# A novel hippocampal GABAergic projection and its potential role in spatial recognition

> **NIH NIH F31** · UNIVERSITY OF MINNESOTA · 2022 · $33,886

## Abstract

Project Summary
Identifying novelty or familiarity of the environment is required for spatial navigation and influences forming and
maintaining internal spatial maps. This process of identifying an environment as novel or familiar and forming
the appropriate spatial map is impaired in aging rodents and in rodent models of Alzheimer’s disease and
temporal lobe epilepsy, possibly reflecting spatial processing deficits in patient populations. Recently identified
spatial novelty signals from the supramammillary area to the hippocampal dentate gyrus (SuM→DG) shape
spatial processing in the hippocampus; however, what signals influence SuM spatial novelty signals is
unknown.
This proposal investigates a novel hippocampal CA1 GABAergic projection to the SuM and its potential role in
signaling spatial recognition and suppressing SuM spatial novelty signals. I term these cells HIPS
(hippocampal inhibitory cells projecting to the supramammillary area), and my preliminary data indicates their
fibers are near SuM→DG neurons. This proposal tests the hypothesis that HIPS signal spatial recognition,
inhibit SuM→DG neurons, and influence spatial processing. I am proposing three aims to analyze the
functional connectivity, behavioral impact, and in vivo activity of HIPS. I will utilize slice electrophysiology
combined with optogenetic stimulation of HIPS to analyze HIPS connections to SuM→DG neurons and other
neurons of the SuM (Aim 1) to test if HIPS have functional, inhibitory connections to the SuM and to test if
HIPS preferentially inhibit SuM→DG neurons. To test HIPS impact on behavior and memory, I will apply in vivo
optogenetics to stimulate HIPS in behavioral tasks which vary spatial and non-spatial familiarity and novelty
(Aim 2). I will additionally use head-mounted miniature microscopes to perform in vivo calcium imaging of HIPS
in freely behaving mice to test if HIPS’ activity reflects spatial recognition (Aim 3).
This proposal provides insight into a novel hippocampal GABAergic projection and potential circuits involved in
spatial recognition. This work also gives me the excellent opportunity to train in analysis of cells, circuits, and
behavior using techniques which have all been successfully applied in the lab of my sponsor, Dr. Esther Krook-
Magnuson. My sponsor and co-sponsor, Dr. David Redish, will fully support me in the knowledge and technical
skills required for the proposal, and they are each committed to my development of professional skills needed
for an academic research career. Their support combined with the resources of the University of Minnesota
Graduate Program in Neuroscience will fully prepare me to pursue a career as an independent researcher.

## Key facts

- **NIH application ID:** 10462880
- **Project number:** 1F31NS127417-01
- **Recipient organization:** UNIVERSITY OF MINNESOTA
- **Principal Investigator:** Lauren Glassburn
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $33,886
- **Award type:** 1
- **Project period:** 2022-06-21 → 2025-06-20

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10462880

## Citation

> US National Institutes of Health, RePORTER application 10462880, A novel hippocampal GABAergic projection and its potential role in spatial recognition (1F31NS127417-01). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10462880. Licensed CC0.

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