Diverse roles for the posteromedial thalamus in sensory evoked cortical plasticity

2020 ◽  
Author(s):  
Matthew James Buchan ◽  
Gemma Gothard ◽  
Alexander von Klemperer ◽  
Joram J van Rheede
Keyword(s):  
Somatosensory Cortex ◽  
Cortical Plasticity ◽  
Primary Somatosensory Cortex ◽  
Somatosensory Processing ◽  
Sensory Evoked

The posteromedial thalamus (POm) has extensive recurrent connectivity with the whisker-related primary somatosensory cortex (wS1) of rodents. However, its functional contribution to somatosensory processing in wS1 remains unclear. This article reviews several recent findings which begin to elucidate the role of POm in sensory evoked plasticity and discusses their implications for somatosensory processing.

Spatio-Temporal Subthreshold Receptive Fields in the Vibrissa Representation of Rat Primary Somatosensory Cortex

1998 ◽  
Vol 80 (6) ◽  
pp. 2882-2892 ◽  
Author(s):  
Christopher I. Moore ◽  
Sacha B. Nelson
Keyword(s):  
Receptive Field ◽  
Somatosensory Cortex ◽  
Rise Time ◽  
Cortical Plasticity ◽  
Temporal Dynamics ◽  
Receptive Fields ◽  
Excitatory Input ◽  
Primary Somatosensory Cortex ◽  
Spatio Temporal ◽  
Sensory Evoked

Moore, Christopher I. and Sacha B. Nelson. Spatio-temporal subthreshold receptive fields in the vibrissa representation of rat primary somatosensory cortex. J. Neurophysiol. 80: 2882–2892, 1998. Whole cell recordings of synaptic responses evoked by deflection of individual vibrissa were obtained from neurons within adult rat primary somatosensory cortex. To define the spatial and temporal properties of subthreshold receptive fields, the spread, amplitude, latency to onset, rise time to half peak amplitude, and the balance of excitation and inhibition of subthreshold input were quantified. The convergence of information onto single neurons was found to be extensive: inputs were consistently evoked by vibrissa one- and two-away from the vibrissa that evoked the largest response (the “primary vibrissa”). Latency to onset, rise time, and the incidence and strength of inhibitory postsynaptic potentials (IPSPs) varied as a function of position within the receptive field and the strength of evoked excitatory input. Nonprimary vibrissae evoked smaller amplitude subthreshold responses [primary vibrissa, 9.1 ± 0.84 (SE) mV, n = 14; 1-away, 5.1 ± 0.5 mV, n = 38; 2-away, 3.7 ± 0.59 mV, n = 22; 3-away, 1.3 ± 0.70 mV, n = 8] with longer latencies (primary vibrissa, 10.8 ± 0.80 ms; 1-away, 15.0 ± 1.2 ms; 2-away, 15.7 ± 2.0 ms). Rise times were significantly faster for inputs that could evoke action potential responses (suprathreshold, 4.1 ± 1.3 ms, n = 8; subthreshold, 12.4 ± 1.5 ms, n = 61). In a subset of cells, sensory evoked IPSPs were examined by deflecting vibrissa during injection of hyperpolarizing and depolarizing current. The strongest IPSPs were evoked by the primary vibrissa ( n = 5/5), but smaller IPSPs also were evoked by nonprimary vibrissae ( n = 8/13). Inhibition peaked by 10–20 ms after the onset of the fastest excitatory input to the cortex. This pattern of inhibitory activity led to a functional reversal of the center of the receptive field and to suppression of later-arriving and slower-rising nonprimary inputs. Together, these data demonstrate that subthreshold receptive fields are on average large, and the spatio-temporal dynamics of these receptive fields vary as a function of position within the receptive field and strength of excitatory input. These findings constrain models of suprathreshold receptive field generation, multivibrissa interactions, and cortical plasticity.

scholarly journals Dispositional empathy predicts primary somatosensory cortex activity while receiving touch by a hand

