Intercalated Amygdala Dysfunction Drives Avoidance Extinction Deficits in the Sapap3 Mouse Model of...

Area of Science:

• Neuroscience
• Behavioral Science
• Computational Psychiatry

Background:

• Negative reinforcement learning is crucial for survival, involving dynamic responses to conflicting stimuli.
• Obsessive-compulsive disorder (OCD) is associated with impaired negative reinforcement and extinction, potentially due to amygdala dysfunction.
• The dorsal intercalated amygdala (ITC_d) is implicated in negative reinforcement and extinction.

Purpose of the Study:

• To investigate the role of the dorsal intercalated amygdala (ITC_d) in negative reinforcement and extinction.
• To examine ITC_d function during complex decision-making tasks modeling real-world scenarios.
• To explore the neural mechanisms underlying negative reinforcement deficits in an OCD mouse model.

Main Methods:

• Utilized a platform-mediated avoidance task in Sapap3-null mice, a model for OCD-like behavior.
• Employed fiber photometry with GCaMP6f to measure neural activity in the ITC_d.
• Applied optogenetic manipulations to modulate ITC_d function during the task.

Main Results:

• Sapap3-null mice displayed impaired neural activity in the ITC_d during negative stimulus encoding in the avoidance task.
• These mice showed deficits in extinguishing avoidant behavior, correlated with ITC_d neural activity.
• Heightened ITC_d activity was identified as the cause for the failure to extinguish avoidance behavior.

Conclusions:

• The dorsal intercalated amygdala (ITC_d) plays a critical role in negative reinforcement and responding to negative stimuli.
• Inhibiting ITC_d optogenetically successfully rescued the extinction deficits in Sapap3-null mice.
• These findings offer insights into the neural basis of negative reinforcement impairments in OCD.