# Understanding the effects of experimental brain injury to extinction of active avoidance

> **NIH NIH R21** · UNIVERSITY OF PUERTO RICO MED SCIENCES · 2021 · $182,802

## Abstract

Project Summary (from parent grant R21 NS119991)
 Our goal is to address an emerging challenge that we face with the effects of brain injury to
neurological function and mental health. A broad class of brain damage is diffuse injury (e.g.
concussion) produced experimentally using a closed head injury by weight drop onto the head.
Concussion occurs with an impact to the head plus angular acceleration which may result in
axonal damage that disrupts communication and activity between brain regions, likely affecting
mental health by impairing emotional regulation. Two important forms of emotional regulation
are extinction and avoidance of rewarding stimuli. Extinction is the basis of exposure treatment
for fear and anxiety disorders. Avoidance of situations that trigger fear memories is a hallmark
of many mental health disorders. Patients with brain injury display excess avoidance, thus
reducing the attainment of rewards, which is detrimental to recovery. To evaluate the potential
relationship between brain injury and avoidance, a biological link must be examined using
reliable injury models and behavioral tests. There are homologous brain regions in rodents and
humans for avoidance. Avoidance requires interactions between the amygdala, medial
prefrontal cortex, and ventral striatum. Overall, this work will answer a series of key questions
about the impact of brain injury to extinction and avoidance. Moreover, this work will increase
the base of scientific and public health evidence on this important subject.

## Key facts

- **NIH application ID:** 10353745
- **Project number:** 3R21NS119991-01S1
- **Recipient organization:** UNIVERSITY OF PUERTO RICO MED SCIENCES
- **Principal Investigator:** Demetrio Sierra
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $182,802
- **Award type:** 3
- **Project period:** 2021-04-01 → 2025-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10353745

## Citation

> US National Institutes of Health, RePORTER application 10353745, Understanding the effects of experimental brain injury to extinction of active avoidance (3R21NS119991-01S1). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10353745. Licensed CC0.

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