Host interneurons mediate plasticity reactivated by embryonic inhibitory cell transplantation in mouse visual cortex

Area of Science:

• Neuroscience
• Developmental Neuroscience
• Cortical Plasticity

Background:

• Adult brains exhibit reduced sensitivity to environmental changes compared to juvenile brains.
• Embryonic interneuron transplantation can restore plasticity in the adult visual cortex.
• The precise mechanism of transplant-induced plasticity (direct vs. indirect) remains unclear.

Purpose of the Study:

• To determine if transplanted interneurons directly mediate plasticity or indirectly modify host circuitry.
• To investigate the role of Neuregulin (NRG1)/ErbB4 signaling in transplant-induced cortical plasticity.

Main Methods:

• Utilized mouse models with transplanted embryonic interneurons into the adult visual cortex.
• Examined the effects of visual deprivation on host and transplanted parvalbumin (PV) interneurons.
• Manipulated Neuregulin (NRG1)/ErbB4 signaling in host and donor PV interneurons.
• Assessed cortical plasticity through circuit reorganization and visual response changes.

Main Results:

• Transplant-induced circuit reorganization is mediated by NRG1/ErbB4 signaling specifically in host PV interneurons.
• Visual deprivation reduces host PV interneuron activity, but not transplanted PV interneuron activity.
• Exogenous NRG1 prevents activity reduction and blocks transplant-induced plasticity.
• Deleting ErbB4 from host PV interneurons abolishes plasticity; deleting from donor PV interneurons has no effect.

Conclusions:

• Transplanted interneurons reactivate cortical plasticity by rejuvenating host PV interneuron function.
• NRG1/ErbB4 signaling in host PV interneurons is essential for restoring plasticity after interneuron transplantation.