Simulation of hippocampal afterdischarges synchronized by electrical interactions

Area of Science:

• Neuroscience
• Computational Neuroscience

Background:

• Recent experiments demonstrate hippocampal pyramidal cells can synchronize action potentials without chemical synapses.
• The underlying mechanism for this synchrony remains an area of investigation.

Purpose of the Study:

• To investigate the role of extracellular currents in neuronal synchrony.
• To identify conditions necessary for synchrony mediated by extracellular communication.

Main Methods:

• Computer simulations of hippocampal pyramidal cells.
• Modeling of extracellular current flow between neurons.
• Varying neuronal excitability and extracellular resistivity parameters.

Main Results:

• Extracellular currents can induce synchronized action potentials in simulated hippocampal pyramidal cells.
• High neuronal excitability and high extracellular resistivity are critical for this synchrony.
• The presence of electronic junctions further enhances neuronal synchronization.

Conclusions:

• Extracellular current-mediated communication is a viable mechanism for neuronal synchrony in the hippocampus.
• Neuronal and environmental properties significantly influence the efficacy of this communication pathway.