Spinal signaling of C-fiber mediated pleasant touch in humans

Mapping Intimacies ◽

10.1101/780635 ◽

2019 ◽

Author(s):

Andrew G. Marshall ◽

Manohar L Sharma ◽

Kate Marley ◽

Hakan Olausson ◽

Francis P. McGlone

Keyword(s):

Tactile Stimulation ◽

The Body ◽

Lamina I ◽

Touch Perception ◽

C Fiber

AbstractC-tactile afferents form a distinct channel that encodes pleasant tactile stimulation. Prevailing views indicate they project, as with other unmyelinated afferents, in lamina I-spinothalamic pathways. However, we found that spinothalamic ablation in humans, whilst profoundly impairing pain, temperature and itch, had no effect on pleasant touch perception. Only discriminative touch deficits were seen. These findings preclude privileged C-tactile-lamina I-spinothalamic projections and imply integrated hedonic and discriminative spinal processing from the body.

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Spinal signalling of C-fiber mediated pleasant touch in humans

eLife ◽

10.7554/elife.51642 ◽

2019 ◽

Vol 8 ◽

Cited By ~ 13

Author(s):

Andrew G Marshall ◽

Manohar L Sharma ◽

Kate Marley ◽

Hakan Olausson ◽

Francis P McGlone

Keyword(s):

Tactile Stimulation ◽

The Body ◽

Lamina I ◽

Touch Perception ◽

C Fiber

C-tactile afferents form a distinct channel that encodes pleasant tactile stimulation. Prevailing views indicate they project, as with other unmyelinated afferents, in lamina I-spinothalamic pathways. However, we found that spinothalamic ablation in humans, whilst profoundly impairing pain, temperature and itch, had no effect on pleasant touch perception. Only discriminative touch deficits were seen. These findings preclude privileged C-tactile-lamina I-spinothalamic projections and imply integrated hedonic and discriminative spinal processing from the body.

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In your eyes: vision of the body alters touch perception in women with eating disorder symptoms

Psychological Research ◽

10.1007/s00426-021-01478-6 ◽

2021 ◽

Author(s):

Sofia Sacchetti ◽

Valentina Cazzato ◽

Francis McGlone ◽

Laura Mirams

Keyword(s):

Eating Disorder ◽

Tactile Stimulation ◽

Light Flash ◽

The Body ◽

Eating Disorder Symptoms ◽

Touch Perception ◽

Somatic Signal ◽

Study Participants ◽

Somatic Signal Detection Task ◽

Different Levels

AbstractWe investigated the effects of non-informative vision of the body on exteroceptive multisensory integration and touch perception in participants presenting with different levels of eating disorder (ED) symptoms. The study employed a sample of women reporting low (low ED; n = 31) vs high (high ED; n = 34) levels of subclinical ED symptoms who undertook the Somatic Signal Detection task (SSDT). During the SSDT, participants are required to detect near-threshold tactile stimulation at their fingertip with and without a simultaneous light flash next to the stimulated fingertip. Previous research has found that participants have a tendency to erroneously report touch sensations in the absence of the stimulation, and especially when the light flash is presented. In this study, participants completed the SSDT under two conditions: while their hand was visible (non-informative vision), and while their hand was hidden from sight (no vision). Non-informative vision of the hand was found to have a different effect on SSDT performances according to participants’ levels of ED symptoms. High ED participants were better able to correctly detect the touch during the SSDT when their hand was visible. Conversely, for low ED participants, vision of the body was linked to a greater effect of the light in inducing false reports of touch. We suggest that in those with high ED symptoms, vision of the body may exacerbate a predisposition to focusing on external rather than internal bodily information.

