keyword(s):  
Synaptic Plasticity ◽  
Functional Connectivity ◽  
Aerobic Glycolysis ◽  
Motor Adaptation ◽  
Resting State Functional Connectivity ◽  
Before And After ◽  
Pet Scans ◽  
The Brain ◽  
Adequate Tissue

Ten percent to 15% of glucose used by the brain is metabolized nonoxidatively despite adequate tissue oxygenation, a process termed aerobic glycolysis (AG). Because of the known role of glycolysis in biosynthesis, we tested whether learning-induced synaptic plasticity would lead to regionally appropriate, learning-dependent changes in AG. Functional MRI (fMRI) before, during, and after performance of a visual–motor adaptation task demonstrated that left Brodmann area 44 (BA44) played a key role in adaptation, with learning-related changes to activity during the task and altered resting-state, functional connectivity after the task. PET scans before and after task performance indicated a sustained increase in AG in left BA 44 accompanied by decreased oxygen consumption. Intersubject variability in behavioral adaptation rate correlated strongly with changes in AG in this region, as well as functional connectivity, which is consistent with a role for AG in synaptic plasticity.

scholarly journals Functional Role of Cerebellar Gamma Frequency in Motor Sequences Learning: a tACS Study

2021 ◽  
Author(s):  
A. Giustiniani ◽  
V. Tarantino ◽  
M. Bracco ◽  
R. E. Bonaventura ◽  
M. Oliveri
Keyword(s):  
Primary Motor Cortex ◽  
Reaction Time Task ◽  
Single Pulse ◽  
Gamma Oscillations ◽  
Corticospinal Excitability ◽  
Oscillatory Activity ◽  
Motor Sequence ◽  
Pseudorandom Sequences ◽  
Gamma Frequency

AbstractAlthough the role of the cerebellum in motor sequences learning is widely established, the specific function of its gamma oscillatory activity still remains unclear. In the present study, gamma (50 Hz)—or delta (1 Hz)—transcranial alternating current stimulation (tACS) was applied to the right cerebellar cortex while participants performed an implicit serial reaction time task (SRTT) with their right hand. The task required the execution of motor sequences simultaneously with the presentation of a series of visual stimuli. The same sequence was repeated across multiple task blocks (from blocks 2 to 5 and from blocks 7 to 8), whereas in other blocks, new/pseudorandom sequences were reproduced (blocks 1 and 6). Task performance was examined before and during tACS. To test possible after-effects of cerebellar tACS on the contralateral primary motor cortex (M1), corticospinal excitability was assessed by examining the amplitude of motor potentials (MEP) evoked by single-pulse transcranial magnetic stimulation (TMS). Compared with delta stimulation, gamma-tACS applied during the SRTT impaired participants’ performance in blocks where the same motor sequence was repeated but not in blocks where the new pseudorandom sequences were presented. Noteworthy, the later assessed corticospinal excitability was not affected. These results suggest that cerebellar gamma oscillations mediate the implicit acquisition of motor sequences but do not affect task execution itself. Overall, this study provides evidence of a specific role of cerebellar gamma oscillatory activity in implicit motor learning.

scholarly journals An Implicit Plan Still Overrides an Explicit Strategy During Visuomotor Adaptation Following Repetitive Transcranial Magnetic Stimulation of the Cerebellum

2020 ◽  
Vol 1 ◽  
Author(s):  
Sarah H. E. M. Voets ◽  
Muriel T. N. Panouilleres ◽  
Ned Jenkinson
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Magnetic Stimulation ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Motor Adaptation ◽  
Visuomotor Adaptation ◽  
Visuomotor Rotation ◽  
Implicit Processes ◽  
Strategy Adaptation ◽  
Implicit Motor

AbstractMotor adaptation is a process by which the brain gradually reduces error induced by a predictable change in the environment, e.g., pointing while wearing prism glasses. It is thought to occur via largely implicit processes, though explicit strategies are also thought to contribute. Research suggests a role of the cerebellum in the implicit aspects of motor adaptation. Using non-invasive brain stimulation, we sought to investigate the involvement of the cerebellum in implicit motor adaptation in healthy participants. Inhibition of the cerebellum was attained through repetitive transcranial magnetic stimulation (rTMS), after which participants performed a visuomotor-rotation task while using an explicit strategy. Adaptation and aftereffects of the TMS group showed no difference in behaviour compared to a Sham stimulation group, therefore this study did not provide any further evidence of a specific role of the cerebellum in implicit motor adaptation. However, our behavioral findings replicate those in the seminal study by Mazzoni and Krakauer (2006).

Cholesterol and its Ayurvedic Complement – Depicting its role in Pathogenesis as well as Management of Diabetes

2017 ◽  
Vol 2 (3) ◽  
Author(s):  
Divya Kajaria
Keyword(s):  
Treatment Modality ◽  
Review Article ◽  
Therapeutic Interventions ◽  
Herbal Remedies ◽  
Natural Properties ◽  
Lipid Balance ◽  
Vast Area

Role of cholesterol in the pathogenesis of diabetes is the emergent are of research with full of potential; it not only open a vast area of therapeutic interventions but also can change the prevailing treatment modality. Ayurveda, the Indian system of medicine materialize the concept of lipocenteric approach for the management of diabetes even thousands of years back. According to Ayurveda, the natural properties of lipid are deranged that causes diabetes. It may prove beneficial to quest the search of herbal remedies that can harmonize the lipid balance and uproot the pathogenesis. In the presenting review article, role of cholesterol in the pathogenesis of diabetes is discussed along with detailed description of Ayurvedic concepts regarding pathogenesis and a brief description of herbal management.

The Role of Resilience in Sexual and Gender Minority Mental Health

2020 ◽  
pp. 428-442
Author(s):  
Dawn M. Szymanski ◽  
Kirsten A. Gonzalez
Keyword(s):  
Mental Health ◽  
Minority Stress ◽  
Quantitative Research ◽  
Social Stigma ◽  
Therapeutic Interventions ◽  
Future Research ◽  
Minority Mental Health ◽  
And Gender ◽  
Structural Levels

Many lesbian, gay, bisexual, transgender, and queer (LGBTQ) persons are able to persevere and flourish despite pervasive social stigma and minority stress based on their sexual orientation and gender identity. This chapter reviews the research on LGBTQ resilience that can occur at individual, interpersonal/family, community, and contextual/structural levels. The authors describe qualitative research that has examined pathways to resilience and positive LGBTQ identity. The authors also review quantitative research on LGBTQ resilience via mediator, moderator, and moderated mediation models. Variables are described that have been found to explain or buffer the links between external and internalized minority stressors and mental health outcomes. The authors review the small but growing body of research that has begun to examine the efficacy of therapeutic interventions aimed at promoting LGBTQ resilience. Limitations are discussed and directions for future research are suggested.

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