Early depolarizing GABA controls critical-period plasticity in the rat visual cortex

Area of Science:

• Neuroscience
• Developmental Biology
• Neuroplasticity

Background:

• Inhibitory neurotransmission mediated by GABA is crucial for regulating critical periods of plasticity in sensory cortices.
• While hyperpolarizing GABA is known to be inhibitory, the role of early depolarizing GABA in plasticity control remains less understood.

Purpose of the Study:

• To investigate the function of early, depolarizing GABA in the regulation of plasticity mechanisms during early development.
• To determine the long-term effects of manipulating depolarizing GABA on visual cortical circuits and associated molecular regulators.

Main Methods:

• Brief interference with depolarizing GABA during early development in a model system.
• Assessment of critical-period plasticity in visual cortical circuits.
• Analysis of inhibitory neurotransmission, brain-derived neurotrophic factor (BDNF) expression, and extracellular matrix perineuronal net density.
• Pharmacological manipulation of BDNF signaling during GABA interference.

Main Results:

• Interference with depolarizing GABA prolonged critical-period plasticity without impacting overall visual system development.
• This manipulation led to dampened inhibitory neurotransmission, reduced BDNF expression, and decreased perineuronal net density.
• Early GABA interference decreased perinatal BDNF signaling, which could be rescued by pharmacologically increasing BDNF signaling.

Conclusions:

• Depolarizing GABA plays a significant role in the long-lasting, selective modulation of cortical circuit plasticity.
• A strong crosstalk between depolarizing GABA and BDNF signaling is critical for regulating plasticity during development.