Investigating the Function of Adult DRG Neuron Axons Using an In Vitro Microfluidic Culture System.

Rahul Atmaramani,Srivennela Veeramachaneni,Pratik Koppikar,Rafael Granja-Vazquez,Audrey Hammack,Joseph J Pancrazio,Liz Valeria Mogas,Bryan J Black

doi:10.3390/mi12111317

Rahul Atmaramani, Srivennela Veeramachaneni + Show 6 more

Open Access

https://doi.org/10.3390/mi12111317

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Journal: Micromachines	Publication Date: Oct 27, 2021
Citations: 7	License type: CC BY 4.0

Affiliation: The University of Texas at Dallas

Abstract

A critical role of the peripheral axons of nociceptors of the dorsal root ganglion (DRG) is the conduction of all-or-nothing action potentials from peripheral nerve endings to the central nervous system for the perception of noxious stimuli. Plasticity along multiple sites along the pain axis has now been widely implicated in the maladaptive changes that occur in pathological pain states such as neuropathic and inflammatory pain. Notably, increasing evidence suggests that nociceptive axons actively participate through the local expression of ion channels, receptors, and signal transduction molecules through axonal mRNA translation machinery that is independent of the soma component. In this report, we explore the sensitization of sensory neurons through the treatment of compartmentalized axon-like structures spanning microchannels that have been treated with the cytokine IL-6 and, subsequently, capsaicin. These data demonstrate the utility of isolating DRG axon-like structures using microfluidic systems, laying the groundwork for constructing the complex in vitro models of cellular networks that are involved in pain signaling for targeted pharmacological and genetic perturbations.

Highlights

A critical role of the peripheral axons of nociceptors of the dorsal root ganglion (DRG)is excitation from peripheral nerve endings to the central nervous system for the perception of noxious stimuli [1]
DRG neurons were plated in the soma chamber (Figure 1D), and the axonal compartment was treated with a combination of nerve growth factor (NGF) and glial-derived neurotrophic factor (GDNF), and crossings were monitored over a 6-day period
A microfluidic-based system is shown for the culture and study of nociceptive axon-like structures in vitro from adult mouse DRG neurons

Summary

Introduction

A critical role of the peripheral axons of nociceptors of the dorsal root ganglion (DRG)is excitation from peripheral nerve endings to the central nervous system for the perception of noxious stimuli [1]. A critical role of the peripheral axons of nociceptors of the dorsal root ganglion (DRG). The peripheral terminals, not the soma, are exposed to a myriad of inflammatory cytokines and immune-related molecules during inflammation and/or nerve injury and may contribute to the peripheral hyperexcitability of mouse DRG neurons [5]. A more detailed understanding of the role of axons that are independent of the soma in nociceptive plasticity is required. The ability to physically and chemically isolate peripheral axons for genetic and or pharmacological manipulation may elucidate the role of axons in the maladaptive changes occurring in hyperexcitable nociceptors under inflammatory conditions. Typical in vitro neuronal cultures have no physical and chemical isolation of axonal processes, and principal measurements increasingly rely on that of cell soma responses.

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