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The locust jump. I. The motor programme

Journal of Experimental Biology ◽

10.1242/jeb.66.1.203 ◽

1977 ◽

Vol 66 (1) ◽

pp. 203-219

Author(s):

W. J. Heitler ◽

M. Burrows

Keyword(s):

High Frequency ◽

Tactile Stimulation ◽

The Body ◽

Flexor Muscle ◽

Tactile Stimuli ◽

Extensor Muscles ◽

Trigger Activity ◽

Three Stages ◽

Motor Programme ◽

Made In

A motor programme is described for defensive kicking in the locust which is also probably the programme for jumping. The method of analysis has been to make intracellular recordings from the somata of identified motornuerones which control the metathoracic tibiae while defensive kicks are made in response to tactile stimuli. Three stages are recognized in the programme. (1) Initial flexion of the tibiae results from the low spike threshold of tibial flexor motorneurones to tactile stimulation of the body. (2) Co-contraction of flexor and extensor muscles followa in which flexor and extensor excitor motoneurones spike at high frequency for 300-600 ms. the tibia flexed while the extensor muscle develops tension isometrically to the level required for a kick or jump. (3) Trigger activity terminates the co-contraction by inhibiting the flexor excitor motorneurones and simultaneously exciting the flexor inhibitors. This causes relaxation of the flexor muscle and allows the tibiae to extend. If the trigger activity does not occur, the jump or kick is aborted, and the tibiae remain flexed.

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Ascending pathways in the spinal cord involved in the activation of subnucleus reticularis dorsalis neurons in the medulla of the rat

Journal of Neurophysiology ◽

10.1152/jn.1990.63.3.424 ◽

1990 ◽

Vol 63 (3) ◽

pp. 424-438 ◽

Cited By ~ 32

Author(s):

Z. Bing ◽

L. Villanueva ◽

D. Le Bars

Keyword(s):

Spinal Cord ◽

Electrical Stimulation ◽

The Body ◽

Cervical Cord ◽

Lateral Part ◽

Neuronal Responses ◽

C Fiber ◽

Dorsal Columns ◽

Dorsolateral Funiculus ◽

The Right

1. Recordings were made from neurons in the left medullary subnucleus reticularis dorsalis (SRD) of anesthetized rats. Two populations of neurons were recorded: neurons with total nociceptive convergence (TNC), which gave responses to A delta- and C-fiber activation from the entire body after percutaneous electrical stimulation, and neurons with partial nociceptive convergence (PNC), which responded to identical stimuli with an A delta-peak regardless of which part of the body was stimulated and with a C-fiber peak of activation from some, mainly contralateral, parts of the body. 2. The effects of various, acute, transverse sections of the cervical (C4-C5) spinal cord on the A delta- and C-fiber-evoked responses were investigated by building poststimulus histograms (PSHs) after 50 trials of supramaximal percutaneous electrical stimulation of the extremity of either hindpaw (2-ms duration; 3 times threshold for C-fiber responses), before and 30-40 min after making the spinal lesion. 3. In the case of TNC neurons, hemisections of the left cervical cord blocked the responses elicited from the right hindpaw and slightly, but not significantly, diminished those evoked from the left hindpaw. Conversely, hemisections of the right cervical cord abolished TNC responses elicited from the left hindpaw without significantly affecting the responses elicited from the right hindpaw. 4. Lesioning the dorsal columns or the left dorsolateral funiculus was found not to affect the TNC neuronal responses elicited from either hindpaw. By contrast, lesioning the left lateral funiculus or the most lateral part of the ventrolateral funiculus, respectively, reduced and blocked the responses elicited from the right hindpaw without affecting those evoked from the left hindpaw. 5. After lesions that included the most lateral parts of the left ventral funiculus, PNC neuronal responses elicited from the right hindpaw were also abolished, whereas those elicited from the left hindpaw remained unchanged. 6. We conclude that the signals responsible for the activation of SRD neurons travel principally in the lateral parts of the ventrolateral quadrant, a region that classically has been implicated in the transmission of noxious information. Both a crossed and a double-crossed pathway are involved in this process. The postsynaptic fibers of the dorsal columns and the spinocervical and spinomesencephalic tracts do not appear to convey signals that activate SRD neurons. 7. The findings also suggest that lamina I nociceptive specific neurons, the axons of which travel within the dorsolateral funiculus, do not contribute very much to the activation of SRD neurons.

