# Gene Transfer for Cataplexy of Narcolepsy

> **NIH NIH R01** · MEDICAL UNIVERSITY OF SOUTH CAROLINA · 2020 · $369,888

## Abstract

Abstract
 I am a new young investigator with a proven publication record who is using new tools to correct
specific circuits in the sleep disorder, narcolepsy. This disorder is linked to a specific loss of neurons
containing the neuropeptide orexin, also known as hypocretin. Mine was the first study to demonstrate that
orexin gene transfer into the brains of narcoleptic mice blocks cataplexy. Indeed, orexin gene transfer into
some neuron populations in the CNS has proven to be ineffective indicating that only specific surrogate
neurons can repair narcoleptic behavior. This project will continue to focus on cataplexy, an important
distinguishing symptom of narcolepsy. Cataplexy is a sudden loss of muscle tone during waking and it is
often triggered by strong emotions, including both positive (e.g. laughter, humor) and negative (e.g. anger,
fear or sudden surprise) emotions. It is not known how emotions trigger cataplexy. I seek to identify this
circuit by combining orexin gene transfer, optogenetics and novel brain circuit mapping tools that restrict
expression of specific genes to phenotype and projection-specific neurons. The overall hypothesis driving the
aims is that during strong emotions GABA input from the central nucleus of the amygdala (CeA) to the
dorsolateral pons (vlPAG/LC/LPT) triggers cataplexy by inhibiting the pontine circuit responsible for
maintaining muscle tone. Preliminary data supports this hypothesis because optogenetic inhibition or
insertion of orexin into the CeA amygdala neurons projecting to the vlPAG/LC/LPT decreases emotion-
induced cataplexy. Five aims are proposed to test the overall hypothesis. The proposed aims are mutually
supporting, hypothesis driven, with clear objectives and definite endpoints. Extensive preliminary data show
support for the hypothesis and feasibility of the approach. At the end of the funding period the project will
have identified a meaningful neural circuit. This will have a significant impact in the development of potential
therapies, including pharmacological agents, that can be selectively directed to this circuit.

## Key facts

- **NIH application ID:** 9955364
- **Project number:** 5R01NS096151-05
- **Recipient organization:** MEDICAL UNIVERSITY OF SOUTH CAROLINA
- **Principal Investigator:** Meng Liu
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $369,888
- **Award type:** 5
- **Project period:** 2016-09-15 → 2023-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9955364

## Citation

> US National Institutes of Health, RePORTER application 9955364, Gene Transfer for Cataplexy of Narcolepsy (5R01NS096151-05). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/9955364. Licensed CC0.

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