The basolateral amygdala (ABL) is central to fear conditioning, encoding emotional memories and modulating other memory systems. Fear conditioning involves emotionally neutral stimuli (CS) that become associated with aversive events (US), leading to defensive responses. The ABL is crucial for learning and storing fear-related information, as evidenced by lesion studies showing that destruction of the ABL before training prevents learning, while lesions after training impair memory retention. Lesions also disrupt the association between CS and US, indicating the ABL's role in forming this link. Neural activity in the ABL changes during learning, with increased activity during conditioning and subsequent testing. This is supported by electrophysiological studies showing enhanced responses in ABL cells after fear conditioning. Additionally, long-term potentiation (LTP) in ABL pathways is linked to fear learning, suggesting synaptic plasticity in the ABL underlies fear memory formation. Pharmacological manipulation of the ABL during training also blocks fear conditioning, indicating the ABL's role in acquisition. However, these studies do not fully explain the ABL's role in memory consolidation, as post-training lesions do not impair memory. The ABL may modulate memories stored in other brain regions, but it is not required for the expression of nonassociative responses. The ABL's role in fear conditioning is further supported by functional imaging studies showing increased amygdala activity during early training, which resets as training continues, but is reactivated during testing. This suggests the ABL is involved in both encoding and modulating fear memories. In conclusion, the ABL is essential for encoding fear memories and modulating other memory systems. While it is involved in the plasticity underlying fear learning, it does not modulate itself. The ABL is part of a distributed network that encodes fear memories, with plastic changes also occurring in sensory regions afferent to the ABL. Future research is needed to fully understand the distributed nature of fear memory encoding.The basolateral amygdala (ABL) is central to fear conditioning, encoding emotional memories and modulating other memory systems. Fear conditioning involves emotionally neutral stimuli (CS) that become associated with aversive events (US), leading to defensive responses. The ABL is crucial for learning and storing fear-related information, as evidenced by lesion studies showing that destruction of the ABL before training prevents learning, while lesions after training impair memory retention. Lesions also disrupt the association between CS and US, indicating the ABL's role in forming this link. Neural activity in the ABL changes during learning, with increased activity during conditioning and subsequent testing. This is supported by electrophysiological studies showing enhanced responses in ABL cells after fear conditioning. Additionally, long-term potentiation (LTP) in ABL pathways is linked to fear learning, suggesting synaptic plasticity in the ABL underlies fear memory formation. Pharmacological manipulation of the ABL during training also blocks fear conditioning, indicating the ABL's role in acquisition. However, these studies do not fully explain the ABL's role in memory consolidation, as post-training lesions do not impair memory. The ABL may modulate memories stored in other brain regions, but it is not required for the expression of nonassociative responses. The ABL's role in fear conditioning is further supported by functional imaging studies showing increased amygdala activity during early training, which resets as training continues, but is reactivated during testing. This suggests the ABL is involved in both encoding and modulating fear memories. In conclusion, the ABL is essential for encoding fear memories and modulating other memory systems. While it is involved in the plasticity underlying fear learning, it does not modulate itself. The ABL is part of a distributed network that encodes fear memories, with plastic changes also occurring in sensory regions afferent to the ABL. Future research is needed to fully understand the distributed nature of fear memory encoding.