Ultrasonic control of neurite outgrowth direction

Abstract

This study investigated a method to control neurite outgrowth direction using ultrasound vibration. An ultrasound cell culture dish comprising a glass-bottom culture surface and a glass disc with an ultrasound transducer was fabricated, and undifferentiated neuron-like PC12 cells were grown on the dish as an adherent culture. The 78 kHz resonant concentric flexural vibration mode of the dish was used to quantitatively evaluate the neurite outgrowth direction and length. Time-lapse imaging of cells was performed for 72 h under ultrasound excitation. Unsonicated neurites grew in random directions, whereas neurite outgrowth was circumferentially oriented during ultrasonication in a power-dependent manner. The neurite orientation correlated with the spatial gradient of the ultrasound vibration, implying that neurites tend to grow in directions along which the vibrational amplitude does not change. Ultrasonication with 30 Vpp for 72 h increased the neurite length by 99.7% compared with that observed in unsonicated cells.

Physical Stimulation Methods Developed for In Vitro Neuronal Differentiation Studies of PC12 Cells: A Comprehensive Review

“…These studies also found that LIPUS activates the NGF-induced ERK1/2-CREB-Trx-1 pathway through stretch-activated ion channels to promote neurite outgrowth. In addition, Maruyama et al demonstrated that ultrasound stimulation under certain conditions increased NGF-induced neurite lengths and controlled the direction of neurite outgrowth [29]. Hoop et al reported the interesting observation that ultrasound stimulation leads to neurite outgrowth, but with piezoelectric stimulation using the piezoelectric polymer polyvinylidene fluoride (PVDF) instead of NGF [30].…”

Closing the Gap between the Auditory Nerve and Cochlear Implant Electrodes: Which Neurotrophin Cocktail Performs Best for Axonal Outgrowth and Is Electrical Stimulation Beneficial?

“…Our ES profiles could not trigger directional growth. Other approaches include light [101], fibrous scaffolds [95], ultrasound [102], or biochemical gradients [103], but they are limited by the complex and rather inaccessible structure of the cochlea. Our CI-like ES patterns could not boost or guide neurite outgrowth but decreased the number and length of neurites.…”

Microtubule Dynamics Following Central and Peripheral Nervous System Axotomy

“…It also controls the directionality of the growing tip of the neurite and promotes neuronal differentiation. 54 The interaction of myosin and actin is required for axon retraction. To achieve this, myosin II becomes activated and intra-axonal F-actin bundles are formed, resulting in the generation of a force driven by myosin II.…”

“…A study recently reported that ultrasonication significantly increases the length of neurites compared to those of unsonicated cells in a culture dish. It also controls the directionality of the growing tip of the neurite and promotes neuronal differentiation . The interaction of myosin and actin is required for axon retraction.…”