Basomedial amygdala activity in mice reflects specific and general aversion uncontrollability

Area of Science:

• Neuroscience
• Behavioral Neuroscience
• Stress Research

Background:

• Adaptive behavior relies on learning to control aversive stimuli.
• Chronic exposure to uncontrollable aversive situations can lead to maladaptive changes in neural processing.
• The basomedial amygdala (BMA) is implicated in aversion processing, with higher activity linked to active behavioral responses.

Purpose of the Study:

• To investigate the relationship between aversion (un)controllability, BMA neural activity, and behavioral outcomes in mice.
• To differentiate the neural correlates of acute versus chronic uncontrollable aversion.
• To determine if BMA activity can serve as a neural marker for adaptive and maladaptive states.

Main Methods:

• Utilized fiber photometry with GCaMP6 to monitor BMA neuron activity in freely behaving mice.
• Exposed mice to mild electrical shocks under conditions of escapable shock (ES) and inescapable shock (IES).
• Implemented a learned helplessness paradigm and chronic social stress (CSS) model to investigate specific and general (un)controllability.

Main Results:

• Mice exposed to inescapable shock (IES) showed fewer escape attempts and higher BMA activity compared to escapable shock (ES) mice.
• Following chronic social stress (CSS), mice exhibited reduced escape behavior and decreased BMA activity compared to control (CON) mice.
• BMA activity patterns shifted, being elevated during acute uncontrollable aversion but reduced after chronic uncontrollable aversion exposure.

Conclusions:

• Mouse BMA activity is dynamically modulated by the controllability of aversive experiences.
• Elevated BMA activity may reflect an adaptive response to immediate uncontrollable aversion.
• Reduced BMA activity following chronic uncontrollable aversion suggests a potential neural marker for maladaptive stress responses.