Inter-Animal Variability in Activity Phase Is Constrained by Synaptic Dynamics in an Oscillatory Network.

Area of Science:

• Neuroscience
• Computational Neuroscience
• Systems Neuroscience

Background:

• Neuronal voltage-gated and synaptic currents vary significantly between individuals.
• Despite current variability, phase relationships in oscillatory neural circuits remain stable, even with changing frequencies.

Purpose of the Study:

• To investigate if synaptic and intrinsic currents are coordinated to maintain constant activity phases across different preparations.
• To identify which specific current parameters are critical for maintaining phase relationships in neural oscillations.

Main Methods:

• Utilized the lateral pyloric (LP) neuron from the stomatogastric ganglion (STG) of *Cancer borealis* for experiments.
• Quantified synaptic current input parameters and voltage-gated currents across preparations.
• Employed dynamic clamp to apply artificial synaptic inputs and assess their influence on burst onset phase.

Main Results:

• No linear correlation was found between synaptic and voltage-gated current parameters.
• Synaptic parameters correlated with oscillation period and burst onset phase did not effectively influence burst onset.
• Parameters with minimal variability across preparations demonstrated the most significant influence on burst onset.

Conclusions:

• Specific synaptic parameters crucial for circuit phasing are tightly regulated across individuals.
• Parameters with little effect on phasing exhibit co-variation with oscillation phase and frequency.
• Neural circuit timing is robust due to constrained intrinsic properties rather than variable synaptic inputs.