Lateral facilitation between primary mechanosensory neurons controls nose touch perception in C. elegans

Area of Science:

• Neuroscience
• Mechanobiology
• Sensory Biology

Background:

• The nematode Caenorhabditis elegans utilizes various mechanoreceptor neurons for sensing touch.
• These neurons are interconnected via a network of gap junctions, facilitating electrical coupling.

Purpose of the Study:

• To investigate the role of gap junctions in C. elegans mechanosensation.
• To elucidate the mechanisms underlying the differential response to gentle versus harsh touch stimuli.
• To understand the bidirectional information flow within the mechanosensory network.

Main Methods:

• In vivo neuroimaging techniques were employed to observe neuronal activity.
• Electrophysiological properties and network connectivity were analyzed.
• Behavioral responses to varying touch stimuli were correlated with neural activity.

Main Results:

• Multidendritic nociceptors in C. elegans respond to harsh touch across their receptive field.
• Gentle nose touch elicits responses only at the nose tip, requiring facilitation from other mechanoreceptors.
• A hub-and-spoke gap junction network enables electrical coupling between nociceptors and nose touch mechanoreceptors.
• Bidirectional information flow was observed, where nociceptor activity influences nose touch neuron activation.

Conclusions:

• A simple gap junction circuit functions as a coincidence detector in C. elegans.
• This network integrates information from neighboring mechanoreceptors for somatosensory perception.
• The findings reveal a sophisticated mechanism for distinguishing touch intensity and location.