All-optical readout and stimulation of cortical activity during optogenetically-triggered motor task in awake mice (Conference Presentation)

2019 ◽  
Author(s):  
Francesco Resta ◽  
Elena Montagni ◽  
Emilia Conti ◽  
Giuseppe de Vito ◽  
Anna Letizia Allegra Mascaro ◽  
...  
Keyword(s):  
Motor Task ◽  
Cortical Activity ◽  
Optical Readout ◽  
All Optical ◽  
Stimulation Of

Absence of increasing cortical fMRI activity volume in response to increasing visceral stimulation in IBS patients

2004 ◽  
Vol 287 (2) ◽  
pp. G425-G435 ◽  
Author(s):  
Harjot Sidhu ◽  
Mark Kern ◽  
Reza Shaker
Keyword(s):  
Cognitive Processes ◽  
Cortical Activity ◽  
Neural Circuitry ◽  
Sensory Function ◽  
Visceral Sensation ◽  
Control Subjects ◽  
Healthy Female ◽  
Irritable Bowel ◽  
Brain Fmri ◽  
Stimulation Of

Cerebral cortical activity associated with perceived visceral sensation represents registration of afferent transduction and cognitive processes related to perception. Abnormalities of gut sensory function can involve either or both of these processes. Cortical registration of subliminal viscerosensory signals represents cerebral cortical activity induced by stimulation of intestinal sensory neurocircuitry without the influence of perception-related cortical activity, whereas those associated with perception represent both neural circuitry and cognitive processes. Our aims were to determine and compare quantitatively cerebral cortical functional magnetic resonance imaging (fMRI) activity in response to subliminal, liminal, and nonpainful supraliminal rectal distension between a group of irritable bowel syndrome (IBS) patients and age/gender-matched controls. Eight female IBS patients and eight age-matched healthy female control subjects were studied using brain fMRI techniques. Three barostat-controlled distension levels were tested: 1) 10 mmHg below perception (subliminal), 2) at perception (liminal), and 3) 10 mmHg above perception (supraliminal). In control subjects, there was a direct relationship between stimulus intensity and cortical activity volumes, ie., the volume of fMRI cortical activity in response to subliminal (3,226 ± 335 μl), liminal (5,751 ± 396 μl), and supraliminal nonpainful stimulation (8,246 ± 624 μl) were significantly different ( P < 0.05). In contrast, in IBS patients this relationship was absent and fMRI activity volumes for subliminal (2,985 ± 332 μl), liminal (2,457 ± 342 μl), and supraliminal nonpainful stimulation (2,493 ± 351 μl) were similar. Additional recruitment of cortical fMRI activity volume in response to increasing stimulation from subliminal to liminal and supraliminal domains is absent in IBS patients, suggesting a difference in the processing of perceived stimulation compared with controls.

scholarly journals Ipsilesional motor cortex activation with high-force unimanual handgrip contractions of the less-affected limb in participants with stroke

2021 ◽  
Author(s):  
Justin W Andrushko ◽  
Layla Gould ◽  
Doug W Renshaw ◽  
Shannon Forrester ◽  
Michael E Kelly ◽  
...  
Keyword(s):  
Brain Activity ◽  
Motor Task ◽  
Brain Activation ◽  
Cortical Activity ◽  
Motor Recovery ◽  
Stroke Recovery ◽  
Inhibitory Influence ◽  
Motor Practice ◽  
Cross Education ◽  
Handgrip Contractions

Stroke is a leading cause of severe disability that often presents with unilateral motor impairment. Conventional rehabilitation approaches focus on motor practice of the affected limb and aim to suppress brain activity in the contralesional hemisphere to facilitate ipsilesional hemispheric neuroplasticity subserving motor recovery. Previous research has also demonstrated that exercise of the less-affected limb can promote motor recovery of the affected limb through the interlimb transfer of the trained motor task, termed cross-education. One of the leading theories for cross-education proposes that the interlimb transfer manifests from ipsilateral cortical activity during unimanual motor tasks, and that this ipsilateral cortical activity results in motor related neuroplasticity giving rise to contralateral improvements in motor performance. Conversely, exercise of the less-affected limb promotes contralesional brain activity which is typically viewed as contraindicated in stroke recovery due to the interhemispheric inhibitory influence onto the ipsilesional hemisphere. High-force unimanual handgrip contractions are known to increase ipsilateral brain activation in control participants, but it remains to be determined if this would be observed in participants with stroke. Therefore, this study aimed to determine how parametric increases in handgrip force during repeated contractions with the less-affected limb impacts brain activity bilaterally in participants with stroke and in a cohort of neurologically intact controls. In this study, higher force contractions were found to increase brain activation in the ipsilesional/ipsilateral hemisphere in both groups (p = .002), but no between group differences were observed. These data suggest that high-force exercise with the less-affected limb may promote ipsilesional cortical plasticity to promote motor recovery of the affected-limb in participants with stroke.

