インビボ体細胞および内臓刺激に対する背根神経節ニューロンの応答のカルシウムイメージング

Overview

This study presents a detailed protocol for in vivo calcium imaging to assess the responses of lumbar-6 dorsal root ganglion (DRG) neurons to somatic and visceral stimuli. The method allows for comparative analysis of neuronal responses to various stimuli, enhancing our understanding of visceral pain mechanisms and the effects of somatic interventions, such as acupuncture.

Key Study Components

Area of Science

• Neuroscience
• Pain Research
• Neuroimaging

Background

• Traditional electro recording methods are insufficient for examining sufficient cell numbers in vivo.
• The study addresses the challenges in observing the functional roles of DRG neurons in visceral pain contexts.
• The approach improves upon previous techniques that primarily focused on L5 DRG neurons.
• Technological advancements enable detailed observation of acetylcholine responses related to acupuncture and visceral stimuli.

Purpose of Study

• To investigate the responsiveness of lumbar-6 DRG neurons to somatic and visceral stimuli.
• To elucidate the mechanisms underlying the analgesic effects of acupuncture.
• To develop a reliable protocol for in vivo imaging of DRG neuron activity.

Methods Used

• Calcium imaging of in vivo preparations, specifically lumbar-6 DRG neurons.
• The model involves tracheostomized mice, which are subjected to surgical exposure of the lumbar DRG.
• Real-time imaging captures neuronal responses to somatic and visceral stimuli.
• Procedures include electrode placement, stimulation methods, and imaging techniques with confocal microscopy.
• Timelapse imaging captures calcium signaling responses to various stimuli.

Main Results

• Colorectal distension and electroacupuncture led to rapid increases in GCaMP fluorescence, indicating neuronal activation.
• Responses were quantitatively assessed through fluorescence intensity, revealing important insight into neuronal excitability changes.
• Heat maps demonstrated the differential responses of neurons to somatic versus visceral stimuli.
• Findings inform on the cellular dynamics involved in visceral nociception.

Conclusions

• This study confirms the protocol's utility in exploring neuronal responses to acupuncture and visceral pain stimuli.
• The imaging method provides a powerful tool for future research on the mechanisms of pain and acupuncture.
• The findings enhance understanding of nociceptive signaling, potentially influencing therapeutic strategies for pain management.

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