THE VOLATILE HALOGENATED ANESTHETIC SEVOFLURANE INHIBITS MICROTUBULE-GENERATED ELECTRICAL OSCILLATIONS IN THE HONEYBEE BRAIN

GUTIERREZ BC; CANTIELLO HF; CANTERO MR

Congreso; Reunión Anual de Biociencias; 2022

Microtubules (MTs) are highly conserved cytoskeleton structures associated with informationtransfer within neuronal processes. Recent electrophysiological studies demonstrated thatdifferent 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). Highresistance seal patches of MT sheets showed electrical oscillations that linearly depended onthe 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 fieldpotentials (LFP) in the Triton X-permeabilized whole honeybee brain, unmaskingspontaneous oscillations after but not before tissue permeabilization. In both preparations, thefrequency domain spectral analysis of time records indicated at least two fundamental peaksat ~38 Hz and ~93 Hz. To evaluate the effect of halogenated ether anesthetics on the electricalproperties of MTs, we tested the inhalational anesthetic sevoflurane used in the clinic. Theaddition of sevoflurane (12.5% v/v) had an inhibitory effect on high seal patches of bee brainMT sheets, reducing electrical oscillations by 69.4 ± 16.1% (n = 7). Whole brain electricaloscillations were also reversibly inhibited by the addition of sevoflurane (n = 3). The presentdata indicate that the electrical activity of MTs provides a novel signaling mechanism in thehoneybee brain that targets volatile anesthetics and may be implicated in the brainwaveoscillations observed in the insect brain.