Modulation of synaptic transmission at Ia-afferent connections on motoneurons during high-frequency afferent stimulation: dependence on motor task

1991 ◽  
Vol 65 (6) ◽  
pp. 1313-1320 ◽  
Author(s):  
H. R. Koerber ◽  
L. M. Mendell
Keyword(s):  
High Frequency ◽  
Frequency Control ◽  
Motor Task ◽  
Low Frequency ◽  
Medial Gastrocnemius ◽  
High Frequency Stimulation ◽  
Lateral Gastrocnemius ◽  
Low Frequency Stimulation ◽  
Frequency Stimulation ◽  
Stimulation Of

1. Monosynaptic excitatory postsynaptic potentials (EPSPs) were evoked in medial gastrocnemius motoneurons by maximal group Ia stimulation of the heteronymous lateral gastrocnemius-soleus nerve in anesthetized cats. Three different patterns of high-frequency stimulation were delivered to the nerve, and the EPSPs were averaged in register (1, 2, . . ., n) for each. 2. One pattern ("Burst") consisted of 32 shocks delivered every 2 s at an interstimulus interval of 6 ms (167 Hz). The second pattern ("Stepping") was a frequency-modulated burst of 52 shocks derived from a recording of a spindle during stepping and was delivered every 2 s. The third pattern ("Paw Shake") was from an extensor spindle afferent recorded during rapid paw shake and was delivered in groups of six bursts with an interburst interval of 75 ms and a 3-s pause between groups of six bursts. The EPSPs in each burst were averaged in register (1, 2, . . ., n) so that the relative amplitude of each EPSP in the burst could be ascertained. The EPSP produced by low-frequency stimulation of the nerve (18 Hz) was also recorded for each motoneuron. 3. The initial EPSP in most bursts was larger than the EPSP measured as a result of low-frequency stimulation. This potentiation, defined as the ratio of the amplitude of the initial EPSP of the response to that of the low-frequency control, was found to vary systematically as a function of amplitude of the control EPSP as well as the stimulus paradigm used.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Bimanual digit training improves right-hand dexterity in older adults by reactivating declined ipsilateral motor-cortical inhibition

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Eiichi Naito ◽  
Tomoyo Morita ◽  
Satoshi Hirose ◽  
Nodoka Kimura ◽  
Hideya Okamoto ◽  
...  
Keyword(s):  
Older Adults ◽  
Motor Task ◽  
Cortical Activity ◽  
Cortical Inhibition ◽  
Older Individuals ◽  
Inhibitory System ◽  
Finger Dexterity ◽  
Right Hand ◽  
Hand Dexterity ◽  
Motor Cortical

AbstractImproving deteriorated sensorimotor functions in older individuals is a social necessity in a super-aging society. Previous studies suggested that the declined interhemispheric sensorimotor inhibition observed in older adults is associated with their deteriorated hand/finger dexterity. Here, we examined whether bimanual digit exercises, which can train the interhemispheric inhibitory system, improve deteriorated hand/finger dexterity in older adults. Forty-eight healthy, right-handed, older adults (65–78 years old) were divided into two groups, i.e., the bimanual (BM) digit training and right-hand (RH) training groups, and intensive daily training was performed for 2 months. Before and after the training, we evaluated individual right hand/finger dexterity using a peg task, and the individual state of interhemispheric sensorimotor inhibition by analyzing ipsilateral sensorimotor deactivation via functional magnetic resonance imaging when participants experienced a kinesthetic illusory movement of the right-hand without performing any motor tasks. Before training, the degree of reduction/loss of ipsilateral motor-cortical deactivation was associated with dexterity deterioration. After training, the dexterity improved only in the BM group, and the dexterity improvement was correlated with reduction in ipsilateral motor-cortical activity. The capability of the brain to inhibit ipsilateral motor-cortical activity during a simple right-hand sensory-motor task is tightly related to right-hand dexterity in older adults.

scholarly journals All-optical recording and stimulation of retinal neurons in vivo in retinal degeneration mice

PLoS ONE ◽  
2018 ◽  
Vol 13 (3) ◽  
pp. e0194947 ◽  
Author(s):  
Soon Keen Cheong ◽  
Jennifer M. Strazzeri ◽  
David R. Williams ◽  
William H. Merigan
Keyword(s):  
Retinal Degeneration ◽  
Optical Recording ◽  
Retinal Neurons ◽  
All Optical ◽  
Stimulation Of

scholarly journals All‐Optical and Label‐Free Stimulation of Action Potentials in Neurons and Cardiomyocytes by Plasmonic Porous Metamaterials

2021 ◽  
pp. 2100627
Author(s):  
Giulia Bruno ◽  
Giovanni Melle ◽  
Andrea Barbaglia ◽  
Giuseppina Iachetta ◽  
Rustamzhon Melikov ◽  
...  
Keyword(s):  
Action Potentials ◽  
Label Free ◽  
All Optical ◽  
Stimulation Of
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