# The neural basis of touch and proprioception in the primate orofacial sensorimotor cortex

> **NIH NIH R01** · UNIVERSITY OF CHICAGO · 2020 · $543,808

## Abstract

PROJECT SUMMARY
There is a fundamental gap in understanding the cortical representations and integration of tactile and proprio-
ceptive sensations accompanying bodily movements in general and oromotor behavior in particular. This repre-
sents an important problem because until it is understood, the mechanisms underlying orofacial pain, sensorimo-
tor impairments, and sensorimotor integration will remain largely incomprehensible. The goal of the proposed
research is to dissociate the cortical representations of touch and proprioception during natural feeding behavior
by using an innovative sequence of nerve blocks together with multi-electrode array recordings and 3D tracking
of tongue and jaw movements in non-human primates. The tongue is a unique structure for investigating this
because it is in constant motion and assumes various postures when touching other oral structures (e.g., teeth,
palate, and gingiva) during feeding. More importantly, the tactile and proprioceptive afferent fibers innervating
the tongue enter the central nervous system separately in trigeminal (lingual nerve branch) and hypoglossal
cranial nerves, respectively. Such unique anatomy enables experimental dissociation of touch and propriocep-
tion. The central hypothesis is that tongue posture and contact with other oral structures are reflected in the
proprioception- and tactile-related responses of neurons in the primary somatosensory (SIo) and primary motor
(MIo) areas of the orofacial sensorimotor cortex (OSMcx). This hypothesis will be tested by pursuing three spe-
cific aims: (1) determine how information about tongue posture and contact with other oral structures is encoded
in MIo and SIo during natural feeding by eliminating tactile stimuli to the tongue and surrounding oral structures
through sequential nerve blocks to the maxillary and mandibular sensory branches of the trigeminal nerve, (2)
dissociate the neurons’ motor response from a proprioceptive response by using intracortical microstimulation
(ICMS) to evoke muscle twitches while tactile inputs to the tongue and other oral structures are blocked, and (3)
characterize the functional connectivity between tactile- and proprioceptive-related regions in OSMcx by spectral
coherence analysis and by the effects of low-intensity ICMS of a tactile region on a proprioceptive one and vice
versa. The proposed research uses an innovative approach that leverages the unique sensory innervation of the
oral region by different cranial nerves and integrates the simultaneous neural recording and tracking of the
tongue and jaw movements in 3D. The proposed research is significant because it will bridge the results of
decades of research on cortical representation of oral somatosensation and on the biomechanics of tongue/jaw
movements during oromotor behavior, thus filling an important gap in the field. The knowledge gained from this
work will lay the groundwork for future studies on oral somatosensation, pain mechanisms, and se...

## Key facts

- **NIH application ID:** 9895722
- **Project number:** 5R01DE027236-03
- **Recipient organization:** UNIVERSITY OF CHICAGO
- **Principal Investigator:** Fritzie Isip Arce-McShane
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $543,808
- **Award type:** 5
- **Project period:** 2018-04-06 → 2023-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9895722

## Citation

> US National Institutes of Health, RePORTER application 9895722, The neural basis of touch and proprioception in the primate orofacial sensorimotor cortex (5R01DE027236-03). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9895722. Licensed CC0.

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