# Functional Integration of Medial Ganglionic Eminence Interneuron Transplants into Visual Cortex

> **NIH NIH F32** · UNIVERSITY OF CALIFORNIA, SAN FRANCISCO · 2020 · $65,640

## Abstract

Project Summary
 Transplantation of developing interneurons, specifically those expressing parvalbumin (PV) or
somatostatin (SST), into a host visual cortex has been shown to induce a new period of ocular dominance
plasticity (ODP). This newfound plasticity can also enhance the brain's ability to recovery from trauma;
interneuron transplantation has been shown to ameliorate phenotypes in animal models of epilepsy,
Parkinson's disease, and amblyopia. Given that specific changes in the activity of interneurons are known to
be essential for mediating plasticity in the normal critical period, it is necessary to study the activity of the
transplanted interneurons in order to understand the reintroduction of plasticity over the second critical period.
Here, I propose to study the functional integration of PV and SST transplanted interneurons in vivo as they
reopen the critical period for ODP. Aim 1 will determine the timeline for establishing and maintaining visually
driven responses in transplanted PV and SST interneurons that express a genetically encoded calcium
indicator. The intrinsic nature of this process will also be addressed by comparing the activity of PV and SST
transplanted interneurons to each other and to the older host interneurons. Aim 2 will identify how the
transplanted interneurons mediate ODP by studying how the activity timelines of PV and SST transplants are
affected when one eye is occluded (monocular deprivation) over the second critical period. To determine if the
activity of the transplants are causal for the induction of the second critical period, the firing properties of the
transplants will be manipulated in Aim 3. This will be achieved by activating either channelrhodopsin (a light-
activated non-specific cation channel that depolarizes neurons) or archaerhodopsin (a light-activated proton
pump that hyperpolarizes neurons) in the respective transplanted interneuron at time points of interest reported
for endogenous interneurons over the normal critical period and from the activity timeline in Aim 2. The ability
of transplanted interneurons to induce plasticity de novo offers a powerful tool to study the mechanisms and
limits of cortical plasticity.

## Key facts

- **NIH application ID:** 9857475
- **Project number:** 5F32EY029935-02
- **Recipient organization:** UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
- **Principal Investigator:** Benjamin Rakela
- **Activity code:** F32 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $65,640
- **Award type:** 5
- **Project period:** 2019-02-01 → 2022-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9857475

## Citation

> US National Institutes of Health, RePORTER application 9857475, Functional Integration of Medial Ganglionic Eminence Interneuron Transplants into Visual Cortex (5F32EY029935-02). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9857475. Licensed CC0.

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