The Volatile Halogenated Anesthetic Sevoflurane Inhibits Microtubule-Generated Electrical Oscillations In The Honeybee Brain

GUTIERREZ BC; CANTIELLO HF; CANTERO MR

MAR DEL PLATA

Congreso; Reunión Anual de Sociedades de Biociencias SAI SAIC SAFIS; 2022

SAFIS SAIC SAI FAIC

Microtubules (MTs) are highly conserved cytoskeleton structures associated with information transfer within neuronal processes. Recent electrophysiological studies demonstrated that different assemblies of brain MTs generate highly synchronous electrical oscillations (Cantero et al. Sci Rep 2016, 2018). To further explore the MT electrical activity of the brain, we applied the patch clamp technique on MT sheets and brains obtained from the honeybee (Apis mellifera), as recently reported (Gutierrez et al. Front Mol Neurosci 2021). High resistance seal patches of MT sheets showed electrical oscillations that linearly depended on the holding potential between ±200 mV and had an average conductance of 9.2 ± 0.3 nS (n = 14). To observe these oscillations in the context of the brain, we further explored local field potentials (LFP) in the Triton X-permeabilized whole honeybee brain, unmasking spontaneous oscillations after but not before tissue permeabilization. In both preparations, the frequency domain spectral analysis of time records indicated at least two fundamental peaks at ~38 Hz and ~93 Hz. To evaluate the effect of halogenated ether anesthetics on the electrical properties of MTs, we tested the inhalational anesthetic sevoflurane used in the clinic. The addition of sevoflurane (12.5% v/v) had an inhibitory effect on high seal patches of bee brain MT sheets, reducing electrical oscillations by 69.4 ± 16.1% (n = 7). Whole brain electrical oscillations were also reversibly inhibited by the addition of sevoflurane (n = 3). The present data indicate that the electrical activity of MTs provides a novel signaling mechanism in the honeybee brain that targets volatile anesthetics and may be implicated in the brainwave oscillations observed in the insect brain.