# Mapping Brain Activity with High Spatiotemporal Resolution using Graphene Probes

> **NIH NIH R01** · VANDERBILT UNIVERSITY · 2020 · $391,637

## Abstract

Project Summary
 The central nervous system (CNS), the most complex and dynamic network found in nature, is composed
of billions of neurons with trillions of dendritic spines and synapses, including pre- and postsynaptic terminals.
The postsynaptic side of synapses can take the form of dendritic spines, which are small, actin-rich protrusions
that serve as sites of postsynaptic contact and signal integration for most of the excitatory synapses in the CNS.
Synapses relay signals between neighboring neurons in large neuronal networks, underscoring their vital
function in the CNS. Not surprisingly, abnormalities in dendritic spines/synapses are associated with a number
of CNS disorders, including Fragile-X syndrome, Down’s syndrome, Alzheimer’s disease, autism, schizophrenia,
and epilepsy, glaucoma, and intellectual disorders. It is, therefore, crucial to understand the relationships
between the functional connectivity map of neuronal networks and the physiological or pathological functions of
individual synapses and neurons. To address this challenge, we propose to integrate two-dimensional flexible
graphene membranes with scanning photocurrent microscopy to probe electrical activities of individual synapses
and neurons in the retina and brain, two of the three components of the CNS. A unique advantage of graphene
is that its whole volume is exposed to the environment, which maximizes its sensitivity to local electrochemical
potential change. For example, graphene transistors are capable of detecting individual gas molecules, due to
its high surface-area-to-volume ratio and high electron mobility (100 to 1000 times higher than silicon). The high
electron mobility also enables graphene transistors to operate at very high frequencies (up to 500 GHz), leading
to high temporal resolution. Because of its strength and flexibility, graphene membranes can adhere to cell
membranes or tissue slices to achieve high electrical sensitivity. Furthermore, monolayer graphene transmits
more than 97% of incident light, making it ideal to be used as transparent electrical devices that are compatible
with optical imaging techniques. In addition, graphene transistors and electrodes have demonstrated the
capability of stable operation at stretching up to 9%. As such, we propose to create an unprecedented
neurotechnology through a rare combination of flexible graphene transistors and scanning photocurrent
microscopy to simultaneously study the electrical activities of a large population of synapses and neurons in
vitro, in situ, and in vivo. This technology will allow us to decipher the functional connectivity map of neuronal
networks with high spatiotemporal resolution and high throughput.

## Key facts

- **NIH application ID:** 10002231
- **Project number:** 5R01EY027729-04
- **Recipient organization:** VANDERBILT UNIVERSITY
- **Principal Investigator:** Yaqiong Xu
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $391,637
- **Award type:** 5
- **Project period:** 2017-09-30 → 2022-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10002231

## Citation

> US National Institutes of Health, RePORTER application 10002231, Mapping Brain Activity with High Spatiotemporal Resolution using Graphene Probes (5R01EY027729-04). Retrieved via AI Analytics 2026-05-29 from https://api.ai-analytics.org/grant/nih/10002231. Licensed CC0.

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