Bursting reverberation as a multiscale neuronal network process driven by synaptic depression-facilitation.

Area of Science:

• Neuroscience
• Computational Neuroscience
• Systems Neuroscience

Background:

• Neuronal networks exhibit complex activity patterns influenced by individual neuron properties and synaptic connections.
• Understanding how synaptic dynamics and network connectivity shape emergent network behavior is crucial.

Purpose of the Study:

• To investigate the impact of synaptic properties and connectivity on neuronal network behavior.
• To explain the scale-dependent differences in reverberating activity duration between small neuronal ensembles and hippocampal slices.

Main Methods:

• Investigated neuronal ensemble responses to electrical stimulation in small networks (5-30 cells) and acute hippocampal slices.
• Generalized the depression-facilitation model to extract network time constants.
• Analyzed the relationship between synaptic density and reverberation time.

Main Results:

• A single electrical stimulus elicited synchronous, long-lasting bursting activity in both small and large networks.
• Reverberating activity lasted 2-5 seconds in small networks but only up to 300 milliseconds in hippocampal slices.
• The generalized model predicted a bell-shaped relationship between reverberation time and synaptic density, with a maximum achievable bursting duration.

Conclusions:

• Synaptic dynamics and network connectivity are key determinants of mean burst duration across different network scales.
• Sufficient network connectivity is essential for bursting reverberation.
• Collective synaptic depression and facilitation underlie the generation of bursting reverberation in neural networks.