Functional imaging in microfluidic chambers reveals sensory neuron sensitivity is differentially regulated between...

Area of Science:

• Neuroscience
• Cell Biology
• Physiology

Background:

• Primary afferent sensory neurons are long cells crucial for transmitting sensory information.
• Current in vitro models often fail to capture the entire neuron, focusing on cell bodies and neglecting peripheral functions.
• Accurate modeling is essential for understanding sensory neuron physiology and ion channel function.

Purpose of the Study:

• To develop and validate a method for accurately modeling primary afferent sensory neurons in vitro.
• To compare the functional protein expression and sensitivity of different neuronal regions, specifically terminals and somata.
• To investigate the differential regulation of excitability and sensitivity in sensory neurons.

Main Methods:

• Utilized compartmentalized sensory neuron cultures within microfluidic chambers.
• Employed ratiometric calcium imaging to assess neuronal activity and sensitivity.
• Investigated action potential propagation, tetrodotoxin sensitivity, proton sensitivity, and capsaicin sensitivity.

Main Results:

• Demonstrated that microfluidic chambers allow for accurate comparison of sensitivity and protein expression between isolated neuronal regions.
• Showcased action potential propagation in nerve terminals with both tetrodotoxin-resistant and -sensitive components.
• Revealed differential regulation of proton sensitivity between sensory terminals and somata, and age-dependent capsaicin sensitivity.

Conclusions:

• Ratiometric calcium imaging in compartmentalized cultures provides a comprehensive method to study sensory neuron excitability and regional sensitivity.
• The findings highlight crucial differences between sensory terminals and somata, emphasizing the importance of studying nerve endings.
• This approach is vital for advancing the understanding of dorsal root ganglion neuron properties and diversity.