C. elegans multi-dendritic sensory neurons: morphology and function.

Area of Science:

• Neuroscience
• Mechanosensation
• C. elegans biology

Background:

• The nematode C. elegans possesses PVD and FLP neurons, which form extensive, branched networks across the adult body.
• These neurons function as mechanosensors, with PVD specifically mediating responses to high-threshold mechanical stimuli, analogous to mammalian nociceptors.

Purpose of the Study:

• To investigate the functional roles of PVD and FLP sensory neurons in C. elegans behavior.
• To elucidate the contribution of these neurons to mechanosensation, movement regulation, proprioception, and defensive behaviors.

Main Methods:

• Generation of C. elegans strains lacking PVD and FLP neurons.
• Behavioral analysis to assess movement, dwelling, posture, and egg-laying responses.
• Calcium imaging in PVD neurons to monitor activity during movement.
• Genetic analysis involving the MEC-10 mechanosensory channel subunit.

Main Results:

• Absence of PVD and FLP neurons leads to increased dwelling behavior and defective posture, suggesting roles in movement regulation and proprioception.
• PVD neurons exhibit movement-dependent calcium transients requiring the MEC-10 channel subunit, which is also crucial for maintaining wild-type posture.
• Strong mechanical stimulation inhibits egg-laying, a response dependent on PVD and FLP neurons.

Conclusions:

• PVD and FLP neurons integrate both noxious and innocuous mechanical signals to control C. elegans behavior.
• These neurons combine functions of multiple mammalian somatosensory neuron types, including nociceptors and proprioceptors.
• Noxious stimuli detected by PVD and FLP neurons trigger an escape response characterized by increased speed, reduced pauses, and suppressed egg-laying.