# Circuits driving spatial coding deficits in epilepsy

> **NIH NIH R01** · ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI · 2021 · $46,818

## Abstract

Project Summary/Abstract
Temporal lobe epilepsy (TLE) is a debilitating disorder that includes pervasive memory impairments that
significantly impact quality of life. In rodent models of TLE, my lab and others have found major deficits in
learning and memory as well as in the precision and stability of CA1 place cells. However, it remains unclear
whether impaired spatial coding in CA1 is primarily due to local processing deficits in hippocampus or rather is
influenced by impaired spatial coding and synchronization from upstream inputs. In fact, there is significant
evidence that upstream inputs into the hippocampus from the medial entorhinal cortex (MEC) may be altered in
epilepsy. This proposal will test the hypothesis that the indirect inputs into hippocampus from MECII are
specifically altered in epileptic mice. To test this hypothesis, we will first use calcium imaging with miniature
microscopes to characterize how chronic epilepsy alters spatial coding in MECII stellate cells and MECIII
neurons, which directly input into hippocampus. Next, we will use silicon probes to record interneuron firing and
LFPs simultaneously in MECII, MECIII, DG, and CA1 and determine how synchronization throughout the
entorhinal-hippocampal circuit is altered in epileptic mice. Finally, we will use excitatory and inhibitory
DREADDs to modulate MECII stellate cells and determine how this input into hippocampus alters
synchronization of hippocampal circuits and spatial memory. Together, these aims will use state-of-the-art
recording and manipulation techniques to determine precisely where and how spatial coding and
synchronization breaks down in epileptic mice and gain new insights into the cause of cognitive deficits.

## Key facts

- **NIH application ID:** 10405986
- **Project number:** 3R01NS116357-01A1S1
- **Recipient organization:** ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI
- **Principal Investigator:** Tristan Shuman
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $46,818
- **Award type:** 3
- **Project period:** 2021-07-01 → 2024-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10405986

## Citation

> US National Institutes of Health, RePORTER application 10405986, Circuits driving spatial coding deficits in epilepsy (3R01NS116357-01A1S1). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10405986. Licensed CC0.

---

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