Fear Extinction
The process by which a conditioned fear response is suppressed through repeated exposure to a feared stimulus without the expected aversive outcome. Impaired in PTSD.
In Depth
Fear extinction is not erasure of the original fear memory but formation of a new inhibitory memory. The endocannabinoid system is essential for fear extinction: CB1 receptor activation in the amygdala and prefrontal cortex facilitates extinction learning. THC and CBD both enhance fear extinction in animal models. This mechanism is the primary rationale for cannabinoid therapy in PTSD — cannabinoids may facilitate the extinction of traumatic memories during psychotherapy.
Related Terms
Further Reading
More in Neuroscience
Retrograde Signaling
A form of synaptic communication where the postsynaptic neuron sends chemical signals back to the presynaptic neuron to modulate neurotransmitter release.
Neurogenesis
The process by which new neurons are formed in the brain. In adults, primarily occurs in the hippocampus (dentate gyrus) and olfactory bulb.
Neuroprotection
The preservation of neuronal structure and function against injury, degeneration, or disease.
Neuroinflammation
Inflammation of nervous tissue, involving activation of microglia and astrocytes and release of pro-inflammatory cytokines within the CNS.
Hippocampus
A brain region critical for memory formation, spatial navigation, and stress regulation. Highly enriched in CB1 receptors and particularly sensitive to cannabinoid effects.