# The Impact of Third Trimester Alcohol Exposure on Memories Encoded by Sharp-Wave Ripples of the Hippocampal-Retrosplenial Cortex Circuit

> **NIH NIH F31** · UNIVERSITY OF NEW MEXICO HEALTH SCIS CTR · 2024 · $39,563

## Abstract

Project Summary
Fetal alcohol spectrum disorder (FASD), which occurs when a fetus is exposed to alcohol, is a
neurodevelopmental disorder affecting up to 5% of the US population. One of the most devastating outcomes
for children with FASD are learning and memory deficits, the mechanisms of which are little understood.
Essential for learning and memory, sharp wave ripples (SWRs) are high frequency neural oscillatory events
observed in the CA1 region of the hippocampus that travel to the retrosplenial cortex (RSC). Third trimester
alcohol exposure (TTAE) in particular leads to severe neuronal death in the RSC and dysfunction in neuronal
populations necessary for SWR formation. Despite this clear damage, little is known about how TTAE affects
SWRs in the RSC. To fill this gap in knowledge, I propose the use of a mouse model of TTAE together with in
vivo electrophysiology and optogenetics to investigate the effects on SWR characteristics across learning.
Electrodes will be implanted in the CA1 and RSC, allowing for data collection while navigating a Barnes maze
(BM) spatial navigation learning and memory task. Recordings will continue for 24 hours following the end of
the task each day to gather SWRs that occur during Non-Rapid Eye Movement (NREM) sleep when memories
are consolidated. Multiple analytical tools will be used to investigate the impact of TTAE on two key SWR
features - amplitude and duration. Additional tools will be used to assess the firing rates and waveforms of
individual neurons, to determine the impact of TTAE on the recruitment of excitatory versus inhibitory neurons
by SWRs and the “replay” of these neurons during NREM. A separate and smaller subset of subjects will
undergo optogenetic induction of SWRs, principally to evaluate if TTAE leads to alterations in SWR CA1
induction thresholds and/or propagation rates from CA1 to RSC. Collectively, this proposal will determine the
functional mechanisms of key phases of learning and the role of SWRs to these phases: Acquisition,
consolidation, retrieval and plasticity. The successful completion of this proposal will provide critical information
on the lasting neurological impacts of TTAE on SWRs in the RSC, and how this may affect learning and
memory. Additionally, this work will provide intensive training in awake/behaving electrophysiology,
optogenetics, and a wide variety of analytical tools.

## Key facts

- **NIH application ID:** 10998804
- **Project number:** 1F31AA031916-01
- **Recipient organization:** UNIVERSITY OF NEW MEXICO HEALTH SCIS CTR
- **Principal Investigator:** Abbey Myrick
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $39,563
- **Award type:** 1
- **Project period:** 2024-09-01 → 2027-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10998804

## Citation

> US National Institutes of Health, RePORTER application 10998804, The Impact of Third Trimester Alcohol Exposure on Memories Encoded by Sharp-Wave Ripples of the Hippocampal-Retrosplenial Cortex Circuit (1F31AA031916-01). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10998804. Licensed CC0.

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