# Calcium control of Neurotransmitter Release

> **NIH NIH R01** · YALE UNIVERSITY · 2023 · $369,277

## Abstract

Project Summary
Neurons communicate with each other by the quantal release of neurotransmitters stored in synaptic vesicles
(SVs), and the strength and efficacy of neurotransmitter release are dynamically altered during physiological
activity. This process is essential for learning and memory and is disrupted in many neurological disorders. The
neurotransmitter release occurs from a pool of SVs docked at the presynaptic active zone and is tightly controlled
by activity-dependent changes in the presynaptic calcium ions concentration ([Ca2+]). At nerve terminals, Ca2+-
sensing proteins (Synaptotagmins) couple vesicular release machinery (SNAREs) to Ca2+ signals, thus
orchestrating neuronal communication. Despite years of research, there remains a substantial gap between a
qualitative description of how the vesicle fusion machinery operates and the millisecond-precision and Ca2+-
dependent kinetics of neurotransmitter release observed at the neuronal synapses.
In this proposal, we describe the first systematic and comprehensive effort to reconcile the `molecular
biochemistry' of vesicle fusion with the `physiology' of Ca2+-evoked neurotransmitter release in the neuronal
synapses using a combination of complementary in vitro and in vivo experimental systems. Specifically, we aim
to resolve whether Synaptotagmin isoforms with distinct biochemical properties (Syt1 and Syt7), along with the
synaptic SNAREs represent the minimal protein machinery for different modes of neurotransmitter release and
short-term plasticity. We also propose to quantitatively test the hypothesis that the `dual-binding' of Syt1 and
Syt7 to SNAREs allows for synergistic regulation of vesicular release kinetics. For in vitro analysis, we will deploy
a biochemically-defined, high-throughput fusion system capable of tracking individual vesicle docking and Ca2+
triggered fusion on a millisecond timescale, which is integrated with fast Ca2+-uncaging protocols to generate
[Ca2+] transients mimicking presynaptic calcium dynamics. This will be complemented by physiological analysis
in cultured neurons utilizing fast, fluorescent glutamate sensor (iGluSnFR) and Ca2+ dyes to image quantal
glutamate release and presynaptic Ca2+ dynamics in individual presynaptic boutons with 2-4 millisecond temporal
resolution. We anticipate that this project will provide important insights into the molecular mechanisms
underlying neurotransmitter release and build toward a detailed mechanistic model of Ca2+-evoked synaptic
vesicle fusion. Overall, this will greatly enhance our understanding of neurotransmission and of how it is tuned
across different nerve cells allowing specific yet diverse communication in neuronal networks.

## Key facts

- **NIH application ID:** 10718229
- **Project number:** 1R01NS133091-01
- **Recipient organization:** YALE UNIVERSITY
- **Principal Investigator:** SHYAM S KRISHNAKUMAR
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2023
- **Award amount:** $369,277
- **Award type:** 1
- **Project period:** 2023-07-15 → 2028-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10718229

## Citation

> US National Institutes of Health, RePORTER application 10718229, Calcium control of Neurotransmitter Release (1R01NS133091-01). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10718229. Licensed CC0.

---

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