Somatosensory Processing in the Human Inferior Prefrontal Cortex

2002 ◽  
Vol 88 (3) ◽  
pp. 1400-1406 ◽  
Author(s):  
Matthew C. Hagen ◽  
David H. Zald ◽  
Tricia A. Thornton ◽  
José V. Pardo
Keyword(s):  
Inferior Frontal Gyrus ◽  
Sensory Stimulation ◽  
Brain Regions ◽  
Somatosensory Processing ◽  
Somatosensory Stimulation ◽  
Tactile Stimuli ◽  
Somatosensory Cortices ◽  
Frontal Operculum ◽  
Frontal Activity ◽  
Ventral Area

Three inferior prefrontal regions in the monkey receive afferents from somatosensory cortices: the orbitofrontal cortex (OFC), the ventral area of the principal sulcus, and the anterior frontal operculum. To determine whether these areas show responses to tactile stimuli in humans, we examined data from an ongoing series of PET studies of somatosensory processing. Unlike previous work showing ventral frontal activity to hedonic (pleasant/unpleasant) sensory stimulation, the tactile stimuli used in these studies had a neutral hedonic valence. Our data provide evidence for at least two discrete ventral frontal brain regions responsive to somatosensory stimulation: 1) the posterior inferior frontal gyrus (IFG) and adjacent anterior frontal operculum, and 2) the OFC. The former region (posterior IFG/anterior frontal operculum) may have a more specific role in attending to tactile stimuli.

scholarly journals Peripheral sensory stimulation elicits global slow waves by recruiting somatosensory cortex bilaterally

2021 ◽  
Vol 118 (8) ◽  
pp. e2021252118
Author(s):  
Zachary P. Rosenthal ◽  
Ryan V. Raut ◽  
Ryan M. Bowen ◽  
Abraham Z. Snyder ◽  
Joseph P. Culver ◽  
...  
Keyword(s):  
Somatosensory Cortex ◽  
Neural Plasticity ◽  
Low Frequency ◽  
Sensory Stimulation ◽  
Slow Waves ◽  
Somatosensory Stimulation ◽  
State Dependent ◽  
Calcium Indicator ◽  
Somatosensory Cortices ◽  
Peripheral Sensory

Slow waves (SWs) are globally propagating, low-frequency (0.5- to 4-Hz) oscillations that are prominent during sleep and anesthesia. SWs are essential to neural plasticity and memory. However, much remains unknown about the mechanisms coordinating SW propagation at the macroscale. To assess SWs in the context of macroscale networks, we recorded cortical activity in awake and ketamine/xylazine-anesthetized mice using widefield optical imaging with fluorescent calcium indicator GCaMP6f. We demonstrate that unilateral somatosensory stimulation evokes bilateral waves that travel across the cortex with state-dependent trajectories. Under anesthesia, we observe that rhythmic stimuli elicit globally resonant, front-to-back propagating SWs. Finally, photothrombotic lesions of S1 show that somatosensory-evoked global SWs depend on bilateral recruitment of homotopic primary somatosensory cortices. Specifically, unilateral lesions of S1 disrupt somatosensory-evoked global SW initiation from either hemisphere, while spontaneous SWs are largely unchanged. These results show that evoked SWs may be triggered by bilateral activation of specific, homotopically connected cortical networks.

scholarly journals The ‘creatures’ of the human cortical somatosensory system

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Noam Saadon-Grosman ◽  
Yonatan Loewenstein ◽  
Shahar Arzy
Keyword(s):  
Somatosensory Cortex ◽  
Somatosensory System ◽  
Brain Regions ◽  
Human Cognition ◽  
Whole Body ◽  
Functional Specialization ◽  
Body Parts ◽  
Somatosensory Processing ◽  
Somatosensory Stimulation ◽  
Cortical Parcellation

Abstract Penfield’s description of the ‘homunculus’, a ‘grotesque creature’ with large lips and hands and small trunk and legs depicting the representation of body-parts within the primary somatosensory cortex (S1), is one of the most prominent contributions to the neurosciences. Since then, numerous studies have identified additional body-parts representations outside of S1. Nevertheless, it has been implicitly assumed that S1’s homunculus is representative of the entire somatosensory cortex. Therefore, the distribution of body-parts representations in other brain regions, the property that gave Penfield’s homunculus its famous ‘grotesque’ appearance, has been overlooked. We used whole-body somatosensory stimulation, functional MRI and a new cortical parcellation to quantify the organization of the cortical somatosensory representation. Our analysis showed first, an extensive somatosensory response over the cortex; and second, that the proportional representation of body parts differs substantially between major neuroanatomical regions and from S1, with, for instance, much larger trunk representation at higher brain regions, potentially in relation to the regions’ functional specialization. These results extend Penfield’s initial findings to the higher level of somatosensory processing and suggest a major role for somatosensation in human cognition.

