scholarly journals Distinct Contributions of Whisker Sensory Cortex and Tongue-Jaw Motor Cortex in a Goal-Directed Sensorimotor Transformation

Neuron ◽  
2019 ◽  
Vol 103 (6) ◽  
pp. 1034-1043.e5 ◽  
Author(s):  
Johannes M. Mayrhofer ◽  
Sami El-Boustani ◽  
Georgios Foustoukos ◽  
Matthieu Auffret ◽  
Keita Tamura ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Sensory Cortex ◽  
Sensorimotor Transformation

Brain adaptation to chronic hypobaric hypoxia in rats

1992 ◽  
Vol 72 (6) ◽  
pp. 2238-2243 ◽  
Author(s):  
J. C. LaManna ◽  
L. M. Vendel ◽  
R. M. Farrell
Keyword(s):  
Blood Flow ◽  
Motor Cortex ◽  
Microvessel Density ◽  
Hypobaric Hypoxia ◽  
Regional Blood Flow ◽  
Oxygen Availability ◽  
Sensory Cortex ◽  
Hypoxic Exposure ◽  
Normal Brain ◽  
Tissue Po2

Rats were exposed to hypobaric hypoxia (0.5 atm) for up to 3 wk. Hypoxic rats failed to gain weight but maintained normal brain water and ion content. Blood hematocrit was increased by 48% to a level of 71% after 3 wk of hypoxia compared with littermate controls. Brain blood flow was increased by an average of 38% in rats exposed to 15 min of 10% normobaric oxygen and by 23% after 3 h but was not different from normobaric normoxic rats after 3 wk of hypoxia. Sucrose space, as a measure of brain plasma volume, was not changed under any hypoxic conditions. The mean brain microvessel density was increased by 76% in the frontopolar cerebral cortex, 46% in the frontal motor cortex, 54% in the frontal sensory cortex, 65% in the parietal motor cortex, 68% in the parietal sensory cortex, 68% in the hippocampal CA1 region, 57% in the hippocampal CA3 region, 26% in the striatum, and 56% in the cerebellum. The results indicate that hypoxia elicits three main responses that affect brain oxygen availability. The acute effect of hypoxia is an increase in regional blood flow, which returns to control levels on continued hypoxic exposure. Longer-term effects of continued moderate hypoxic exposure are erythropoiesis and a decrease in intercapillary distance as a result of angiogenesis. The rise in hematocrit and the increase in microvessel density together increase oxygen availability to the brain to within normal limits, although this does not imply that tissue PO2 is restored to normal.

Anatomical analysis of ventrolateral thalamic input to primate motor cortex

1976 ◽  
Vol 39 (5) ◽  
pp. 1020-1031 ◽  
Author(s):  
P. L. Strick
Keyword(s):  
Motor Cortex ◽  
Retrograde Transport ◽  
Sensory Cortex ◽  
Central Sulcus ◽  
Thalamic Neurons ◽  
Thalamic Input ◽  
Continuous Slab ◽  
Ventrolateral Thalamus ◽  
Point To Point ◽  
Somatic Sensory Cortex

1. The origin and topographical organization of input to the arm area of the primate motor cortex from the ventrolateral thalamus were examined using the method of retrograde transport of horseradish peroxidase (HRP). 2. A thin, continuous slab of labeled neurons was found in the ventrolateral thalamus followingmultiple injections of HRP into the arm area of the motor cortex. The slab of labeled neurons was flanked, medially and laterally, by groups of unlabeled neurons. 3. The origin of ventrolateral thalamic input was more extensive than previously thought. Labeled neurons were found from A10.0 to A6.0 and occurred in three ventolateral thalamic subdivisions: ventralis lateralis pars oralis (VLo), ventralis lateralis pars caudalis (VLc), and ventralis posterior lateralis pars oralis (VPLo). For simplicity this region containing labeled neurons has been termed the ventrolateral thalamic (VL) arm area. 4. Injections of HRP into the somatic sensory cortex indicated that the thalamic regions which project to the somatic sensory cortex are separate from the VL arm area. 5. The distribution of labeled neurons following single injections of HRP into different regions of the motor cortex arm area indicated that the VL arm area is topographically organized, particularly its caudal part. Ventral regions of the VL arm area were labeled following HRP injections into motor cortex regions adjacent to the central sulcus where the representation of largely distal musculature is localized. Dorsal regions of the VL arm area were labeled following HRP injections into motor cortex regions more rostral to the central sulcus where the representation of more proximal musculature is localized. 6. A larger region of the VL arm area was labeled following HRP injections adjacent to the central sulcus than following the more rostral motor cortex injections. This suggests that, like the arm area of the motor cortex, more of the VL arm area is allotted to the representation of distal than proximal musculature. 7. Following very small cortical HRP injections, isolated labeled thalamic neurons were diffusely scattered throughout a 3-mm rostrocaudal extent of the VL arm area. In addition, a small focal cluster of labeled thalamic neurons was also seen. The labeled cluster was limited to 0.5 mm rostrocaudally and 300 mum in width. The focal distribution of labeled thalamic neurons suggests that aspects of a point to point organization may exist in the connection between VL and the motor cortex arm area.

