Learning-induced Dependence of Neuronal Activity in Primary Motor Cortex on Motor Task Condition

1. Single-cell activity was recorded from three different motor areas in the cerebral cortex: the primary motor cortex (MI), supplementary motor area (SMA), and premotor cortex (PM). 2. Three monkeys (Macaca fuscata) were trained to perform a sequential motor task in two different conditions. In one condition (visually triggered task, VT), they reached to and touched three pads placed in a front panel by following lights illuminated individually from behind the pads. In the other condition (internally guided task, IT), they had to remember a predetermined sequence and press the three pads without visual guidance. In a transitional phase between the two conditions, the animals learned to memorize the correct sequence. Auditory instruction signals (tones of different frequencies) told the animal which mode it was in. After the instruction signals, the animals waited for a visual signal that triggered the first movement. 3. Neuronal activity was analyzed during three defined periods: delay period, premovement period, and movement period. Statistical comparisons were made to detect differences between the two behavioral modes with respect to the activity in each period. 4. Most, if not all, of MI neurons exhibited similar activity during the delay, premovement, and movement periods, regardless of whether the sequential motor task was visually guided or internally determined. 5. More than one-half of the SMA neurons were preferentially or exclusively active in relation to IT during both the premovement (55%) and movement (65%) periods. In contrast, PM neurons were more active (55% and 64% during the premovement and movement periods) in VT. 6. During the instructed-delay period, a majority of SMA neurons exhibited preferential or exclusive relation to IT whereas the activity in PM neurons was observed equally in different modes. 7. Two types of neurons exhibiting properties of special interest were observed. Sequence-specific neurons (active in a particular sequence only) were more common in SMA, whereas transition-specific neurons (active only at the transitional phase) were more common in PM. 8. Although a strict functional dichotomy is not acceptable, these observations support a hypothesis that the SMA is more related to IT, whereas PM is more involved in VT. 9. Some indications pointing to a functional subdivision of PM are obtained.

Download Full-text

Abstract TP441: Neurovascular Coupling is Impaired in Cerebral Amyloid Angiopathy

Stroke ◽

10.1161/str.44.suppl_1.atp441 ◽

2013 ◽

Vol 44 (suppl_1) ◽

Author(s):

Stefano Peca ◽

Cheryl R McCreary ◽

Emily Donaldson ◽

Karla Sanchez ◽

Anna Charlton ◽

...

Keyword(s):

White Matter ◽

Motor Cortex ◽

Primary Motor Cortex ◽

White Matter Lesion ◽

Motor Task ◽

Neurovascular Coupling ◽

Occipital Lobe ◽

Amyloid Angiopathy ◽

Bold Response ◽

Cerebral Amyloid

Introduction: Cerebral amyloid angiopathy (CAA) is marked by accumulation of vascular beta-amyloid which is toxic to smooth muscle cells. An animal study and a pilot study in humans suggest decreased vasodilation in CAA. We studied patients with CAA and matched controls to determine whether neurovascular coupling is impaired in CAA. Methods: Patients with CAA and controls underwent task-related fMRI with a visual task (viewing a flashing alternating checkerboard pattern) or a motor task (tapping the fingers of the dominant hand) using a block design, and visual evoked potentials (VEPs). CAA patients were diagnosed by Boston criteria and had normal corrected visual acuity, no visual field deficits and no paresis of the dominant arm. Controls were recruited by community advertising and were matched by gender and age (±5 years) to CAA cases. Results: Eighteen CAA patients (12 M, 6F; 72±7 yrs) and eighteen controls (12 M, 6F; 70±7 yrs) were studied. For the visual task, CAA patients had reduced activity in the occipital lobe (Figure) and lower amplitude of the BOLD response vs. controls (28% reduced, p=0.005). By contrast, for the motor task CAA patients had a similar response of the primary motor cortex vs. controls (9.6% reduced BOLD response, p=0.53). VEP P100 latencies and amplitudes did not differ between CAA and controls (p=0.49 and p=0.74). Lower visual cortex BOLD amplitudes were correlated with greater white matter lesion volumes in CAA (r=-0.66, p=0.003). Conclusions: Neurovascular coupling is impaired in the occipital lobe in CAA. BOLD signal amplitudes are reduced despite normal evoked potentials, suggesting impaired vasodilation. The association with white matter lesion volume raises the possibility that impaired vasodilation may be involved in the pathogenesis of these lesions. BOLD responses in the primary motor cortex in CAA were not reduced, likely reflecting the known posterior predominance of CAA with lesser involvement of the frontal lobe.

