Simultaneous whole-cell patch-clamp and calcium imaging on myenteric neurons.

Area of Science:

• Neuroscience
• Cellular Physiology
• Enteric Nervous System Research

Background:

• Live calcium imaging is a key tool for studying neuronal activity in the enteric nervous system (ENS).
• Enteric neurons are broadly classified into after-hyperpolarizing (AH) and synaptic (S)-neurons, with distinct calcium handling properties.
• Previous research suggested S-neurons require multiple action potentials for calcium transients, complicating imaging data interpretation.

Purpose of the Study:

• To investigate how enteric neurons respond to different depolarization modes using simultaneous electrophysiology and calcium imaging.
• To clarify the relationship between action potentials and calcium transients in AH- and S-neurons.
• To identify imaging-based methods for distinguishing between AH- and S-neuron subtypes.

Main Methods:

• Simultaneous whole-cell patch-clamp electrophysiology and live calcium imaging in mouse myenteric neurons.
• Application of traditional (4 Hz) and high-speed (1,000 Hz) imaging techniques.
• Stimulation via controlled depolarization and nicotinic acetylcholine receptor activation.

Main Results:

• Single action potentials elicit calcium transients in both AH- and S-neurons.
• Subthreshold depolarizations also induce calcium transients, amplified by action potentials.
• Nicotinic acetylcholine receptor stimulation effectively distinguishes between AH- and S-neurons in calcium imaging.

Conclusions:

• Contrary to previous assumptions, single action potentials evoke calcium transients in both AH- and S-enteric neurons.
• Calcium imaging can accurately reflect neuronal activity in both major enteric neuron classes.
• Targeted receptor stimulation offers a novel method for classifying enteric neuron subtypes in live imaging studies.