# Integrated Cerebral Blood Flow Regulation

> **NIH NIH R01** · UNIVERSITY OF NEVADA RENO · 2024 · $391,753

## Abstract

The brain requires a continuous supply of nutrients and oxygen to fuel its normal functioning. Active areas of the
brain need more energy than relatively quiescent regions, so the blood supply to different areas of the brain is
dynamically varied over time to meet the ongoing needs of active neurons. Significant progress has been made
in understanding the essential role of localized synaptic glutamatergic signaling in regulating local cerebral blood
flow (CBF) in response to increased neuronal activity, a process known as neurovascular coupling (NVC).
However, little is currently known about the integration between neural (i.e., neurons and astrocytes) and
vascular networks and the broader mechanisms underlying the spatiotemporal coordination of local and global
vascular responses within the cortical angioarchitecture and among different brain regions. The overall goal of
this proposal is to identify interactions between local and global signaling pathways that control the magnitude
and distribution of blood to match metabolic demands. Our preliminary data show that the state of wakefulness
and engagement of the animal that are often associated with the release of long-range modulatory
neurotransmitters (e.g., serotonin [5-HT]), and that manipulations of 5-HT activity modulate vascular responses.
We propose that glutamatergic and serotonergic signaling are integrated to control CBF. Our data further suggest
that vascular conduction may mediate ascending vasomotor responses from the deep layer to upstream
parenchyma and the surface of the cortex to coordinate blood flow. On the basis of these observations, we
propose a new paradigm in which activity-dependent allocation of CBF depends on the integration of three
elements: 1) local synaptic glutamatergic signaling, 2) the global serotonergic system, and 3) retrograde
intercellular conduction. We will employ two-photon fluorescence imaging of the vasculature and Ca2+ dynamics
in neurons and astrocytes in fully awake animals in conjunction with ex vivo preparations, knockout strategies,
genetically encoded biosensors, pharmacogenetics and optogenetics to test this paradigm. These integrated
approaches are novel and powerful as they give us the ability to fully explore the integration of different signaling
pathways under true physiological conditions without the need for anesthetics. Aim 1 will explore the contribution
of serotonergic signaling to sensory-induced increases in local CBF and to coordination of blood distribution
between inactive and active regions. Aim 2 will elucidate the mechanisms underlying 5-HT–induced vasomotor
responses during whisker stimulation. Aim 3 will solidify the role of the endothelium in conducting electrical
signals from the subsurface microvascular network to the upstream parenchyma and surface of the cortex, a
process that is proposed to complement NVC. Our investigation into this novel model may reveal new
physiological processes essential to CBF regulation and ult...

## Key facts

- **NIH application ID:** 10740883
- **Project number:** 5R01NS121543-03
- **Recipient organization:** UNIVERSITY OF NEVADA RENO
- **Principal Investigator:** Cam Ha Thai Tran
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $391,753
- **Award type:** 5
- **Project period:** 2021-12-01 → 2026-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10740883

## Citation

> US National Institutes of Health, RePORTER application 10740883, Integrated Cerebral Blood Flow Regulation (5R01NS121543-03). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10740883. Licensed CC0.

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