# Hippocampal-dependent spatial memory encoding during attentive processing from place

> **NIH NIH R21** · TRUSTEES OF INDIANA UNIVERSITY · 2024 · $237,750

## Abstract

Project Summary / Abstract
Spatial memory is a core competency necessary for healthy independent living and for animal survival. While
the hippocampus is well-established to be necessary for spatial memory, it remains poorly understood when
and what the hippocampus does to support spatial memory. Studies of hippocampal function in rodents have
focused predominantly on epochs of locomotion and quiet rest. Minimal attention has been given to the
ubiquitously observed non-locomotor exploratory behavior of rearing onto the hind legs (rearing for short).
Rearing occurs most frequently in novel environments, correlates with environmental learning, and engages
rhythmic processing in the hippocampus. Yet, it remains untested whether epochs of rearing are necessary for
spatial memory performance and what updates to the neuronal population code result from rearing. This
project will address these gaps with new empirical experiments. Our focus on rearing is motivated by our new
preliminary data showing that inhibiting the dorsal hippocampus selectively during rearing impairs spatial
memory. Aim 1 will establish the importance of rearing as an epoch of hippocampal dependent spatial memory
encoding in relation to other well-studied behavioral epochs. We will accomplish this through closed-loop
optogenetic modulation of hippocampal activity and behavioral analysis in rats. Aim 2 will test the hypothesis
that rearing supports error correction of spatial coding in the hippocampus. This will be accomplished through
chronically implanted arrays of independently movable tetrodes in freely behaving rats. By the completion of
these aims, this project will advance our mechanistic understanding of spatial memory and for our
understanding of rearing as an epoch of mnemonic encoding. If successful, these results will lay the foundation
for an R01-level program of research investigating the mechanistic basis of the rearing-mediated learning
effect and the relevance of rearing-mediated learning for memory disorders and mental health.

## Key facts

- **NIH application ID:** 10789223
- **Project number:** 1R21MH135251-01
- **Recipient organization:** TRUSTEES OF INDIANA UNIVERSITY
- **Principal Investigator:** Ehren L. Newman
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $237,750
- **Award type:** 1
- **Project period:** 2023-12-18 → 2025-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10789223

## Citation

> US National Institutes of Health, RePORTER application 10789223, Hippocampal-dependent spatial memory encoding during attentive processing from place (1R21MH135251-01). Retrieved via AI Analytics 2026-05-27 from https://api.ai-analytics.org/grant/nih/10789223. Licensed CC0.

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