# Imaging excitatory synaptic input to hippocampal dendritic segments during spatial navigation

> **NIH NIH F32** · NORTHWESTERN UNIVERSITY · 2021 · $35,229

## Abstract

Imaging excitatory synaptic input to hippocampal dendritic segments during spatial navigation
Heydar Davoudi, Department of Neurobiology, Northwestern University
Project Summary/Abstract
The hippocampus has a critical role in spatial navigation and formation of episodic memories. Hippocampal
output area CA1 is crucial for spatial learning and memory and it receives major excitatory inputs from
entorhinal cortex (EC) through the Perforant pathway (PP) and from hippocampal areas CA2 and CA3 through
the Schaffer collateral (SC) pathways. During exploration, a rodent’s CA1 neurons show location-specific activity
known as place fields of these “place cells”. CA1 place fields may be driven by PP and SC input pathways
arriving on CA1 dendritic spines. However, it is unknown what different roles these two pathways play in
driving the CA1 place cell activity necessary for spatial learning and memory. Here, I propose to develop a
previously-unattainable simultaneous dual-color two-photon functional imaging of a CA1 place cell soma and
its synaptic-scale excitatory input in head-fixed mice navigating through a virtual-reality environment. I aim to
develop microprism-based and Bessel beam-based two-photon microscopies to image a CA1 place cell soma and
the synaptic-scale excitatory input to its basal and distal tuft dendritic segments, which respectively receive
inputs from SC and PP pathways. This allows me to determine how the different excitatory synaptic inputs
carried by these two pathways differentially contribute to somatic place fields in a familiar track and during
learning a new virtual environment. Altogether, this proposal aims to add to our understanding of synaptic-
level cognitive processing which is disrupted in neurological and psychiatric diseases such as Alzheimer’s
disease and schizophrenia.

## Key facts

- **NIH application ID:** 10396808
- **Project number:** 3F32NS116023-02S1
- **Recipient organization:** NORTHWESTERN UNIVERSITY
- **Principal Investigator:** Heydar Davoudi
- **Activity code:** F32 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $35,229
- **Award type:** 3
- **Project period:** 2021-09-01 → 2022-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10396808

## Citation

> US National Institutes of Health, RePORTER application 10396808, Imaging excitatory synaptic input to hippocampal dendritic segments during spatial navigation (3F32NS116023-02S1). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10396808. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*