# Head Scanning Behavior and Reward Interactions in Potentiation of Place Fields

> **NIH NIH F31** · JOHNS HOPKINS UNIVERSITY · 2024 · $48,974

## Abstract

PROJECT SUMMARY
 A growing body of research implicates memory systems, such as the hippocampus, in reward
computations related to exploration and reward-seeking behaviors. Episodic memory formation relies on flexible
neural coding to form memories in changing environments. How are reward mechanisms involved in memory
formation within the hippocampus, a region required for episodic memory formation? Previous work has
suggested that hippocampal place cells—cells that fire at a specific location in the environment—overrepresent
goal locations where animals receive rewards. Further studies show that a subpopulation of place cells will form
fields and potentiate (i.e., increase their firing rate) at locations of head scanning, an investigatory behavior.
These studies, however, did not examine the mechanisms of rewards alone or unexpected reward changes in
evoking head scanning and place field formation. Although it is known that reward inputs preferentially project to
CA1 over CA3, how rewards evoke head scanning and subsequent place field formation across hippocampal
subfields CA1 and CA3 have not been explored.
 To test this relationship, I will use in vivo electrophysiology recordings via silicon probes in hippocampal
CA1 and CA3 during navigation tasks. Rewards will be delivered using an intracranial stimulating electrode to
the medial forebrain bundle, a region that projects from dopaminergic neurons in the ventral tegmental area to
the nucleus accumbens. For our first aim, I will evaluate the timescale and presence of goal overrepresentation
in CA1 and CA3. I will explore the hypothesis that head scans predict place field formation at rewarded goals
rapidly across both regions. For our second aim, I will assess the role of reward expectation in head scanning
exploration and place field potentiation. I will test the hypothesis that unexpected rewards will evoke more head
scanning and place field potentiation than expected rewards. Further, I will test how place field potentiation in
CA1 differs from that of CA3 at expected and unexpected reward locations. I expect that CA1 place fields will
potentiate more to unexpected increases in reward and weaken more to unexpected removal of reward than
CA3 place fields. By controlling reward delivery timing, this project will reveal the role of expected and
unexpected rewards in head scan initiation and place field formation. Together, the results of this project will
establish a spatiotemporal framework for reward exploration in episodic memory encoding. This project directly
investigates mechanisms of complex behaviors important for developing therapeutics aligned with the NIMH
mission. This proposal will support technical training endeavors, in electrophysiology, animal pose tracking, and
intracranial electrical stimulation. This fellowship will also provide training on science communication, reward
learning theory, data interpretation, sophisticated methods of statistical analysis, and academic career
d...

## Key facts

- **NIH application ID:** 10903141
- **Project number:** 1F31MH134596-01A1
- **Recipient organization:** JOHNS HOPKINS UNIVERSITY
- **Principal Investigator:** Pelin Ozel
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $48,974
- **Award type:** 1
- **Project period:** 2024-04-01 → 2026-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10903141

## Citation

> US National Institutes of Health, RePORTER application 10903141, Head Scanning Behavior and Reward Interactions in Potentiation of Place Fields (1F31MH134596-01A1). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10903141. Licensed CC0.

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