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Michael Schaefer ◽  
Anja Kühnel ◽  
Franziska Rumpel ◽  
Matti Gärtner
Keyword(s):  
Somatosensory Cortex ◽  
Anterior Cingulate ◽  
Primary Somatosensory Cortex ◽  
Rubber Hand ◽  
Somatosensory Cortices ◽  
Touch Perception ◽  
Trait Empathy ◽  
Human Perceptions ◽  
Dispositional Empathy

AbstractPrevious research revealed an active network of brain areas such as insula and anterior cingulate cortex when witnessing somebody else in pain and feeling empathy. But numerous studies also suggested a role of the somatosensory cortices for state and trait empathy. While recent studies highlight the role of the observer’s primary somatosensory cortex when seeing painful or nonpainful touch, the interaction of somatosensory cortex activity with empathy when receiving touch on the own body is unknown. The current study examines the relationship of touch related somatosensory cortex activity with dispositional empathy by employing an fMRI approach. Participants were touched on the palm of the hand either by the hand of an experimenter or by a rubber hand. We found that the BOLD responses in the primary somatosensory cortex were associated with empathy personality traits personal distress and perspective taking. This relationship was observed when participants were touched both with the experimenter’s real hand or a rubber hand. What is the reason for this link between touch perception and trait empathy? We argue that more empathic individuals may express stronger attention both to other’s human perceptions as well as to the own sensations. In this way, higher dispositional empathy levels might enhance tactile processing by top-down processes. We discuss possible implications of these findings.

Role of adenosine in regulation of regional cerebral blood flow in sensory cortex

1990 ◽  
Vol 259 (6) ◽  
pp. H1703-H1708 ◽  
Author(s):  
K. R. Ko ◽  
A. C. Ngai ◽  
H. R. Winn
Keyword(s):  
Somatosensory Cortex ◽  
Neuronal Response ◽  
Cortical Activation ◽  
Cranial Window ◽  
Adenosine Uptake ◽  
Pial Arterioles ◽  
Sciatic Nerve Stimulation ◽  
Sensory Evoked ◽  
Arteriolar Vasodilation

We have previously demonstrated that rat pial arterioles located on the somatosensory cortex dilated in response to contralateral sciatic nerve stimulation (SNS). We hypothesized that the vasodilation was mediated by adenosine, released as a result of somatosensory cortex activation. To test this hypothesis, we examined the effects of SNS (0.15-0.2 V, 5 ms, 5 Hz for 20 s) on pial arterioles under conditions of altered adenosine availability. Cerebrospinal fluid (CSF) adenosine was altered by perfusing mock CSF, under a cranial window in anesthetized rats, containing either an adenosine uptake competitor (dipyridamole or inosine) or an adenosine receptor blocker (theophylline). With CSF only, SNS caused pial arterioles (resting diam, 29 +/- 1 micron) to dilate by 38 +/- 10% (peak magnitude) for 32 +/- 2 s. Dipyridamole (10(-6) M) significantly (P less than 0.02) enhanced both the magnitude (to 62 +/- 12%) and duration (to 68 +/- 10 s) of the response. Similarly, inosine (10(-3) M) significantly (P less than 0.02) potentiated the vasodilative response from resting values of 27 +/- 5% and 34.8 +/- 4.1 s to 37 +/- 6% and 89.6 +/- 14.1 s. In contrast, theophylline (5 x 10(-5) M) significantly (P less than 0.001) attenuated arteriolar vasodilation from resting values of 38 +/- 5% and 29.3 +/- 1.2 s to 18 +/- 3% and 22.0 +/- 0.9 s. Neither dipyridamole nor theophylline had a significant effect on neuronal response (sensory-evoked response) recorded from the somatosensory cortex. These results suggest that adenosine is involved in the regulation of pial vasodilation during cerebral cortical activation.

