# Dynamic modulation of postnatal development of preconfigured and plastic time-compressed sequences

> **NIH NIH R01** · YALE UNIVERSITY · 2022 · $418,750

## Abstract

Project summary: Of the multiple memory systems operating in the brain, episodic memory, defined by the
ability to remember where and when events occurred in the past, is a recently evolved, later developing and
early deteriorating cognitive function. Early-life episodic memories are rapidly forgotten, a phenomenon known
as infantile amnesia occurring in humans and non-human animals. The hippocampus, an evolutionarily
ancient, highly organized part of the cortex, is essential for the relational binding of spatial locations and events
into spatial and mental trajectories and memory episodes. The rapid encoding and consolidation of sequential
spatial experiences into memory episodes is believed to be achieved by the representation of such trajectories
within time-compressed hippocampal ‘place cell’ sequences during navigation and the sleep/rest periods
preceding (i.e., preplay, supporting rapid encoding) and following (i.e., replay, supporting consolidation) the
novel experiences. The hippocampus undergoes a developmental critical period and functionally matures
around postnatal day 24 (P24) in the rat, an age when infantile amnesia ends in rodents. Our main goal is to
explore and understand the dependence of memory development on intrahippocampal synaptic plasticity and
early-life experience by studying the development of ensemble place cell coding in the hippocampus. We
combine chronic electrophysiologic recording of large ensembles of neurons in awake-behaving and sleeping
rats across three recently described developmental stages in postnatal life with intra-hippocampal infusion of
enhancers of synaptic plasticity, rearing in enriched environments or early-life visual deprivation (dark rearing),
and computational methods for decoding spatial trajectories. The successful completion of our proposed aims
promises to uncover such developmental mechanism and factors in the rat, which should help understand the
development and emergence of episodic memories in the human, where such invasive approaches are not
possible. Our findings could more generally impact our understanding of developmental neuro-psychiatric brain
diseases like autism, schizophrenia, and intellectual disabilities.

## Key facts

- **NIH application ID:** 10450845
- **Project number:** 5R01MH121372-04
- **Recipient organization:** YALE UNIVERSITY
- **Principal Investigator:** GEORGE DRAGOI
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $418,750
- **Award type:** 5
- **Project period:** 2019-09-24 → 2024-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10450845

## Citation

> US National Institutes of Health, RePORTER application 10450845, Dynamic modulation of postnatal development of preconfigured and plastic time-compressed sequences (5R01MH121372-04). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10450845. Licensed CC0.

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