# Brainstem circuits controlling gastrointestinal function

> **NIH NIH R01** · PENNSYLVANIA STATE UNIV HERSHEY MED CTR · 2020 · $393,892

## Abstract

Project Summary/Abstract
 Autonomic dysfunctions, especially gastrointestinal motility disorders, occur frequently in parkinsonian
patients and are often prodromic to the clinical diagnosis of Parkinson’s disease (PD). Chronic constipation
and delayed gastric emptying are observed in many parkinsonian patients and are especially troublesome; the
latter provides an additional unresolved complication to the absorption and appropriate therapeutic dosing
regimen of L-DOPA, i.e. the main therapy used to treat PD-related motor dysfunctions.
 In the quest to elucidate the treatment of parkinsonian-related gastroparesis, it is necessary to
understand the factors, including the environmental influences, which contribute to the etiology and
development of idiopathic PD.
 Several epidemiological studies have associated an increased incidence of PD with pesticide or
herbicide exposure and rural location/lifestyle. Similarly, studies have indicated that vegetarians who follow a
diet high in plant seed lectins have a higher incidence of PD compared to non-vegetarians. Of note, some
vegetable cultivars in SE Asia have enriched lectin concentrations of up to 1%.
 Based on our preliminary studies that indicate impaired gastric motility upon administration of
subthreshold doses of lectins and the herbicide paraquat, we propose the following novel hypothesis: “lectin-
mediated retrograde transport of environmental toxins disrupts the brain-gut axis through a vagally-dependent
ENS-DMV-SNpc pathway” prior to the development of PD-related motor dysfunctions. To investigate this novel
hypothesis, we will use a combination of in vivo optogenetic, electrophysiological, anatomical and behavioral
approaches in rodents to investigate on the gastric-related neural pathways affected in parkinsonian-related
gastric dysfunctions.

## Key facts

- **NIH application ID:** 9959397
- **Project number:** 5R01DK055530-19
- **Recipient organization:** PENNSYLVANIA STATE UNIV HERSHEY MED CTR
- **Principal Investigator:** Kirsteen Nairn Browning
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $393,892
- **Award type:** 5
- **Project period:** 1998-09-05 → 2024-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9959397

## Citation

> US National Institutes of Health, RePORTER application 9959397, Brainstem circuits controlling gastrointestinal function (5R01DK055530-19). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/9959397. Licensed CC0.

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