Role of Primary Somatosensory Cortex in Active and Passive Touch

1996 ◽  
pp. 329-347 ◽  
Author(s):  
C. Elaine Chapman ◽  
François Tremblay ◽  
Stacey A. Ageranioti-Bélanger
Keyword(s):  
Somatosensory Cortex ◽  
Primary Somatosensory Cortex ◽  
Passive Touch

scholarly journals Computational Role of Large Receptive Fields in the Primary Somatosensory Cortex

2008 ◽  
Vol 100 (1) ◽  
pp. 268-280 ◽  
Author(s):  
Guglielmo Foffani ◽  
John K. Chapin ◽  
Karen A. Moxon
Keyword(s):  
Somatosensory Cortex ◽  
Receptive Fields ◽  
Spike Timing ◽  
Spike Count ◽  
Primary Somatosensory Cortex ◽  
Single Neurons ◽  
Tuning Curves ◽  
Tactile Stimuli ◽  
Somatosensory Information

Computational studies are challenging the intuitive view that neurons with broad tuning curves are necessarily less discriminative than neurons with sharp tuning curves. In the context of somatosensory processing, broad tuning curves are equivalent to large receptive fields. To clarify the computational role of large receptive fields for cortical processing of somatosensory information, we recorded ensembles of single neurons from the infragranular forelimb/forepaw region of the rat primary somatosensory cortex while tactile stimuli were separately delivered to different locations on the forelimbs/forepaws under light anesthesia. We specifically adopted the perspective of individual columns/segregates receiving inputs from multiple body location. Using single-trial analyses of many single-neuron responses, we obtained two main results. 1) The responses of even small populations of neurons recorded from within the same estimated column/segregate can be used to discriminate between stimuli delivered to different surround locations in the excitatory receptive fields. 2) The temporal precision of surround responses is sufficiently high for spike timing to add information over spike count in the discrimination between surround locations. This surround spike-timing code (i) is particularly informative when spike count is ambiguous, e.g., in the discrimination between close locations or when receptive fields are large, (ii) becomes progressively more informative as the number of neurons increases, (iii) is a first-spike code, and (iv) is not limited by the assumption that the time of stimulus onset is known. These results suggest that even though large receptive fields result in a loss of spatial selectivity of single neurons, they can provide as a counterpart a sophisticated temporal code based on latency differences in large populations of neurons without necessarily sacrificing basic information about stimulus location.

scholarly journals Understanding the role of the primary somatosensory cortex: Opportunities for rehabilitation

2015 ◽  
Vol 79 ◽  
pp. 246-255 ◽  
Author(s):  
M.R. Borich ◽  
S.M. Brodie ◽  
W.A. Gray ◽  
S. Ionta ◽  
L.A. Boyd
Keyword(s):  
Somatosensory Cortex ◽  
Primary Somatosensory Cortex

scholarly journals Distinct patterns of activity in individual cortical neurons and local networks in primary somatosensory cortex of mice evoked by mechanical limb stimulation

2020 ◽  
Author(s):  
Mischa V. Bandet ◽  
Bin Dong ◽  
Ian R. Winship
Keyword(s):  
Somatosensory Cortex ◽  
Cortical Neurons ◽  
Optical Recording ◽  
Primary Somatosensory Cortex ◽  
Autofluorescence Imaging ◽  
Neuronal Activation ◽  
Local Networks ◽  
Two Photon ◽  
Evoked Activity ◽  
Sensory Evoked

