Palmitoylation of PSD-95 Orchestrates Learning-Dependent Metaplasticity in the Amygdala and Fear Memory

Area of Science:

• Neuroscience
• Molecular Biology
• Synaptic Plasticity

Background:

• Palmitoylation's role in learning and memory is not fully understood.
• Specific mechanisms linking palmitoylation to synaptic plasticity and memory remain elusive.

Purpose of the Study:

• To investigate the role of palmitoylation in amygdalar synaptic plasticity and fear memory.
• To elucidate the underlying molecular mechanisms involving PSD-95 and palmitate cycling.

Main Methods:

• Multi-methodological experiments were employed.
• Investigated metaplasticity in the amygdala and hippocampus following fear conditioning.
• Analyzed the role of PSD-95 palmitoylation in lateral amygdala (LA) synapses.
• Examined the involvement of DHHC2 and PICK1 in the pathway.

Main Results:

• Conditioned fear learning impairs amygdalar metaplasticity, unlike in the hippocampus.
• PSD-95 palmitoylation is crucial for fear memory expression and occludes Long-Term Potentiation (LTP) at LA synapses.
• The PICK1-DHHC2-PSD-95 pathway regulates LA synaptic plasticity and fear memory.

Conclusions:

• Palmitoylation, via the PICK1-DHHC2-PSD-95 pathway, is a key regulator of learning-dependent metaplasticity in the amygdala.
• This pathway influences synaptic plasticity, occludes LTP, and promotes fear memory expression.