Focal Photothrombotic Lesion of the Rat Motor Cortex Increases BDNF Levels in Motor-Sensory Cortical Areas Not Accompanied by Recovery of Forelimb Motor Skills

2007 ◽  
Vol 24 (8) ◽  
pp. 1362-1377 ◽  
Author(s):  
Dorota Sulejczak ◽  
Ewelina Ziemlińska ◽  
Julita Czarkowska-Bauch ◽  
Ewa Nosecka ◽  
Ryszard Strzalkowski ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Motor Skills ◽  
Cortical Areas

scholarly journals Dopamine D2 receptors modulate intrinsic properties and synaptic transmission of parvalbumin interneurons in the mouse primary motor cortex

2019 ◽  
Author(s):  
Jérémy Cousineau ◽  
Léa Lescouzères ◽  
Anne Taupignon ◽  
Lorena Delgado-Zabalza ◽  
Emmanuel Valjent ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Synaptic Transmission ◽  
Motor Skills ◽  
Primary Motor Cortex ◽  
Pyramidal Neurons ◽  
D2 Receptors ◽  
Receptor Subtypes ◽  
Parvalbumin Interneurons ◽  
Layer V ◽  
Gabaergic Synaptic Transmission

AbstractDopamine (DA) plays a crucial role in the control of motor and higher cognitive functions such as learning, working memory and decision making. The primary motor cortex (M1), which is essential for motor control and the acquisition of motor skills, receives dopaminergic inputs in its superficial and deep layers from the midbrain. However, the precise action of DA and DA receptor subtypes on the cortical microcircuits of M1 remains poorly understood. The aim of this work was to investigate how DA, through the activation of D2 receptors (D2R), modulates the cellular and synaptic activity of M1 parvalbumin-expressing interneurons (PVINs) which are crucial to regulate the spike output of pyramidal neurons (PNs). By combining immunofluorescence, ex vivo electrophysiology, pharmacology and optogenetics approaches, we show that D2R activation increases neuronal excitability of PVINs and GABAergic synaptic transmission between PVINs and PNs in layer V of M1. Our data reveal a mechanism through which cortical DA modulates M1 microcircuitry and might participate in the acquisition of motor skills.Significance StatementPrimary motor cortex (M1), which is a region essential for motor control and the acquisition of motor skills, receives dopaminergic inputs from the midbrain. However, precise action of dopamine and its receptor subtypes on specific cell types in M1 remained poorly understood. Here, we demonstrate in M1 that dopamine D2 receptors (D2R) are present in parvalbumin interneurons (PVINs) and their activation increases the excitability of the PVINs, which are crucial to regulate the spike output of pyramidal neurons (PNs). Moreover the activation of the D2R facilitates the GABAergic synaptic transmission of those PVINs on layer V PNs. These results highlight how cortical dopamine modulates the functioning of M1 microcircuit which activity is disturbed in hypo- and hyperdopaminergic states.

scholarly journals Motor cortical inactivation reduces the gain of kinematic primitives in mice performing a hold-still center-out reach task

2018 ◽  
Author(s):  
Tejapratap Bollu ◽  
Samuel C. Whitehead ◽  
Nikil Prasad ◽  
Jackson Walker ◽  
Nitin Shyamkumar ◽  
...  
Keyword(s):  
Motor Cortex ◽  
High Precision ◽  
Closed Loop ◽  
Building Blocks ◽  
Kinematic Parameter ◽  
Cortical Areas ◽  
Freely Moving ◽  
Motor Cortical ◽  
Peak Speed ◽  
Contralateral Motor

SUMMARYMotor sequences are constructed from primitives, hypothesized building blocks of movement, but mechanisms of primitive generation remain unclear. Using automated homecage training and a novel forelimb sensor, we trained freely-moving mice to initiate forelimb sequences with clearly resolved submillimeter-scale micromovements followed by millimeter-scale reaches to learned spatial targets. Hundreds of thousands of trajectories were decomposed into millions of kinematic primitives, while closed-loop photoinhibition was used to test roles of motor cortical areas. Inactivation of contralateral motor cortex reduced primitive peak speed but, surprisingly, did not substantially affect primitive direction, initiation, termination, or complexity, resulting in isomorphic, spatially contracted trajectories that undershot targets. Our findings demonstrate separable loss of a single kinematic parameter, speed, and identify conditions where loss of cortical drive reduces the gain of motor primitives but does not affect their generation, timing or direction. The combination of high precision forelimb sensing with automated training and neural manipulation provides a system for studying how motor sequences are constructed from elemental building blocks.

Modulation of Cortical Activity by High-Frequency Whole-Body Vibration Exercise: An fNIRS Study

2019 ◽  
Vol 28 (7) ◽  
pp. 665-670 ◽  
Author(s):  
Dong-Sung Choi ◽  
Hwang-Jae Lee ◽  
Yong-II Shin ◽  
Ahee Lee ◽  
Hee-Goo Kim ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Whole Body Vibration ◽  
Hemoglobin Concentration ◽  
Cortical Activity ◽  
Cortical Activation ◽  
Whole Body ◽  
Body Vibration ◽  
Cortical Areas ◽  
Vibration Condition

