The transplantation of embryonic inhibitory neurons has recently emerged as a promising avenue for cell-based brain repair. Previously, we and others have shown that transplanted inhibitory neurons restore juvenile plasticity to the circuits of adult visual cortex. In this study, we set out to elucidate the mechanisms for transplant-induced cortical plasticity. We hypothesize that transplanted inhibitory neurons reactivate plasticity by creating a new, disinhibitory microcircuit in recipient adult visual cortex. First, we will map out the effects of transplantation on the inter- and intralaminar balance of excitation and inhibition. Next, we will compare the cell-type specific effects of brief monocular deprivation on visual activity in host cortex. Lastly, we will test whether transplanted neurons make long-range connections with appropriate circuits. To evaluate these hypotheses, this proposal will take advantage of recent advances in optogenetic dissection of inhibitory circuits in brain slice, multiphoton imaging of defined cortical cell types using genetically encoded calcium indicators, chemical-genetic tools for testing the mechanisms of transplant- induced plasticity and viral tracing and whole brain clearing to identify the brain-wide connections onto transplanted cells. If successful, the proposed studies shed light on the mechanisms of transplant-induced cortical reorganization. These studies are also likely to give insight into the normal developmental regulation of cortical plasticity by inhibitory cells.

Public Health Relevance

The adult brain lacks the capacity to reorganize itself that is abundant in the juvenile brain. We have previously shown that the transplantation of a specific type of embryonic neural cells into the adult visual system restores juvenile brain plasticity and reverses deficits caused by inadequate childhood visual experience. We will investigate how these transplanted cells restore plasticity by studying their functional and anatomical contribution to the host brain. Our studies will also provide basic insight into the mechanisms of juvenile brain plasticity.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY029490-02
Application #
9919570
Study Section
Neurodifferentiation, Plasticity, and Regeneration Study Section (NDPR)
Program Officer
Greenwell, Thomas
Project Start
2019-05-01
Project End
2024-04-30
Budget Start
2020-05-01
Budget End
2021-04-30
Support Year
2
Fiscal Year
2020
Total Cost
Indirect Cost
Name
University of California Irvine
Department
Other Basic Sciences
Type
Schools of Arts and Sciences
DUNS #
046705849
City
Irvine
State
CA
Country
United States
Zip Code
92617