# Itch-specific brain circuit and dopaminergic gene polymorphisms influencing individual differences in itch perception

> **NIH NIH R01** · UNIVERSITY OF MIAMI SCHOOL OF MEDICINE · 2024 · $346,162

## Abstract

Abstract
Itch is a global health problem, affecting tens of millions of people. The brain plays a crucial role in itch
perception; thus the specific circuit for itch processing in the brain has the potential to become a therapeutic
target for itch in a wide range of pruritic diseases. Our understanding about the brain mechanism of itch has
advanced in the past decades. Previous studies identified a key brain circuit related to itch, which includes the
ascending pathway projecting from the thalamus to the posterior insular cortex (pIC) and networks originating
from the pIC. In addition, dopamine was found to be a key neurotransmitter associated with itch. These
achievements have also identified two important topics that must be understood to develop effective itch
treatment targeting the brain. First, the brain circuit of itch is similar to that of pain, though itch and pain are
clearly distinct sensations. An itch-specific ascending pathway and network have not yet been identified within
the circuit (an itch-specific circuit). Second, there could be dopaminergic gene polymorphisms that determine
individual differences in itch perception. If such polymorphisms are identified, brain imaging studies focusing on
these genes can identify key loci regulating itch perception within the itch-specific circuit. This line of work will
eventually enable us to develop brain-based, tailored itch treatment. To this end, it is crucial to identify an itch-
specific circuit and dopaminergic gene polymorphisms influencing individual differences in itch perception. Our
research proposal will address this significant gap. Aims 1 and 2 will use fMRI to determine an itch-specific
ascending pathway and network by comparing brain activity between itch and pain stimuli. Aim 3 will use our
novel method for quantitatively assessing genetic impacts on itch to identify dopaminergic gene polymorphisms
that influence individual differences in itch perception. Success of our project will eventually lead to the
development of brain-based tailored itch treatment, which will advance the treatment of chronic itch regardless
of the underlying etiology.

## Key facts

- **NIH application ID:** 10913583
- **Project number:** 5R01NS126198-02
- **Recipient organization:** UNIVERSITY OF MIAMI SCHOOL OF MEDICINE
- **Principal Investigator:** Hideki Mochizuki
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $346,162
- **Award type:** 5
- **Project period:** 2023-09-01 → 2028-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10913583

## Citation

> US National Institutes of Health, RePORTER application 10913583, Itch-specific brain circuit and dopaminergic gene polymorphisms influencing individual differences in itch perception (5R01NS126198-02). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10913583. Licensed CC0.

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