An inhibitory acetylcholine receptor gates context-dependent mechanosensory processing in C. elegans

Area of Science:

• Neuroscience
• Animal Behavior
• Molecular Biology

Background:

• An animal's behavior influences its response to sensory stimuli, but the underlying molecular and circuit mechanisms are not fully understood.
• In the nematode C. elegans, turning behavior reduces the likelihood of responding to mechanosensory stimuli, indicating a gating mechanism.
• Inhibitory feedback from turning neurons is known to be involved, but the precise location and molecular players remain elusive.

Purpose of the Study:

• To identify the specific neuron and receptor responsible for gating mechanosensory responses during turning in C. elegans.
• To elucidate the molecular and circuit-level mechanisms of context-dependent decision-making in sensorimotor processing.

Main Methods:

• Genetic manipulations in C. elegans.
• Single-cell rescue experiments.
• High-throughput closed-loop optogenetic perturbations during behavior.

Main Results:

• The inhibitory acetylcholine-gated chloride channel, composed of LGC-47 and ACC-1 subunits, expressed in RIM neurons, was identified as the key player.
• This channel disrupts mechanosensory-evoked reversals specifically during turning behavior.
• This disruption is likely due to inhibitory signals from the turning-associated neuron SAA.

Conclusions:

• The study pinpoints RIM neurons and the LGC-47/ACC-1 chloride channel as the specific site and molecular component mediating sensory gating during turning in C. elegans.
• This finding advances our understanding of how neural circuits integrate behavioral context to modulate sensory processing and decision-making.