Repetitive noxious stimulus altered the shadow-induced withdrawal behavior in Lymnaea

Area of Science:

• Neuroscience
• Behavioral Biology
• Stress Research

Background:

• Stress significantly impacts adaptive behaviors, including vigilance.
• In Lymnaea, the shadow withdrawal response (SWR) is a key vigilance behavior mediated by dermal photoreceptors.
• The neural mechanisms underlying stress-induced behavioral changes require further investigation.

Purpose of the Study:

• To identify neural correlates of heightened SWR and other behaviors following traumatic stress in Lymnaea.
• To investigate electrophysiological changes in the RPeD11 interneuron after trauma.
• To determine the duration of stress-induced behavioral and neuronal alterations.

Main Methods:

• Electrophysiological properties of the RPeD11 interneuron were measured in traumatized and naive Lymnaea snails.
• Behavioral responses to shadow stimuli were assessed 24 hours and one week post-trauma.
• Locomotive, feeding, and respiratory behaviors were also monitored.

Main Results:

• Traumatized snails exhibited an augmented SWR and suppressed locomotive, feeding, and respiratory behaviors for at least one week.
• The RPeD11 interneuron in traumatized snails showed significant depolarization (∼10 mV) and increased input resistance.
• The duration of the RPeD11 response to shadow stimuli was prolonged in traumatized preparations.

Conclusions:

• Traumatic stress induces lasting behavioral and neuronal changes in Lymnaea, characterized by heightened SWR and altered RPeD11 function.
• The observed changes in RPeD11 contribute to an elevated defensive alert state in stressed snails.
• This study provides a neural basis for understanding stress-induced vigilance and behavioral suppression.