Functional strengthening through synaptic scaling upon connectivity disruption in neuronal cultures

Area of Science:

• Network Neuroscience
• Computational Neuroscience
• Cellular Neuroscience

Background:

• Understanding how neuronal networks remodel activity in response to damage is crucial but elusive.
• Investigating the impact of gradual synaptic blockade on effective connectivity in cortical networks is essential for network resilience studies.

Purpose of the Study:

• To investigate the remodeling of effective connectivity in cortical networks during gradual synaptic blockade.
• To quantify the changes in global efficiency (G_EFF) and identify mechanisms underlying network adaptation.

Main Methods:

• Utilized two configurations of neuronal cultures (130 neuronal aggregates and 600 individual neurons).
• Monitored spontaneous activity during progressive weakening of excitatory connectivity.
• Employed numerical simulations to explore the role of synaptic scaling in network plasticity.

Main Results:

• Observed a two-phase response in effective connectivity: initial transient strengthening followed by steady deterioration.
• Quantified a phenomenon termed 'hyperefficiency,' a 20-50% increase in global efficiency (G_EFF) during network deterioration.
• Numerical simulations confirmed that synaptic scaling, an activity-dependent plasticity mechanism, reproduces the observed hyperefficiency.

Conclusions:

• Synaptic scaling plays a critical role in counteracting perturbative actions in neuronal networks.
• This activity-dependent plasticity mechanism acts as a key resilience factor, maintaining network function under stress.
• The study highlights synaptic scaling's importance in neuronal network adaptation and stability.