A Cortical Network Sensitive to Stimulus Salience in a Neutral Behavioral Context Across Multiple Sensory Modalities

2002 ◽  
Vol 87 (1) ◽  
pp. 615-620 ◽  
Author(s):  
Jonathan Downar ◽  
Adrian P. Crawley ◽  
David J. Mikulis ◽  
Karen D. Davis
Keyword(s):  
Response Selection ◽  
Inferior Frontal Gyrus ◽  
Superior Temporal Gyrus ◽  
Brain Regions ◽  
Anterior Cingulate ◽  
Behavioral Context ◽  
General Role ◽  
Sensory Stimuli ◽  
Tactile Stimuli ◽  
Stimulus Salience

Stimulus salience depends both on behavioral context and on other factors such as novelty and frequency of occurrence. The temporo-parietal junction (TPJ) responds preferentially to behaviorally relevant stimuli and is thought to play a general role in detecting salient stimuli. If so, it should respond preferentially to novel or infrequent events, even in a neutral behavioral context. To test this hypothesis, we used event-related functional magnetic resonance imaging (fMRI) to identify brain regions sensitive to the novelty of visual, auditory, and tactile stimuli during passive observation. Cortical regions with a greater response to novel than familiar stimuli across all modalities were identified at two sites in the TPJ region: the supramarginal gyrus (SMG) and superior temporal gyrus. The right inferior frontal gyrus (IFG), right anterior insula, left anterior cingulate cortex (ACC), and left inferior temporal gyrus also showed sensitivity to novelty. The novelty-sensitive TPJ activation in SMG overlaps a region previously identified as sensitive behavioral context. This region may play a general role in identifying salient stimuli, whether the salience is due to the current behavioral context or not. The IFG activation overlaps regions previously identified as responsive to nonnovel sensory events regardless of behavioral context. The IFG may therefore play a general role in stimulus evaluation rather than a specific role in identifying novel stimuli. The ACC activation lies in a region active during complex response-selection tasks, suggesting a general role in detecting and/or planning responses to salient events. A frontal-parietal-cingulate network may serve to identify and evaluate salient sensory stimuli in general.

scholarly journals Brain Abnormalities in Individuals with a Desire for a Healthy Limb Amputation: Somatosensory, Motoric or Both? A Task-Based fMRI Verdict

2021 ◽  
Vol 11 (9) ◽  
pp. 1248
Author(s):  
Martina Gandola ◽  
Laura Zapparoli ◽  
Gianluca Saetta ◽  
Carlo Reverberi ◽  
Gerardo Salvato ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Resting State ◽  
Motor Task ◽  
Body Part ◽  
Brain Regions ◽  
Limb Amputation ◽  
Resting State Functional Connectivity ◽  
Somatosensory Stimulation ◽  
Somatosensory Cortices ◽  
The Right

Body integrity dysphoria (BID), a long-lasting desire for the amputation of physically healthy limbs, is associated with reduced fMRI resting-state functional connectivity of somatosensory cortices. Here, we used fMRI to evaluate whether these findings could be replicated and expanded using a task-based paradigm. We measured brain activations during somatosensory stimulation and motor tasks for each of the four limbs in ten individuals with a life-long desire for the amputation of the left leg and fourteen controls. For the left leg, BID individuals had reduced brain activation in the right superior parietal lobule for somatosensory stimulation and in the right paracentral lobule for the motor task, areas where we previously found reduced resting-state functional connectivity. In addition, for somatosensory stimulation only, we found a robust reduction in activation of somatosensory areas SII bilaterally, mostly regardless of the stimulated body part. Areas SII were regions of convergent activations for signals from all four limbs in controls to a significantly greater extent than in subjects with BID. We conclude that BID is associated with altered integration of somatosensory and, to a lesser extent, motor signals, involving limb-specific cortical maps and brain regions where the first integration of body-related signals is achieved through convergence.

scholarly journals The “creatures” of the human cortical somatosensory system

2019 ◽  
Author(s):  
N. Saadon-Grosman ◽  
Y. Loewenstein ◽  
S. Arzy
Keyword(s):  
Somatosensory Cortex ◽  
Somatosensory System ◽  
Brain Regions ◽  
Human Cognition ◽  
Whole Body ◽  
Functional Specialization ◽  
Body Parts ◽  
Somatosensory Processing ◽  
Somatosensory Stimulation ◽  
Cortical Parcellation

