Postsynaptic element contributes to the delay in synaptogenesis in synapsin I-deficient neurons

Area of Science:

• Neuroscience
• Cell Biology
• Synaptic Plasticity

Background:

• Previous research indicated impaired process outgrowth and synapse formation in synapsin I-deficient mouse hippocampal neurons.
• The precise role of synapsin I in presynaptic versus postsynaptic development remained unclear.

Purpose of the Study:

• To determine if the synaptogenesis delay in synapsin I-deficient neurons is due to presynaptic or postsynaptic factors.
• To elucidate the specific contribution of synapsin I to synaptic maturation.

Main Methods:

• Utilized heterochronic cocultures of wild-type and synapsin I-deficient hippocampal neurons.
• Assessed synapse formation and maturation over time in mixed neuronal cultures.

Main Results:

• Wild-type presynaptic elements formed synapses with postsynaptic elements after 24 and 72 hours.
• Synapsin I-deficient postsynaptic elements exhibited a significant 5-day delay in receiving synapses, requiring 9 days for maturation.
• Presynaptic synapsin I-deficient neurons showed normal synapse formation with mature postsynaptic targets.

Conclusions:

• Synapsin I plays a critical role in the maturation of postsynaptic elements, causing a delay in synapse formation when deficient.
• The findings suggest synapsin I is essential for both presynaptic and postsynaptic development, broadly influencing synapse structural maturation.