# Continuous and Longitudinal Monitoring of Cerebral Blood Flow and Metabolism in Freely Moving Rodents

> **NIH NIH R56** · UNIVERSITY OF KENTUCKY · 2020 · $612,754

## Abstract

ABSTRACT
Measurements of cerebral blood flow (CBF) and cerebral metabolic rate of oxygen consumption (CMRO2) in
response to brain activity allows investigation of underlying excitatory and inhibitory neural responses and holds
the key to optimizing novel therapies for neurological disorders and cerebrovascular diseases. Rodents (mice
and rats) have been helping scientists investigate human diseases for well over a century and still make up 95%
of the animal models used today. Major limitations with these rodent models are that cerebral hemodynamics is
measured mostly in anesthetized animals and at limited time points. However, anesthesia impacts cerebral
hemodynamics profoundly and interferes with studies of behavioral health, cognitive function, and sleep disorder.
A few methods available for cerebral hemodynamic monitoring in conscious rodents require invasive craniotomy
with installation of various opto-electrode/ultrasound probes onto the brain, which restrains animal’s head or
body during measurements. Supported by NIH (R21), we have recently developed an innovative, noninvasive,
low-cost, fiber-free, near-infrared diffuse speckle contrast flowmetry (DSCF) probe, which affixes on the heads
of anesthetized rodents and awake humans for continuous monitoring of CBF. The goal of this proposal is to
extend, optimize, and validate this novel technology toward a dual-wavelength, multi-channel, diffuse speckle
contrast flow-oximetry (DSCFO) system for simultaneous regional mapping of CBF, cerebral oxygenation, and
CMRO2 in conscious, freely moving rodents. DSCFO uses small near-infrared laser diodes at different
wavelengths as point sources and a tiny CMOS camera as a 2D detector array to detect spatial dynamic light
scattering by intrinsic motions of red blood cells (i.e., CBF) and light attenuations by oxy- and deoxy- hemoglobin
absorptions ([HbO2] and [Hb]). Combination of CBF, [HbO2], and [Hb] enables derivation of CMRO2 based on
established models. The 2D camera array enables 2D mapping of cerebral responses over two hemispheres
and at different depths of the rodent head. Importantly, connections between the DSCFO probe and control unit
are all electrical wires/cables (i.e., fiber-free), thereby offering the promise for continuous cerebral monitoring in
freely moving subjects. After calibrating and optimizing the DSCFO system using head-simulating phantoms and
validation in anesthetized rodents against established techniques, we will evaluate its performance for
continuous and longitudinal cerebral monitoring in conscious, freely moving rodents with or without ischemic
stroke insult. While we explore stroke-induced cerebral outcomes in this project, the DSCFO technology is
applicable for studying other neurological disorders and cerebrovascular diseases. In combination with our
ongoing R21 studies in human subjects, completion of this study in rodents will generate a unique noninvasive,
fast, low-cost, multiscale, and multimodal brain mapping t...

## Key facts

- **NIH application ID:** 10204279
- **Project number:** 1R56NS117587-01
- **Recipient organization:** UNIVERSITY OF KENTUCKY
- **Principal Investigator:** Guoqiang Yu
- **Activity code:** R56 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $612,754
- **Award type:** 1
- **Project period:** 2020-09-01 → 2023-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10204279

## Citation

> US National Institutes of Health, RePORTER application 10204279, Continuous and Longitudinal Monitoring of Cerebral Blood Flow and Metabolism in Freely Moving Rodents (1R56NS117587-01). Retrieved via AI Analytics 2026-07-19 from https://api.ai-analytics.org/grant/nih/10204279. Licensed CC0.

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