Functional Connectomes in Time Domain from Simulated Neurotransmitter Release Based on Electrocorticograms

Area of Science:

• Neuroscience
• Computational Neuroscience
• Signal Processing

Background:

• Distinguishing conditioned from unconditioned stimuli is crucial for understanding neural processing.
• Electrocorticogram (ECoG) signals offer insights into brain activity.
• Simulated neurotransmitter release (NTR) provides a novel metric for neural activity.

Purpose of the Study:

• To define a functional connectome using NTR from ECoG data.
• To differentiate between conditioned and unconditioned stimuli based on connectome values.
• To investigate the neural mechanisms underlying stimulus association and habituation in the visual cortex.

Main Methods:

• Calculation of connectome values in the time domain of simulated NTR from ECoG.
• Analysis of 64-channel NTR trains within the 8-20 Hz frequency band.
• Comparison of connectome indexes between conditioned (association) and unconditioned (habituation) stimuli in rabbit visual cortices.

Main Results:

• A newly defined functional connectome effectively distinguishes conditioned from unconditioned stimuli.
• Connectome indexes were significantly larger for association compared to habituation in the small-scale visual cortex.
• Increased trial-to-trial variability in large-scale synchrony after conditional stimulation was observed, consistent with attention-related decreases in low-frequency coherence.

Conclusions:

• The functional connectome derived from NTR is a sensitive indicator of stimulus-specific neural responses.
• Associated stimuli evoke stronger responses in the small-scale visual cortex than habituation, even amidst background cortical states and attention effects.
• This approach enhances the understanding of how the brain processes and differentiates stimuli through neurotransmitter dynamics and functional connectivity.