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INSTITUTO MULTIDISCIPLINARIO DE SALUD, TECNOLOGIA Y DESARROLLO
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Brain Microtubule Structures Behave as Memristive Devices
Autor/es:
CANTERO MR; GUTIERREZ BC; PEREZ PL; CANTIELLO HF; SCARINCI N
Reunión:
Congreso; Biophysical Society Annual Meeting; 2020
Resumen:
Microtubules (MTs) are cytoskeletal structures that play a central role in a variety of cell functions including cell division and cargo transfer. MTs are also nonlinear electrical transmission lines that produce and conduct electrical oscillations elicited by changes in either electric field and/or ionic gradients. The oscillatory behavior of MT structures requires a voltage-sensitive gating mechanism to enable the electrodiffusional ionic movement through the MT wall. To ascertain the nature of the possible gating mechanism, here we explored the electrical response of non-oscillating rat (n = 118) and bee (n = 19) brain MT sheets to square voltage steps. Giga-seal samples were voltage-clamped under symmetrical 140 mM KCl conditions. On-Off transient current responses were obtained and analyzed against an RC electrical model. Data were inconsistent with a capacitive relaxation response and capacitive charge transfer. A complex voltage-dependent nonlinear charge movement was observed instead, which represented the summation of two events. The first contribution was a small, saturating, voltage-dependent capacitance with a maximum charge displacement in the range of 4 fC/microm 2. A second, major contribution was a non-saturating voltage-dependent charge transfer consistent with the properties of a multistep memristive device. The memristive model of the non-oscillating MT sheets was consistent with a hybrid of current memristor devices, showing an I-V pinched hysteretic loop, and an extremely large memristive ratio (>1300), consistent with a memristive switch capable of sustaining electrical oscillations. The memristive capabilities of MTs could enable voltage-driven neuromorphic circuits and architectures within neurons.