Download Full-text

Altered Primary Motor Cortex Neuronal Activity in a Rat Model of Harmaline-Induced Tremor During Thalamic Deep Brain Stimulation

Frontiers in Cellular Neuroscience ◽

10.3389/fncel.2019.00448 ◽

2019 ◽

Vol 13 ◽

Author(s):

Jihyun Lee ◽

Su-youne Chang

Keyword(s):

Deep Brain Stimulation ◽

Motor Cortex ◽

Neuronal Activity ◽

Brain Stimulation ◽

Rat Model ◽

Primary Motor Cortex ◽

Deep Brain

Download Full-text

Neuronal activity in the primate supplementary motor area and the primary motor cortex in relation to spatio-temporal bimanual coordination

Somatosensory & Motor Research ◽

10.1080/08990229870709 ◽

1998 ◽

Vol 15 (4) ◽

pp. 287-308 ◽

Cited By ~ 71

Author(s):

I. KERMADI ◽

TEMPIN CALCIATI ◽

E. M. ROUILLER

Keyword(s):

Motor Cortex ◽

Neuronal Activity ◽

Bimanual Coordination ◽

Primary Motor Cortex ◽

Supplementary Motor Area ◽

Motor Area ◽

Spatio Temporal

Download Full-text

Motor cortex excitability and fatigue in multiple sclerosis: a transcranial magnetic stimulation study

Multiple Sclerosis Journal ◽

10.1191/1352458505ms1163oa ◽

2005 ◽

Vol 11 (3) ◽

pp. 316-321 ◽

Cited By ~ 82

Author(s):

J Liepert ◽

D Mingers ◽

C Heesen ◽

T Bäumer ◽

C Weiller

Keyword(s):

Multiple Sclerosis ◽

Transcranial Magnetic Stimulation ◽

Motor Cortex ◽

Magnetic Stimulation ◽

Primary Motor Cortex ◽

Motor Task ◽

Time Interval ◽

Membrane Excitability ◽

Motor Cortex Excitability ◽

Fatigue Severity

We investigated electrophysiological correlates of fatigue in patients with multiple sclerosis (MS). Transcranial magnetic stimulation (TMS) was used to explore motor excitability in three groups of subjects: MS patients with fatigue (MS-F), MS patients without fatigue (MS-NF) and healthy control subjects. All participants had to perform a fatiguing hand-grip exercise. TMS was performed prior to and after the exercise. Prior to the motor task, MS-F patients had less inhibition in the primary motor cortex compared to both other groups. Postexercise, intracortical inhibition was still reduced in the MS-F patients compared to the MS-NF patients. In MS-F patients the postexercise time interval for normalization of the motor threshold was correlated with the fatigue severity. We conclude that MS patients with fatigue have an impairment of inhibitory circuits in their primary motor cortex. The results also indicate that fatigue severity is associated with an exercise-induced reduction of membrane excitability.

Download Full-text

Neuronal activity in primary motor cortex associated with locomotor movements of an unrestrained Japanese monkey

Neuroscience Research ◽

10.1016/j.neures.2010.07.1669 ◽

2010 ◽

Vol 68 ◽

pp. e376

Author(s):

Katsumi Nakajima ◽

Futoshi Mori ◽

Akira Murata ◽

Masahiko Inase

Keyword(s):

Motor Cortex ◽

Neuronal Activity ◽

Primary Motor Cortex ◽

Japanese Monkey

Download Full-text

Laterality of Movement-Related Activity Reflects Transformation of Coordinates in Ventral Premotor Cortex and Primary Motor Cortex of Monkeys

Journal of Neurophysiology ◽

10.1152/jn.00149.2007 ◽

2007 ◽

Vol 98 (4) ◽

pp. 2008-2021 ◽

Cited By ~ 14

Author(s):

Kiyoshi Kurata

Keyword(s):

Motor Cortex ◽

Neuronal Activity ◽

Primary Motor Cortex ◽

Premotor Cortex ◽

Visuomotor Transformation ◽

Related Activity ◽

Reaching Task ◽

Ventral Premotor Cortex ◽

Cortical Motor ◽

Target Locations

The ventral premotor cortex (PMv) and the primary motor cortex (MI) of monkeys participate in various sensorimotor integrations, such as the transformation of coordinates from visual to motor space, because the areas contain movement-related neuronal activity reflecting either visual or motor space. In addition to relationship to visual and motor space, laterality of the activity could indicate stages in the visuomotor transformation. Thus we examined laterality and relationship to visual and motor space of movement-related neuronal activity in the PMv and MI of monkeys performing a fast-reaching task with the left or right arm, toward targets with visual and motor coordinates that had been dissociated by shift prisms. We determined laterality of each activity quantitatively and classified it into four types: activity that consistently depended on target locations in either head-centered visual coordinates (V-type) or motor coordinates (M-type) and those that had either differential or nondifferential activity for both coordinates (B- and N-types). A majority of M-type neurons in the areas had preferences for reaching movements with the arm contralateral to the hemisphere where neuronal activity was recorded. In contrast, most of the V-type neurons were recorded in the PMv and exhibited less laterality than the M-type. The B- and N-types were recorded in the PMv and MI and exhibited intermediate properties between the V- and M-types when laterality and correlations to visual and motor space of them were jointly examined. These results suggest that the cortical motor areas contribute to the transformation of coordinates to generate final motor commands.

Download Full-text