AbstractPenfield’s description of the “homunculus”, a “grotesque creature” with large lips and hands and small trunk and legs depicting the representation of body-parts within the primary somatosensory cortex (S1), is one of the most prominent contributions to the neurosciences. Since then, numerous studies have identified additional body-parts representations outside of S1. Nevertheless, it has been implicitly assumed that S1’s homunculus is representative of the entire somatosensory cortex. Therefore, the distribution of body-parts representations in other brain regions, the property that gave Penfield’s homunculus its famous “grotesque” appearance, has been overlooked. We used whole-body somatosensory stimulation, functional MRI and a new cortical parcellation to quantify the organization of the cortical somatosensory representation. Our analysis showed first, an extensive somatosensory response over the cortex; and second, that the proportional representation of body-parts differs substantially between major neuroanatomical regions and from S1, with, for instance, much larger trunk representation at higher brain regions, potentially in relation to the regions’ functional specialization. These results extend Penfield’s initial findings to the higher level of somatosensory processing and suggest a major role for somatosensation in human cognition.

scholarly journals Ipsilateral stimulus encoding in primary and secondary somatosensory cortex of awake mice

2021 ◽  
Author(s):  
Aurélie Pala ◽  
Garrett B Stanley
Keyword(s):  
Somatosensory Cortex ◽  
The Body ◽  
Mammalian Brain ◽  
Equal Proportion ◽  
Somatosensory Processing ◽  
Secondary Somatosensory Cortex ◽  
Tactile Stimuli ◽  
Somatosensory Cortices ◽  
Stimulus Responsive ◽  
Layer 4

Lateralization is a hallmark of somatosensory processing in the mammalian brain. However, in addition to their contralateral representation, unilateral tactile stimuli also modulate neuronal activity in somatosensory cortices of the ipsilateral hemisphere. The cellular organization and functional role of these ipsilateral stimulus responses in awake somatosensory cortices, especially regarding stimulus coding, are unknown. Here, we targeted silicon probe recordings to the vibrissa region of primary (S1) and secondary (S2) somatosensory cortex of awake head-fixed male and female mice while delivering ipsilateral and contralateral whisker stimuli. Ipsilateral stimuli drove larger and more reliable responses in S2 than in S1, and activated a larger fraction of stimulus-responsive neurons. Ipsilateral stimulus-responsive neurons were rare in layer 4 of S1, but were located in equal proportion across all layers in S2. Linear classifier analyses further revealed that decoding of the ipsilateral stimulus was more accurate in S2 than S1, while S1 decoded contralateral stimuli most accurately. These results reveal substantial encoding of ipsilateral stimuli in S1 and especially S2, consistent with the hypothesis that higher cortical areas may integrate tactile inputs across larger portions of space, spanning both sides of the body.

Forebrain organization representing baroreceptor gating of somatosensory afferents within the cortical autonomic network

2012 ◽  
Vol 108 (2) ◽  
pp. 453-466 ◽  
Author(s):  
Ruma Goswami ◽  
Maria Fernanda Frances ◽  
Craig Douglas Steinback ◽  
J. Kevin Shoemaker
Keyword(s):  
Lower Body Negative Pressure ◽  
Brain Activity ◽  
Muscle Sympathetic Nerve Activity ◽  
Cardiovascular Effects ◽  
Sensory Stimulation ◽  
Anterior Cingulate ◽  
Somatosensory Processing ◽  
Dorsal Anterior Cingulate Cortex ◽  
Burst Frequency ◽  
Somatosensory Stimulation

Somatosensory afferents are represented within the cortical autonomic network (CAN). However, the representation of somatosensory afferents, and the consequent cardiovascular effects, may be modified by levels of baroreceptor input. Thus, we examined the cortical regions involved with processing somatosensory inputs during baroreceptor unloading. Neuroimaging sessions (functional magnetic resonance imaging [fMRI]) recorded brain activity during 30 mmHg lower-body negative pressure (LBNP) alone and combined with somatosensory stimulation (LBNP+SS) of the forearm ( n = 14). Somatosensory processing was also assessed during increased sympathetic outflow via end-expiratory apnea. Heart rate (HR), blood pressure (BP), cardiac output (Q), and muscle sympathetic nerve activity (MSNA) were recorded during the same protocols in a separate laboratory session. SS alone had no effect on any cardiovascular or MSNA variable at rest. Measures of HR, BP, and Q during LBNP were not different compared with LBNP+SS. The rise in MSNA burst frequency was attenuated during LBNP+SS versus LBNP alone (8 vs. 12 bursts/min, respectively, P < 0.05). SS did not affect the change in MSNA during apnea. Activations within the insula and dorsal anterior cingulate cortex (ACC) observed during LBNP were not seen during LBNP+SS. Anterior insula and ACC activations occurring during apnea were not modified by SS. Thus, the absence of insular and dorsal ACC activity during LBNP+SS along with an attenuation of MSNA burst frequency suggest sympathoinhibitory effects of sensory stimulation during decreased baroreceptor input by a mechanism that includes conjoint insula-dorsal ACC regulation. These findings reveal that the level of baroreceptor input influences the forebrain organization of somatosensory afferents.

