# Neural Circuits Controlling Lacrimation

> **NIH NIH R01** · WASHINGTON UNIVERSITY · 2024 · $464,776

## Abstract

PROJECT SUMMARY
 Tear secretion (lacrimation) is an essential mechanism that lubricates our eyes and helps reduce eye
irritants and microbial infections. Lacrimal deficiency is associated with many systemic or ocular diseases
including primary Sjögren's syndrome, lupus, dry eyes, congenital alacrima, and viral infections. Previous studies
have suggested that the superior salivatory nucleus (SSN) controls lacrimation. However, direct molecular and
genetic evidence is lacking. We recently identified a highly restricted neuronal population in mouse SSN. Ablation
of this neuronal population remarkably reduces lacrimation in mice, suggesting that this neuronal population
controls lacrimation. To test this hypothesis, we will first determine the efferent targets and physiological
properties of these SSN neurons (Aim 1). Results from these experiments will provide valuable information
regarding the encoding and transmission of lacrimal signals. Second, we will investigate the role of these SSN
neurons in controlling lacrimation by specific ablation or activation of this neuronal population (Aim 2). Results
from these experiments will provide functional evidence for SSN control of lacrimation. Finally, we will test these
SSN neurons receive sensory inputs from ocular surface and mediate reflex lacrimation (Aim 3). Results from
these experiments will help define previously unrecognized connections between ocular sensory inputs and SSN,
offering novel insights into the neural mechanism underlying the reflex lacrimation. In summary, our proposed
research will help reveal the neural circuit for lacrimation and provide foundational knowledge for future studies
of lacrimation deficiency associated with ocular or systemic diseases.

## Key facts

- **NIH application ID:** 10918315
- **Project number:** 5R01EY035261-02
- **Recipient organization:** WASHINGTON UNIVERSITY
- **Principal Investigator:** Qin Liu
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $464,776
- **Award type:** 5
- **Project period:** 2023-09-01 → 2028-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10918315

## Citation

> US National Institutes of Health, RePORTER application 10918315, Neural Circuits Controlling Lacrimation (5R01EY035261-02). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10918315. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*