A matched-filter algorithm to detect amperometric spikes resulting from quantal secretion

作者：Ramachandran Supriya Balaji; Gillis Kevin D^*

来源：Journal of Neuroscience Methods, 2018, 293: 338-346.

DOI：10.1016/j.jneumeth.2017.10.019

• Quantal exocytosis
• Spike detection
• Signal processing
• Carbon-fiber amperometry

Background: Electrochemical microelectrodes located immediately adjacent to the cell surface can detect spikes of amperometric current during exocytosis as the transmitter released from a single vesicle is oxidized on the electrode surface. Automated techniques to detect spikes are needed in order to quantify the spike rate as a measure of the rate of exocytosis.
New method: We have developed a Matched Filter (MF) detection algorithm that scans the data set with a library of prototype spike templates while performing a least-squares fit to determine the amplitude and standard error. The ratio of the fit amplitude to the standard error constitutes a criterion score that is assigned for each time point and for each template. A spike is detected when the criterion score exceeds a threshold and the highest-scoring template and the time of peak score is identified. The search for the next spike commences only after the score falls below a second, lower threshold to reduce false positives. The approach was extended to detect spikes with double-exponential decays with the sum of two templates.
Results: Receiver Operating Characteristic plots (ROCS) demonstrate that the algorithm detects >95% of manually identified spikes with a false-positive rate of 2%.
Comparison with existing methods: ROCs demonstrate that the MF algorithm performs better than algorithms that detect spikes based on a derivative-threshold approach.
Conclusions: The MF approach performs well and leads into approaches to identify spike parameters.

• 出版日期2018-1-1