Somatosensory processing of non-painful tactile stimuli in patients with idiopathic trigeminal neuralgia

2006 ◽  
Vol 33 (S 1) ◽  
Author(s):  
E. Sarpaczki ◽  
M. Blatow ◽  
E. Nennig ◽  
A. Durst ◽  
D. Rasche ◽  
...  
Keyword(s):  
Trigeminal Neuralgia ◽  
Somatosensory Processing ◽  
Tactile Stimuli ◽  
Idiopathic Trigeminal Neuralgia

scholarly journals Brain networks underlying the processing of sound symbolism related to softness perception

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ryo Kitada ◽  
Jinhwan Kwon ◽  
Ryuichi Doizaki ◽  
Eri Nakagawa ◽  
Tsubasa Tanigawa ◽  
...  
Keyword(s):  
Inferior Frontal Gyrus ◽  
Sensory Modality ◽  
Brain Regions ◽  
Sound Symbolism ◽  
Matching Task ◽  
Unique Contribution ◽  
Superior Frontal Gyrus ◽  
Symbolic Information ◽  
Object Properties ◽  
Imaging Experiment

AbstractUnlike the assumption of modern linguistics, there is non-arbitrary association between sound and meaning in sound symbolic words. Neuroimaging studies have suggested the unique contribution of the superior temporal sulcus to the processing of sound symbolism. However, because these findings are limited to the mapping between sound symbolism and visually presented objects, the processing of sound symbolic information may also involve the sensory-modality dependent mechanisms. Here, we conducted a functional magnetic resonance imaging experiment to test whether the brain regions engaged in the tactile processing of object properties are also involved in mapping sound symbolic information with tactually perceived object properties. Thirty-two healthy subjects conducted a matching task in which they judged the congruency between softness perceived by touch and softness associated with sound symbolic words. Congruency effect was observed in the orbitofrontal cortex, inferior frontal gyrus, insula, medial superior frontal gyrus, cingulate gyrus, and cerebellum. This effect in the insula and medial superior frontal gyri was overlapped with softness-related activity that was separately measured in the same subjects in the tactile experiment. These results indicate that the insula and medial superior frontal gyrus play a role in processing sound symbolic information and relating it to the tactile softness information.

scholarly journals Diversity of neurovascular coupling dynamics along vascular arbors in layer II/III somatosensory cortex

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Ravi L. Rungta ◽  
Marc Zuend ◽  
Ali-Kemal Aydin ◽  
Éric Martineau ◽  
Davide Boido ◽  
...  
Keyword(s):  
Cerebral Cortex ◽  
Somatosensory Cortex ◽  
Cerebral Blood Volume ◽  
Transfer Functions ◽  
Neurovascular Coupling ◽  
Sensory Stimulation ◽  
Brain Regions ◽  
Blood Velocity ◽  
Functional Brain Imaging ◽  
Vascular Events

AbstractThe spatial-temporal sequence of cerebral blood flow (CBF), cerebral blood volume (CBV) and blood velocity changes triggered by neuronal activation is critical for understanding functional brain imaging. This sequence follows a stereotypic pattern of changes across different zones of the vasculature in the olfactory bulb, the first relay of olfaction. However, in the cerebral cortex, where most human brain mapping studies are performed, the timing of activity evoked vascular events remains controversial. Here we utilized a single whisker stimulation model to map out functional hyperemia along vascular arbours from layer II/III to the surface of primary somatosensory cortex, in anesthetized and awake Thy1-GCaMP6 mice. We demonstrate that sensory stimulation triggers an increase in blood velocity within the mid-capillary bed and a dilation of upstream large capillaries, and the penetrating and pial arterioles. We report that under physiological stimulation, response onset times are highly variable across compartments of different vascular arbours. Furthermore, generating transfer functions (TFs) between neuronal Ca2+ and vascular dynamics across different brain states demonstrates that anesthesia decelerates neurovascular coupling (NVC). This spatial-temporal pattern of vascular events demonstrates functional diversity not only between different brain regions but also at the level of different vascular arbours within supragranular layers of the cerebral cortex.

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