Focused Ultrasound Evoked Responses in Dorsal Root Ganglion Neurons (DRG) and HEK293 Cells

Abstract

total dimensions of 600 Â 600 Â 100 mm. Pillars of different height with cavities on top, which act as attachment sites for the somata of the neurons, are connected to each other through channels to guide the neurites from one pillar to the next in a precise predefined way. The inner diameter of the channels, 3.6 mm, is tailored to fit the axon-diameter of 2-3 mm. To specifically enhance cell attachment, poly-D-lysin is printed directly into the cavities of the pillars. The substrate is cultured with granule cells from murine cerebella. Cell activity after at least 5 days in vitro is shown through basic patch-clamp measurements. The work presented here is a prove of principle for an approach to build complex, tailor-made 3D neural circuits.

A Review on Ultrasonic Neuromodulation of the Peripheral Nervous System: Enhanced or Suppressed Activities?

“…In addition, interpretation of the results from in vivo studies can be confounded by indirect effects of US on surrounding muscles, blood vessels and immune cells. In vitro cultures of dissociated sensory neurons from the dorsal root ganglion (DRG) have also been used as a model to study the effects of US neuromodulation ( 67 ). Although the sensory cell somata in the DRG differ significantly from the nerve axons and endings in fundamental electrophysiological properties ( 57 ), the neurite outgrowth in cultured DRG has similar dimensions as axons and nerve endings and thus could potentially be an adequate model for studying peripheral neuromodulation.…”

“…To the best of our knowledge, all existing DRG neuromodulations implement electrical stimulation, and the modality of US has yet to be investigated on DRG. A recent pilot report with patch-clamp and calcium imaging recordings on dissociated DRG neurons showed that US evokes action potentials in 33–40% DRG neurons, which may involve the activation of sodium, calcium and non-selective ion channels ( 67 ).…”

“…Virtually no study has been conducted to assess the US neuromodulation on intact DRG, the clustering of sensory afferent somata. A recent study indicates that action potentials can be evoked by focused US in dissociated DRG neurons ( 67 ), opening new avenues of research on US DRG neuromodulation in future preclinical and clinical studies. The underlying mechanisms of US activation of DRG neurons are unclear, which likely involve sodium, potassium and non-selective cation channels ( 67 ).…”