Beyond spikes: Multiscale computational analysis ofin vivolong-term recordings in the cockroach circadian clock

Abstract

The circadian clock of the nocturnal Madeira cockroach is located in the accessory medulla, a small nonretinotopic neuropil in the brain’s visual system. The clock comprises about 240 neurons that control rhythms in physiology and behavior such as sleep-wake cycles. The clock neurons contain an abundant number of partly colocalized neuropeptides, among them pigment-dispersing factor (PDF), the insects’ most important circadian coupling signal that controls sleep-wake rhythms. We performed long-term loose-patch clamp recordings under 12:12-hr light-dark cycles in the cockroach clock in vivo. A wide range of timescales, from milliseconds to seconds, were found in spike and field potential patterns. We developed a framework of wavelet transform–based methods to detect these multiscale electrical events. We analyzed frequencies and patterns of events with interesting dynamic features, such as mixed-mode oscillations reminiscent of sharp-wave ripples. Oscillations in the beta/gamma frequency range (20–40 Hz) were observed to rise at dawn, when PDF is released, peaking just before the onset of locomotor activity of the nocturnal cockroach. We expect that in vivo electrophysiological recordings combined with neuropeptide/antagonist applications and behavioral analysis will determine whether specific patterns of electrical activity recorded in the network of the cockroach circadian clock are causally related to neuropeptide-dependent control of behavior.

The lateral posterior clock neurons of Drosophila melanogaster express three neuropeptides and have multiple connections within the circadian clock network and beyond

“…Animals possess a circadian master clock in the brain that modulates their daily behavior and coordinates the clocks in the body. This master clock consists of a network of interacting neurons that are characterized by different morphology, neurochemistry, and physiology and may fulfill different roles in the clock (Herzog et al., 2017; Michel & Meijer, 2020; Mieda, 2020; Rojas et al., 2019; Stengl & Arendt, 2016). The fruit fly, Drosophila melanogaster , is an attractive model for studying this clock network in detail because it is composed of only 150 neurons many of which are already largely characterized (reviewed by Beckwith & Ceriani, 2015; Helfrich‐Förster, 2017; King & Sehgal, 2020; Top & Young, 2018).…”

The Neuronal Circuit of the Dorsal Circadian Clock Neurons in Drosophila melanogaster

“…In animals, a master clock is located in the brain that tunes physiology, metabolism, and behavior to their respective temporal niche. In mammals and insects, this circadian master clock consists of tightly interacting neurons that may fulfill different roles in the clock network based on their neurochemistry, morphology and physiology (Beckwith and Ceriani, 2015;Stengl and Arendt, 2016;Helfrich-Förster, 2017;Herzog et al, 2017;Top and Young, 2018;Rojas et al, 2019;King and Sehgal, 2020;Michel and Meijer, 2020;Mieda, 2020;Ahmad et al, 2021).…”

Optimal time frequency analysis for biological data - pyBOAT

“…Continuous wavelet analysis allows to reveal non-stationary period, amplitude and phase dynamics and to identify multiple frequency components across dierent scales within a single oscillatory signal (Leise [2013], Leise et al [2012], Rojas et al [2019]) and is thus complementary to approaches that are designed to analyze stationary data. In contrast to the R-based waveclock package (Price et al [2008]), pyBOAT can be operated as a standalone software tool that requires no prior programming knowledge as it can be fully operated using its graphical user interface (GUI).…”