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Embodied precision: Intranasal oxytocin modulates multisensory integration

10.1101/361261 ◽

2018 ◽

Author(s):

Laura Crucianelli ◽

Yannis Paloyelis ◽

Lucia Ricciardi ◽

Paul M Jenkinson ◽

Aikaterini Fotopoulou

Keyword(s):

Multisensory Integration ◽

Tactile Stimulation ◽

Estimation Error ◽

The Body ◽

Multisensory Perception ◽

Subjective Feeling ◽

Rubber Hand ◽

Perceptual Inference ◽

Double Blind ◽

Multisensory Input

AbstractMultisensory integration processes are fundamental to our sense of self as embodied beings. Bodily illusions, such as the rubber hand illusion (RHI) and the size-weight illusion (SWI), allow us to investigate how the brain resolves conflicting multisensory evidence during perceptual inference in relation to different facets of body representation. In the RHI, synchronous tactile stimulation of a participant’s hidden hand and a visible rubber hand creates illusory bodily ownership; in the SWI, the perceived size of the body can modulate the estimated weight of external objects. According to Bayesian models, such illusions arise as an attempt to explain the causes of multisensory perception and may reflect the attenuation of somatosensory precision, which is required to resolve perceptual hypotheses about conflicting multisensory input. Recent hypotheses propose that the precision or salience of sensorimotor representations is determined by modulators of synaptic gain, like dopamine, acetylcholine and oxytocin. However, these neuromodulatory hypotheses have not been tested in the context of embodied multisensory integration. The present, double-blind, placebo-controlled, crossed-over study (N = 41 healthy volunteers) aimed to investigate the effect of intranasal oxytocin (IN-OT) on multisensory integration processes, tested by means of the RHI and the SWI. Results showed that IN-OT enhanced the subjective feeling of ownership in the RHI, only when synchronous tactile stimulation was involved. Furthermore, IN-OT increased the embodied version of the SWI (quantified as weight estimation error). These findings suggest that oxytocin might modulate processes of visuo-tactile multisensory integration by increasing the precision of top-down signals against bottom-up sensory input.

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Distinct mechanisms of signal processing by lamina I spino-parabrachial neurons

Scientific Reports ◽

10.1038/s41598-019-55462-7 ◽

2019 ◽

Vol 9 (1) ◽

Author(s):

K. Agashkov ◽

V. Krotov ◽

M. Krasniakova ◽

D. Shevchuk ◽

Y. Andrianov ◽

...

Keyword(s):

Signal Processing ◽

Ex Vivo ◽

Network Activity ◽

Local Network ◽

Cellular Mechanisms ◽

Afferent Stimulation ◽

Lamina I ◽

C Fiber ◽

Nociceptive Input ◽

High Output

AbstractLamina I spino-parabrachial neurons (SPNs) receive peripheral nociceptive input, process it and transmit to the supraspinal centres. Although responses of SPNs to cutaneous receptive field stimulations have been intensively studied, the mechanisms of signal processing in these neurons are poorly understood. Therefore, we used an ex-vivo spinal cord preparation to examine synaptic and cellular mechanisms determining specific input-output characteristics of the neurons. The vast majority of the SPNs received a few direct nociceptive C-fiber inputs and generated one spike in response to saturating afferent stimulation, thus functioning as simple transducers of painful stimulus. However, 69% of afferent stimulation-induced action potentials in the entire SPN population originated from a small fraction (19%) of high-output neurons. These neurons received a larger number of direct Aδ- and C-fiber inputs, generated intrinsic bursts and efficiently integrated a local network activity via NMDA-receptor-dependent mechanisms. The high-output SPNs amplified and integrated the nociceptive input gradually encoding its intensity into the number of generated spikes. Thus, different mechanisms of signal processing allow lamina I SPNs to play distinct roles in nociception.

