Computational solution of spike overlapping using data-based subtraction algorithms to resolve synchronous...

Area of Science:

• Neuroscience
• Computational Biology
• Physiology

Background:

• Sympathetic nerves regulate visceral functions through synchronous firing patterns.
• Simultaneous recording of multiple nerve fibers (oligofiber recording) is crucial for understanding synchronous activity.
• Overlapping spike potentials in synchronous discharges create complex waveforms, hindering analysis.

Purpose of the Study:

• To develop and validate novel computational methods for accurately analyzing synchronous nerve fiber activity.
• To address limitations of commercial software in resolving complex waveforms from overlapping spikes.
• To enable precise quantification of individual fiber firing within synchronous bursts.

Main Methods:

• Utilized in vitro splanchnic sympathetic nerve-thoracic spinal cord preparations from neonatal rats.
• Developed custom LabVIEW programs and MATLAB scripts for spike sorting and analysis.
• Employed k-means clustering, principal component analysis (PCA), and a data-based subtraction algorithm (SA) for waveform analysis.
• Integrated T(2)-selected and SA-retrieved spikes to define unit activities.

Main Results:

• The custom algorithms demonstrated higher accuracy than commercial software in analyzing synthetic data with synchronous spiking and complex waveforms.
• The subtraction algorithm effectively identified and resolved complex waveforms resulting from spike overlapping.
• Combined unit activities (T(2)-selected and SA-retrieved spikes) allowed for quantitative evaluation of single-fiber origin.
• The developed methods successfully resolved synchronous sympathetic nerve discharges (SND).

Conclusions:

• The novel computational approach effectively resolves complex waveforms arising from synchronous nerve fiber activity.
• This methodology provides a more accurate means to analyze and quantify individual fiber firing within synchronous bursts.
• The developed programs offer a valuable tool for researchers studying sympathetic nerve discharges and visceral function regulation.