Context: Whole-body vibration (WBV) has shown many positive effects on the human body in rehabilitation and clinical settings in which vibration has been used to elicit muscle contractions in spastic and paretic muscles. Objective: The purpose of this study was to investigate whether WBV exercise (WBVe) differently modulates the cortical activity associated with motor and prefrontal function based on its frequency. Methods: A total of 18 healthy male adults (mean age: 25.3 [2.4] y) participated in this study and performed WBVe (Galileo Advanced plus; Novotec Medical, Pforzheim, Germany) under 3 different vibration frequency conditions (4-mm amplitude with 10-, 20-, and 27-Hz frequencies) and a control condition (0-mm amplitude with 0-Hz frequency). Each condition consisted of 2 alternating tasks (squatting and standing) every 30 seconds for 5 repetitions. All subjects performed the 4 conditions in a randomized order. Main Outcome Measure: Cortical activation during WBVe was measured by relative changes in oxygenated hemoglobin concentration over the primary motor cortex, premotor cortex, supplementary motor area, and prefrontal and somatosensory cortices using functional near-infrared spectroscopy. Results: Oxygenated hemoglobin concentration was higher during the 27-Hz vibration condition than the control and 10-Hz vibration conditions. Specifically, these changes were pronounced in the bilateral primary motor cortex (P < .05) and right prefrontal cortex (P < .05). In contrast, no significant changes in oxygenated hemoglobin concentration were observed in any of the cortical areas during the 10-Hz vibration condition compared with the control condition. Conclusion: This study provides evidence that the motor network and prefrontal cortical areas of healthy adult males can be activated by 27-Hz WBVe. However, WBVe at lower frequencies did not induce significant changes in cortical activation.

scholarly journals Two Phases of Interhemispheric Inhibition between Motor Related Cortical Areas and the Primary Motor Cortex in Human

2008 ◽  
Vol 19 (7) ◽  
pp. 1654-1665 ◽  
Author(s):  
Z. Ni ◽  
C. Gunraj ◽  
A. J. Nelson ◽  
I.-J. Yeh ◽  
G. Castillo ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Interhemispheric Inhibition ◽  
Cortical Areas ◽  
Two Phases

scholarly journals Neural Substrates of Practice Structure That Support Future Off-Line Learning

2009 ◽  
Vol 102 (4) ◽  
pp. 2462-2476 ◽  
Author(s):  
Nicholas F. Wymbs ◽  
Scott T. Grafton
Keyword(s):  
Motor Cortex ◽  
Motor Skills ◽  
Primary Motor Cortex ◽  
Neural Substrates ◽  
Skill Learning ◽  
Opposite Pattern ◽  
Practice Schedule ◽  
Random Schedule ◽  
Subcortical Regions ◽  
Equivalent Motor

Off-line learning is facilitated when motor skills are acquired under a random practice schedule and retention suffers when a similar set of motor skills are practiced under a blocked schedule. The current study identified the neural correlates of a random training schedule while participants learned a set of four-element finger sequences using their nondominant hand during functional magnetic resonance imaging. A go/no go task was used to separately probe brain areas supporting sequence preparation and production. By the end of training, the random practice schedule, relative to the block schedule, recruited a broad premotor–parietal network as well as sensorimotor and subcortical regions during both preparation and production trials, despite equivalent motor performance. Longitudinal analysis demonstrated that preparation-related activity under a random schedule remained stable or increased over time. The blocked schedule showed the opposite pattern. Across individual subjects, successful skill retention was correlated with greater activity at the end of training in the ipsilateral left motor cortex, for both preparation and production. This is consistent with recent evidence that attributes off-line learning to training-related processing within primary motor cortex. These results reflect the importance of an overlooked aspect of motor skill learning. Specifically, how trials are organized during training—with a random schedule—provides an effective basis for the formation of enduring motor memories, through enhanced engagement of core regions involved in the active preparation and implementation of motor programs.

Patterns of functional magnetic resonance imaging activation in association with structural lesions in the rolandic region: a classification system

2001 ◽  
Vol 94 (6) ◽  
pp. 946-954 ◽  
Author(s):  
Alexandre C. Carpentier ◽  
R. Todd Constable ◽  
Michael J. Schlosser ◽  
Alain de Lotbinière ◽  
Joseph M. Piepmeier ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Motor Cortex ◽  
Motor Skills ◽  
Classification Scheme ◽  
Surgical Intervention ◽  
Functional Magnetic Resonance ◽  
Content Type ◽  
Rolandic Region ◽  
Fine Print

Object. Functional magnetic resonance (fMR) imaging of the motor cortex is a potentially powerful tool in the preoperative planning of surgical procedures in and around the rolandic region. Little is known about the patterns of fMR imaging activation associated with various pathological lesions in that region or their relation to motor skills before surgical intervention. Methods. Twenty-two control volunteers and 44 patients whose pathologies included arteriovenous malformations (AVMs; 16 patients), congenital cortical abnormalities (11 patients), and tumors (17 patients) were studied using fMR imaging and a hand motor task paradigm. Activation maps were constructed for each participant, and changes in position or amplitude of the motor activation on the lesion side were compared with the activation pattern obtained in the contralateral hemisphere. A classification scheme of plasticity (Grades 1–6) based on interhemispheric pixel asymmetry and displacement of activation was used to compare maps between patients, and relative to hand motor dexterity and/or weakness. There was 89.4% interobserver agreement on classification of patterns of fMR imaging activation. Displacement of activation by mass effect was more likely with tumors. Cortical malformations offer a much higher functional reorganization than AVMs or tumors. High-grade plasticity is recruited to compensate for severe motor impairment. Conclusions. Pattern modification of fMR imaging activation can be systematized in a classification of motor cortex plasticity. This classification has shown good correlation among grading, brain lesions, and motor skills. This proposal of a classification scheme, in addition to facilitating data collection and processing from different institutions, is well suited for comparing risks associated with surgical intervention and patterns of functional recovery in relation to preoperative fMR imaging categorization. Such studies are underway at the authors' institution.

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