AbstractTo distinguish between somatic stimuli, the primary somatosensory cortex should process dissimilar stimuli with distinct patterns of neuronal activation. Two-photon calcium imaging permits simultaneous optical recording of sensory evoked activity in hundreds of cortical neurons during varied sensory stimulation. Hence, it allows a visualization of patterns of activity in individual neurons and local cortical networks in response to distinct stimulation. Here, flavoprotein autofluorescence imaging was used to map the somatosensory cortex of anaesthetized C57BL/6 mice, and in vivo two-photon Ca2+ imaging was used to define patterns of neuronal activation during mechanical stimulation of the contralateral forelimb or hindlimb at various frequencies (3, 10, 100, 200, and 300 Hz). The data revealed that neurons within the limb associated somatosensory cortex exhibit stimulus-specific patterns of activity. Subsets of neurons were found to have sensory-evoked activity that is either primarily responsive to single stimulus frequencies or broadly responsive to multiple frequencies of limb movement. High frequency stimuli were shown to elicit more activation across the population, with a greater percentage of the population responding and greater percentage of cells with high amplitude responses. Stimulus-evoked cell-cell correlations within these neuronal networks varied as a function of frequency of stimulation, such that each stimulus elicited a distinct pattern that was more consistent across multiple trials of the same stimulus compared to trials at different frequencies of stimulation. The variation in cortical response to these artificial stimuli can thus be represented by the population pattern of supra-threshold Ca2+ transients, the magnitude and temporal properties of the evoked activity, and the structure of the stimulus-evoked correlation between responsive neurons.

scholarly journals Human primary somatosensory cortex is differentially involved in vibrotaction and nociception

2017 ◽  
Vol 118 (1) ◽  
pp. 317-330 ◽  
Author(s):  
Cédric Lenoir ◽  
Gan Huang ◽  
Yves Vandermeeren ◽  
Samar Marie Hatem ◽  
André Mouraux
Keyword(s):  
Somatosensory Cortex ◽  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Primary Somatosensory Cortex ◽  
High Definition ◽  
Somatosensory Input ◽  
Differential Involvement ◽  
Somatosensory Stimuli ◽  
Stimulation Of

The role of the primary somatosensory cortex (S1) in vibrotaction is well established. In contrast, its involvement in nociception is still debated. Here we test whether S1 is similarly involved in the processing of nonnociceptive and nociceptive somatosensory input in humans by comparing the aftereffects of high-definition transcranial direct current stimulation (HD-tDCS) of S1 on the event-related potentials (ERPs) elicited by nonnociceptive and nociceptive somatosensory stimuli delivered to the ipsilateral and contralateral hands. Cathodal HD-tDCS significantly affected the responses to nonnociceptive somatosensory stimuli delivered to the contralateral hand: both early-latency ERPs from within S1 (N20 wave elicited by transcutaneous electrical stimulation of median nerve) and late-latency ERPs elicited outside S1 (N120 wave elicited by short-lasting mechanical vibrations delivered to index fingertip, thought to originate from bilateral operculo-insular and cingulate cortices). These results support the notion that S1 constitutes an obligatory relay for the cortical processing of nonnociceptive tactile input originating from the contralateral hemibody. Contrasting with this asymmetric effect of HD-tDCS on the responses to nonnociceptive somatosensory input, HD-tDCS over the sensorimotor cortex led to a bilateral and symmetric reduction of the magnitude of the N240 wave of nociceptive laser-evoked potentials elicited by stimulation of the hand dorsum. Taken together, our results demonstrate in humans a differential involvement of S1 in vibrotaction and nociception. NEW & NOTEWORTHY Whereas the role of the primary somatosensory cortex (S1) in vibrotaction is well established, its involvement in nociception remains strongly debated. By assessing, in healthy volunteers, the effect of high-definition transcranial direct current stimulation over S1, we demonstrate a differential involvement of S1 in vibrotaction and nociception.

Role of Primary Somatosensory Cortex in Perceptual Touch Detection and Discrimination

2020 ◽  
pp. 261-278
Author(s):  
R. Romo ◽  
A. Hernández ◽  
V. de Lafuente ◽  
A. Zainos ◽  
L. Lemus ◽  
...  
Keyword(s):  
Somatosensory Cortex ◽  
Primary Somatosensory Cortex

Role of Primary Somatosensory Cortex in Perceptual Touch Detection and Discrimination

2008 ◽  
pp. 215-232
Author(s):  
R. Romo ◽  
A. Hernández ◽  
V. de Lafuente ◽  
A. Zainos ◽  
L. Lemus ◽  
...  
Keyword(s):  
Somatosensory Cortex ◽  
Primary Somatosensory Cortex
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