PMID- 36244004 OWN - NLM STAT- MEDLINE DCOM- 20221128 LR - 20221212 IS - 1432-0770 (Electronic) IS - 0340-1200 (Print) IS - 0340-1200 (Linking) VI - 116 IP - 5-6 DP - 2022 Dec TI - A dynamic spike threshold with correlated noise predicts observed patterns of negative interval correlations in neuronal spike trains. PG - 611-633 LID - 10.1007/s00422-022-00946-5 [doi] AB - Negative correlations in the sequential evolution of interspike intervals (ISIs) are a signature of memory in neuronal spike-trains. They provide coding benefits including firing-rate stabilization, improved detectability of weak sensory signals, and enhanced transmission of information by improving signal-to-noise ratio. Primary electrosensory afferent spike-trains in weakly electric fish fall into two categories based on the pattern of ISI correlations: non-bursting units have negative correlations which remain negative but decay to zero with increasing lags (Type I ISI correlations), and bursting units have oscillatory (alternating sign) correlation which damp to zero with increasing lags (Type II ISI correlations). Here, we predict and match observed ISI correlations in these afferents using a stochastic dynamic threshold model. We determine the ISI correlation function as a function of an arbitrary discrete noise correlation function [Formula: see text], where k is a multiple of the mean ISI. The function permits forward and inverse calculations of the correlation function. Both types of correlation functions can be generated by adding colored noise to the spike threshold with Type I correlations generated with slow noise and Type II correlations generated with fast noise. A first-order autoregressive (AR) process with a single parameter is sufficient to predict and accurately match both types of afferent ISI correlation functions, with the type being determined by the sign of the AR parameter. The predicted and experimentally observed correlations are in geometric progression. The theory predicts that the limiting sum of ISI correlations is [Formula: see text] yielding a perfect DC-block in the power spectrum of the spike train. Observed ISI correlations from afferents have a limiting sum that is slightly larger at [Formula: see text] ([Formula: see text]). We conclude that the underlying process for generating ISIs may be a simple combination of low-order AR and moving average processes and discuss the results from the perspective of optimal coding. CI - (c) 2022. The Author(s). FAU - Sidhu, Robin S AU - Sidhu RS AD - Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA. FAU - Johnson, Erik C AU - Johnson EC AD - The Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA. FAU - Jones, Douglas L AU - Jones DL AD - Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA. FAU - Ratnam, Rama AU - Ratnam R AUID- ORCID: 0000-0002-9931-7846 AD - Division of Biological and Life Sciences, School of Arts and Sciences, Ahmedabad University, Ahmedabad, Gujarat, India. rama.ratnam@ahduni.edu.in. LA - eng GR - EFRI-BSBA-0938007/National Science Foundation/ GR - IGERT 0903622/National Science Foundation/ PT - Journal Article PT - Research Support, N.I.H., Extramural PT - Research Support, Non-U.S. Gov't PT - Research Support, U.S. Gov't, Non-P.H.S. DEP - 20221016 PL - Germany TA - Biol Cybern JT - Biological cybernetics JID - 7502533 SB - IM MH - Animals MH - Action Potentials/physiology MH - *Electric Fish/physiology MH - Neurons/physiology MH - Noise MH - Models, Neurological PMC - PMC9691502 OTO - NOTNLM OT - Adaptation OT - Dynamic threshold OT - Negative interspike interval correlations OT - Noisy threshold OT - Optimal neural coding OT - P-type electrosensory afferents OT - Serial correlation coefficients OT - Weakly electric fish EDAT- 2022/10/17 06:00 MHDA- 2022/11/29 06:00 PMCR- 2022/10/16 CRDT- 2022/10/16 13:59 PHST- 2021/12/10 00:00 [received] PHST- 2022/09/26 00:00 [accepted] PHST- 2022/10/17 06:00 [pubmed] PHST- 2022/11/29 06:00 [medline] PHST- 2022/10/16 13:59 [entrez] PHST- 2022/10/16 00:00 [pmc-release] AID - 10.1007/s00422-022-00946-5 [pii] AID - 946 [pii] AID - 10.1007/s00422-022-00946-5 [doi] PST - ppublish SO - Biol Cybern. 2022 Dec;116(5-6):611-633. doi: 10.1007/s00422-022-00946-5. Epub 2022 Oct 16.