# Thalamocortical Circuits Governing Egocentric-Allocentric Spatial Reference Frame Transformations

> **NIH NIH F32** · BOSTON UNIVERSITY (CHARLES RIVER CAMPUS) · 2024 · $74,284

## Abstract

PROJECT SUMMARY/ABSTRACT
Sensory information enters the brain from a first-person, egocentric perspective. However, behavioral studies of
spatial memory, and the discovery of spatial cell types such as place cells in the hippocampus and grid cells in
the medial entorhinal cortex (MEC), imply that the brain binds such egocentric information to a world-centered,
allocentric reference frame. One potential framework for this transformation involves a recently characterized,
evolutionarily ancient pathway that conveys visual information from the superior colliculus to the postrhinal cortex
(POR; homolog of the human parahippocampal cortex) via the lateral posterior thalamus (LP; homolog of the
pulvinar). POR in turn sends strong projections to MEC, thought to contribute to the construction of allocentric
spatial maps. While egocentric and allocentric spatial correlates have been discovered among POR neurons,
the specific LP inputs that produce POR spatial firing are unknown, as are the mechanisms involved in
transforming POR egocentric representations into MEC allocentric representations. The proposed experiments
will seek to elucidate the neural mechanisms involved in transforming egocentric visual information into
allocentric spatial representations along the pathway involving LP, POR, and MEC. Dual-site in vivo
electrophysiology along with chemogenetic silencing of neural activity will be used to characterize functional and
temporal connectivity between LP and POR, as well as the reliance of POR spatial representations on LP
function. We also propose experiments combining computational modeling with simultaneous Neuropixels
recordings from POR and MEC neurons during visual cue manipulations to identify the elements of POR cell
firing that may create or support the firing of grid and non-grid spatial cells in MEC. The completion of these
experiments will provide significant insight into how sensory information undergoes neural processing to guide
spatial memory and behavior, as well as the mechanisms underlying deficits seen with damage to these brain
areas including Alzheimer’s disease and topographical disorientation.

## Key facts

- **NIH application ID:** 11068562
- **Project number:** 1F32MH139270-01
- **Recipient organization:** BOSTON UNIVERSITY (CHARLES RIVER CAMPUS)
- **Principal Investigator:** Patrick Adam LaChance
- **Activity code:** F32 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $74,284
- **Award type:** 1
- **Project period:** 2024-09-30 → 2027-09-29

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/11068562

## Citation

> US National Institutes of Health, RePORTER application 11068562, Thalamocortical Circuits Governing Egocentric-Allocentric Spatial Reference Frame Transformations (1F32MH139270-01). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/11068562. Licensed CC0.

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