A further examination of effects of cortical stimulation on primate spinothalamic tract cells

1983 ◽  
Vol 49 (2) ◽  
pp. 424-441 ◽  
Author(s):  
R. P. Yezierski ◽  
K. D. Gerhart ◽  
B. J. Schrock ◽  
W. D. Willis
Keyword(s):  
Motor Cortex ◽  
Sensorimotor Cortex ◽  
Dynamic Range ◽  
Cortical Stimulation ◽  
Cortical Inhibition ◽  
Sensory Cortex ◽  
High Threshold ◽  
Spinothalamic Tract ◽  
Average Latency ◽  
Stimulation Of

1. Stimulation of the sensorimotor cortex was found to excite and/or inhibit nociceptive spinothalamic tract cells. Thirteen wide dynamic range cells were inhibited by cortical stimulation, 6 were excited and 14 were both excited and inhibited. Four of six high-threshold cells were excited and one was inhibited. 2. Intermediate (200 ms) or long (2 s) duration conditioning trains were effective in reducing responses of spinothalamic cells evoked by noxious mechanical or thermal stimuli and by A- and C-fiber volleys in the sural nerve. Preferential inhibition of low-threshold responses with little or no effect on high-threshold discharges was observed in some cases. 3. Inhibitory actions were obtained primarily from stimulation of the SI sensory cortex and area 5, while excitation or excitation followed by inhibition was the dominant effect from motor cortex (area 4). Spinothalamic cells were also excited by stimulation of the medullary pyramid. 4. In eight animals extensive mapping of the sensorimotor cortex showed that for a given cell, stimulation of the sensory cortex produced inhibition while stimulation of motor cortex resulted in excitation. 5. The average latency of inhibition from sensory cortex was 29.8 +/- 10 ms, while the average latency of excitation from motor cortex was significantly shorter, 13.5 +/- 9 ms. The shortest latencies for excitation from pyramidal stimulation in the cases evaluated ranged from 2 to 9 ms. 6. Spinal cord lesions were made in five animals to determine the descending pathway(s) mediating corticofugal effects. Cortical and pyramidal effects were eliminated or considerably reduced by lesions involving the dorsal part of the lateral funiculus. This observation combined with latency data suggest that the corticospinal tract may be involved in the mediation of cortical excitation, while both pyramidal and extrapyramidal pathways are likely to be involved in cortical inhibition.

Applications of predictive control in neuroscience

2013 ◽  
Vol 36 (3) ◽  
pp. 208-208
Author(s):  
Bruce Bridgeman
Keyword(s):  
Motor Cortex ◽  
Predictive Control ◽  
Receptive Fields ◽  
Sensory Cortex ◽  
Visual World ◽  
Stimulus Properties ◽  
Unexpected Stimulus

AbstractThe sensory cortex has been interpreted as coding information rather than stimulus properties since Sokolov in 1960 showed increased response to an unexpected stimulus decrement. The motor cortex is also organized around expectation, coding the goal of an act rather than a set of muscle movements. Expectation drives not only immediate responses but also the very structure of the cortex, as demonstrated by development of receptive fields that mirror the structure of the visual world.

scholarly journals Trunk sensory and motor cortex is preferentially integrated with hindlimb sensory information that supports trunk stabilization

2020 ◽  
Author(s):  
Bharadwaj Nandakumar ◽  
Gary H. Blumenthal ◽  
Francois Philippe Pauzin ◽  
Karen A. Moxon
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Motor Cortex ◽  
Postural Control ◽  
Functional Recovery ◽  
Sensorimotor Integration ◽  
Cortical Reorganization ◽  
Sensory Cortex ◽  
Proprioceptive Information ◽  
Cord Injury

AbstractSensorimotor integration in the trunk system has been poorly studied despite its importance for examining functional recovery after neurological injury or disease. Here, we mapped the relationship between thoracic dorsal root ganglia and trunk sensory cortex (S1) to create a detailed map of the extent and internal organization of trunk primary sensory cortex, and trunk primary motor cortex (M1) and showed that both cortices are somatotopically complex structures that are larger than previously described. Surprisingly, projections from trunk S1 to trunk M1 were not anatomically organized. We found relatively weak sensorimotor integration between trunk M1 and S1 and between trunk M1 and forelimb S1 compared to extensive integration between trunk M1 and hindlimb S1 and M1. This strong trunk/hindlimb connection was identified for high intensity stimuli that activated proprioceptive pathways. To assess the implication of this integration, the responses in sensorimotor cortex were examined during a postural control task and supported sensorimotor integration between hindlimb sensory and lower trunk motor cortex. Together, these data suggest that trunk M1 is guided predominately by hindlimb proprioceptive information that reached the cortex directly via the thalamus. This unique sensorimotor integration suggests an essential role for the trunk system in postural control, and its consideration could be important for understanding studies regarding recovery of function after spinal cord injury.SignificanceThis work identifies extensive sensorimotor integration between trunk and hindlimb cortices, demonstrating that sensorimotor integration is an operational mode of the trunk cortex in intact animals. The functional role of this integration was demonstrated for postural control when the animal was subjected to lateral tilts. Furthermore, these results provide insight into cortical reorganization after spinal cord injury making clear that sensorimotor integration after SCI is an attempt to restore sensorimotor integration that existed in the intact system. These results could be used to tailor rehabilitative strategies to optimize sensorimotor integration for functional recovery.

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