Ano-rectal stimulation provides an important model for the processing of somatosensory and visceral sensations in the human nervous system. In spite of their anatomical proximity, the anal canal is innervated by somatosensory afferents whereas the rectum is innervated by the visceral nervous system. In a functional magnetic resonance (fMRI) experiment, we examined the cerebral responses to pneu...

Middle ear sensory information has never been localized in the homunculus of the somatosensory cortex (S1). We investigated the somatosensory representation of the middle ear in 15 normal hearing subjects. We applied small air pressure variations to the tympanic membrane while performing a 3T-fMRI study. Unilateral stimulations of the right ear triggered bilateral activations in the caudal part...

The detailed time courses of cortical activities and source localizations following passive finger movement were studied using whole-head magnetoencephalography (MEG). We recorded motor-related cortical magnetic fields following voluntary movement and somatosensory-evoked magnetic fields following passive movement (PM) in 13 volunteers. The most prominent movement-evoked magnetic field (MEF1) f...

The H-2Z1 transgene is restricted to a subset of layer IV neurons in the postnatal mouse cortex and delineates exactly the somatosensory area. Expression of the H-2Z1 transgene was used as an areal marker to determine when the parietal cortex becomes committed to a somatosensory identity. We have shown previously that grafts dissected from embryonic day 13.5 (E13.5) H-2Z1 cortex and transplante...

Somatosensory stimuli guide and shape behavior, from immediate protective reflexes to longer-term learning higher-order processes related pain touch. However, somatosensory inputs are challenging control in awake mammals due the diversity nature of contact stimuli. Application cutaneous is currently limited relatively imprecise methods as well subjective behavioral measures. The strategy we pre...

In the primary somatosensory cortex (SI) of non-human primates, receptive field properties have been shown to differ between its sub-areas with increasing convergence in areas 1 and 2 as compared with area 3b. In this study, we searched for a similar functional organization of human SI. We performed fMRI in healthy subjects during separate or simultaneous electrical stimulation of the second an...

MEG is a useful method to know brain activities, and has a remarkable feature that the source location is estimated with high accuracy. However MEG is insensitive to a radial current dipole, because a radial dipole in a sphere makes no magnetic field outside the sphere and the shape of human head resembles a sphere. To realize more accurate localization, there is a requirement to estimate a rad...

Moving stimuli activate all of the mechanoreceptive afferents involved in discriminative touch, but their signals covary with several parameters, including texture. Despite this, the brain extracts precise information about tactile speed, and humans can scale the tangential speed of moving surfaces as long as they have some surface texture. Speed estimates, however, vary with texture: lower est...

Table 1. Location and spatial distribution of individual vibrissa intrinsic map peaks. ML: lateral distance of map peak relative to the horizontal midline passing through bregma point. RC: caudal distance of map peak relative to bregma. s.d.: standard deviation of the spread of mapped eIOS centroids after affine transformation (cf. figure 4b). s.d.: standard deviation of the spread of mapped eI...