Experience-dependent information routing through the basolateral amygdala shapes behavioral outcomes.

Area of Science:

• Neuroscience
• Behavioral Science
• Psychology

Background:

• The basolateral amygdala (BLA) is a key brain region for emotional processing and behavioral control.
• The BLA contains diverse neuronal populations that are selectively activated to produce varied behavioral outputs.
• The influence of prior experiences on BLA neuronal activity and subsequent behaviors is not well understood.

Purpose of the Study:

• To investigate how distinct prior experiences, specifically enriched environment (EE) and chronic unpredictable stress (CUS), affect BLA neuronal activity.
• To determine if these experiences differentially impact BLA principal neurons projecting to different downstream targets.
• To explore the causal role of these projection-specific BLA neurons in mediating behavioral responses to stress and environmental enrichment.

Main Methods:

• Utilized chemogenetics to selectively manipulate projection-specific BLA neurons in rodent models.
• Compared the effects of prior enriched environment (EE) and chronic unpredictable stress (CUS) exposures.
• Assessed behavioral outcomes, including avoidance behaviors and stress-induced helplessness.

Main Results:

• Previous EE or CUS experiences differentially altered the activity of BLA principal neurons projecting to the nucleus accumbens core or bed nucleus of the stria terminalis.
• Chemogenetic manipulation of these projection-specific neurons could replicate or block the behavioral effects of EE and CUS.
• Bidirectional control over avoidance behaviors and stress-induced helplessness was achieved by targeting these neuronal populations.

Conclusions:

• Prior life experiences significantly modulate the functional activity of projection-specific BLA principal neurons.
• This experience-dependent plasticity in the BLA biases information flow through distinct circuits.
• Altered information routing within the BLA, driven by past experiences, underlies divergent behavioral outcomes in emotional contexts.