# Understanding multisensory hypersensitivity in chronic pain states

> **NIH NIH R37** · OREGON HEALTH & SCIENCE UNIVERSITY · 2020 · $379,746

## Abstract

PROJECT SUMMARY
 Many chronic pain patients complain of abnormal sensitivity to multiple sensory
modalities, including light, sound, and smell. The underlying neural basis remains a puzzle
and these claims are often viewed with suspicion, since sensory acuity per se is not
enhanced, nor is there amplified processing in primary sensory pathways. The central
thesis of this proposal is that dysfunction of brainstem pain-modulating systems, already
thought to contribute to pain in these conditions, is also likely to play a role in multisensory
hypersensitivity. This hypothesis is based on our unexpected observation that a subset of
pain-modulating neurons in the rostral ventromedial medulla, the final output of an important
brainstem pain-modulating system, respond to light. In three Specific Aims using single-cell
recording approaches in rat, we will fully characterize the RVM response to light, generating
stimulus-response functions and establishing the relevant spectrum. We will also determine
whether photoresponsiveness of these neurons is enhanced in an animal model of migraine
headache (where photosensitivity is well documented) or in a persistent inflammatory state.
Finally, we will investigate “top-down” modulation of photoresponsiveness from a higher
brain structure known to contribute to stress-induced hyperalgesia and implicated in
endocrine, autonomic, and behavioral responses to mild stress. The present proposal
brings together electrophysiological and behavioral approaches to determine how light
engages pain-modulating systems, effectively converting a visual stimulus to a somatic
sensation, producing discomfort and aversion. These studies will provide fundamental
insights into the neurobiological mechanisms of multisensory hypersensitivity, information
critical to developing more appropriate treatments for migraine and other chronic pain
disorders.

## Key facts

- **NIH application ID:** 9832211
- **Project number:** 5R37NS098660-04
- **Recipient organization:** OREGON HEALTH & SCIENCE UNIVERSITY
- **Principal Investigator:** Mary Magdalen Heinricher
- **Activity code:** R37 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $379,746
- **Award type:** 5
- **Project period:** 2017-01-15 → 2020-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9832211

## Citation

> US National Institutes of Health, RePORTER application 9832211, Understanding multisensory hypersensitivity in chronic pain states (5R37NS098660-04). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9832211. Licensed CC0.

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