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Non-informative vision improves spatial tactile discrimination on the shoulder but does not influence detection sensitivity

Experimental Brain Research ◽

10.1007/s00221-020-05944-2 ◽

2020 ◽

Vol 238 (12) ◽

pp. 2865-2875

Author(s):

Fabrizio Leo ◽

Sara Nataletti ◽

Luca Brayda

Keyword(s):

Tactile Stimulation ◽

Detection Threshold ◽

Receptive Fields ◽

Judgment Task ◽

The Body ◽

Detection Sensitivity ◽

Body Parts ◽

Tactile Acuity ◽

Tactile Stimuli ◽

Numerosity Judgment

Abstract Vision of the body has been reported to improve tactile acuity even when vision is not informative about the actual tactile stimulation. However, it is currently unclear whether this effect is limited to body parts such as hand, forearm or foot that can be normally viewed, or it also generalizes to body locations, such as the shoulder, that are rarely before our own eyes. In this study, subjects consecutively performed a detection threshold task and a numerosity judgment task of tactile stimuli on the shoulder. Meanwhile, they watched either a real-time video showing their shoulder or simply a fixation cross as control condition. We show that non-informative vision improves tactile numerosity judgment which might involve tactile acuity, but not tactile sensitivity. Furthermore, the improvement in tactile accuracy modulated by vision seems to be due to an enhanced ability in discriminating the number of adjacent active electrodes. These results are consistent with the view that bimodal visuotactile neurons sharp tactile receptive fields in an early somatosensory map, probably via top-down modulation of lateral inhibition.

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Afferent projections to the lateral cervical nucleus: a microelectrode study

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1963.204.4.667 ◽

1963 ◽

Vol 204 (4) ◽

pp. 667-672 ◽

Cited By ~ 36

Author(s):

F. Morin ◽

S. T. Kitai ◽

H. Portnoy ◽

C. Demirjian

Keyword(s):

Tactile Stimulation ◽

The Body ◽

Joint Movement ◽

Single Neurons ◽

Small Areas ◽

Afferent Projections ◽

Lateral Cervical Nucleus ◽

Degree Of Convergence ◽

High Degree ◽

Stimulation Of

The lateral cervical nucleus was explored with microelectrodes in lightly anesthetized cats. Extracellular responses were recorded from 160 neurons following physiological stimulation of the ipsilateral side of the body from the neck to the tail. The stimuli activating the neurons were touch, pressure, and joint movement. Neurons responding to touch were more prevalent than neurons responding to pressure on the skin or on deep structures; those responding to joint movements were a small fraction of the neuronal sample studied. For the three stimuli tested, the limbs were more prominently represented than the trunk. Tactile and pressure peripheral fields activating single neurons were of three types: restricted (a few hairs, small areas within one segment of a limb), large (wide areas of the trunk, whole limb), and very large (whole ipsilateral aspect of the body, both limbs). Restricted fields were less numerous than the large fields. One-third of the fields activating single neurons following tactile stimulation was of the very large type. The existence of the very large fields indicated a high degree of convergence of afferents onto neurons of the cervical nucleus.

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Lateral Asymmetry and Tactile Sensitivity

Perceptual and Motor Skills ◽

10.2466/pms.1988.67.1.55 ◽

1988 ◽

Vol 67 (1) ◽

pp. 55-62 ◽

Cited By ~ 14

Author(s):

Karen L. Kaplan-Solms ◽

Michael M. Saling

Keyword(s):

Tactile Stimulation ◽

The Body ◽

Lateral Distribution ◽

Tactile Sensitivity ◽

Review Of The Literature ◽

Lateral Asymmetry ◽

Leftward Bias ◽

Experimental Support ◽

Female Breast ◽

The Right

Weinstein found in 1963 that the left female breast is more sensitive to tactile stimulation than the right breast. Saling and Cooke in 1984 hypothesized that this asymmetry in breast sensitivity underlies the well-documented leftward bias in maternal cradling behaviour, which is independent of manual specialization. Our interest in the Saling and Cooke hypothesis led to an attempt to replicate Weinstein's 1963 study. His findings were not supported. Further, a review of the literature on the lateral distribution of cutaneous thresholds showed that there is little experimental support for the widely held belief that the left side of the body is uniformly more sensitive than the right.

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