Retrograde Signaling
A form of synaptic communication where the postsynaptic neuron sends chemical signals back to the presynaptic neuron to modulate neurotransmitter release.
In Depth
Endocannabinoids are the primary retrograde messengers in the CNS. When a postsynaptic neuron is strongly activated, it synthesizes endocannabinoids (primarily 2-AG) that travel backward across the synapse to activate CB1 receptors on the presynaptic terminal. This reduces neurotransmitter release — a process called depolarization-induced suppression of inhibition (DSI) or excitation (DSE). This mechanism allows neurons to regulate their own incoming signals and is fundamental to synaptic plasticity.
Further Reading
More in Neuroscience
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.
Amygdala
A brain region central to fear processing, emotional memory, and the stress response. CB1 receptors in the amygdala mediate cannabinoids' effects on anxiety and fear extinction.