ABSTRACT
Objective:To apply functional near-infrared spectroscopy (fNIRS) to analyze brain activity pattern of bilateral sensorimotor cortex (SMC) and premotor cortex (PMC) during complex dominant and non-dominant hand movement in healthy subjects. Methods:From August to December, 2019, 15 right-handed healthy residents were recruited. The block designed grip-release task was used in the subjects, and detected oxyhemoglobin and deoxyhemoglobin concentration with fNIRS to analyze the activation of bilateral SMC, PMC and prefontal cortex in term of activation channels and intensity. Results:For the oxyhemoglobin concentration, the number of activated channels was the same in both hemispheres during right (dominant) hand movement, and the activation of left SMC was stronger (P < 0.05); however, more channels were activated in the right hemisphere during left (non-dominant) hand movement, and the activation of right SMC was stronger (P < 0.05). For the deoxyhemoglobin concentration, more channels were activated in the contralateral hemisphere during either dominant or non-dominant hand movement, and the activation of left SMC, Channel 12 (left PMC) and Channel 26 (right PMC) were stronger during right (dominant) hand movement (P < 0.05). Conclusion:It is feasible to use fNIRS to study the activation of hand movement related brain regions during complex movement of dominant and non-dominant hand, especially with the results of oxyhemoglobin concentration.
ABSTRACT
Objective To assess differences in brain activation between active and passive movement of the right hand using blood oxygen level-dependent functional magnetic resonance imaging (BOLD-fMRI). Methods Nine healthy adult right handed volunteers were studied. fMRI was performed with active and passive finger-to-finger movement. Results Right hand active and passive movement produced significant activation in the contralateral sensorimotor cortex ( SMC ), the contralateral premotor cortex ( PMC ), bilaterally in the supplementary motor area (SMA) and in the ipsilateral cerebellum. The activated brain areas were centered on the contralateral SMC and PMC and located more forward during active movement than during passive movement. The contralateral SMC was the most strongly and the most frequently activated brain area. The contralateral posterior parietal cortex (PPC) was less relevant to the hand movements. Unlike active movement, passivemovement activated more areas in the posterior central gyrus than in the anterior central gyrus. Conclusions Both active and passive movement significantly activate the brain areas which are responsible for hand movement, but there are some differences in the locations of the cortex areas activated and in the incidence activation except in the contralateral SMC.
ABSTRACT
This study examined and compared the immunocytochemical distribution of the two calcium-binding proteins calbindin D-28k and parvalbumin in the sensory and motor cortex of the cat. In this experimental animal, calcium-binding protein calbindin D-28k immunoreactive neurons were mainly found many pyramidal cells distributed in layers 2 and 3 of the two cortical areas. Calbindin D-28k neuropil labeling was heaviest in layers 1 to 3. In contrast to parvalbumin, we found only minor differences in distribution, size and mor-phology of calbindin D-28k cell body or neuropil staining in the two cortical areas. Parvalbumin- immunoreactive cells were in all layers cortex except layer 1 and reached their peak density in the middle layers. The two cortical areas differed markedly in number, cell size and morphology of immunoreactive cells. Parvalbumin positive cells were more than twice as numerous in the two cortical areas compared to the calbindin D-28k positive cells. Calbindin D-28k and parvalbumin-immunoreactive somata were round, oval, spindle and polygonal in shape, and the positive neurons were unipolar, bipolar,multipolar and horizontal in shape. The diameters of the somata of the two positive neurons were 15~20 micrometer. Also, two positive dendrites were considerably densely arrayed in arborization.
Subject(s)
Animals , Cats , Calbindins , Calcium-Binding Proteins , Cell Count , Dendrites , Motor Cortex , Neurons , Neuropil , Pyramidal CellsABSTRACT
The motor evoked potentials (MEPs) have been advocated as a method of monitoring the integrity of spinal efferent pathways in various injury models of the central nervous system. However, there were many disputes about origin sites of MEPs generated by transcranial electrical stimulation. The purpose of present study was to investigate the effect of major extrapyramidal motor nuclei such as lateral vestibular nucleus (VN) and medullary reticular nucleus (mRTN) on any components of the MEPs in adult Sprague-Dawley rats. MEPs were evoked by electrical stimulation of the right sensorimotor cortex through a stainless steel screw with 0.5mm in diameter, and recorded epidurally at T9 - T10 spinal cord levels by using a pair of teflon-coated stainless steel wire electrodes with 1mm exposed tip. In order to inject lidocaine and make a lesion, insulated long dental needle with noninsulated tips were placed stereotaxically in VN and mRTN. Lidocaine of 2~3 mul was injected into either VN or mRTN. The normal MEPs were composed of typical four reproducible waves; P1, P2, P3, P4. The first wave (P1) was shown at a mean latency of 1.2 ms, corresponding to a conduction velocity of 67.5 m/sec. The latencies of MEP were shortened and the amplitudes were increased as stimulus intensity was increased. The amplitudes of P1 and P2 were more decreased among 4 waves of MEPs after lidocaine microinjection into mRTN. Especially, the amplitude of P1 was decreased by 50% after lidocaine microinjection into bilateral mRTN. On the other hand, lidocaine microinjection into VN reduced the amplitudes of P3 and P4 than other MEP waves. However, the latencies of MEPs were not changed by lidocaine microinjection into either VN or mRTN. These results suggest that the vestibular and reticular nuclei contribute to partially different role in generation of MEPs elicited by transcranial electrical stimulation.