Relative wavelet energy as a measure of the magnetic fields effects on the neuronal population activity in Morimus funereus (Coleoptera, Cerambycidae) antennal lobe

Abstract

Based on a wavelet analysis, this study introduces the relative wavelet energy (RWE) as a new measure for classification of the frequency bands of neuronal population activity in insects. The RWE is used to explore the effects of static magnetic field (SMF, 2 mT) and extremely low frequency magnetic field (ELF MF, 50 Hz, 2 mT) on longhorn beetle antennal lobe neuronal activity. To study the influence of SMF and ELF MF on the neuronal population activity, the experiments were performed on adult longhorn beetles Morimus funereus (Coleoptera, Cerambycidae). Our study, based on a wavelet analysis of the local field potentials (LFPs), showed for the first time that the effects of prolonged and repeated exposure to the ELF MF on the LFPs were irreversible. Compared to the control, the RWE of 4-8 Hz frequency band was increased after repeatedly applied sine ELF MF (SnMF)/square ELF MF (SqMF). On the other hand, the RWE of slower oscillations (1-2 Hz) was significantly decreased after repeated exposures to both applied ELF MF waveforms. The SqMF decreased the fastest 64-128 Hz frequency band. However, exposure to the SMF didn't have any effects on the neuronal population activity. This study, successfully demonstrated new and useful application of the RWE method for classification of the frequency bands and measuring the effects of SMF and ELF MF on the neuronal population activity in M. funereus antennal lobe.