synaptogenese

Synaptogenese, commonly referred to in English as synaptogenesis, is the process by which neurons form synapses with target cells, enabling chemical and electrical communication at neural junctions. It is a central aspect of neural development and remains active in adulthood as a mechanism for learning and experience-driven plasticity.

In mammals, synaptogenese begins during late gestation and accelerates after birth, with rapid increases in synapse numbers across different brain regions. The process involves initial physical contact between axons and dendrites, the development of pre- and post-synaptic specializations, and the maturation of functional synapses. Over time, excess connections are refined or eliminated through pruning, shaping mature neural circuits.

Molecular and cellular mechanisms guiding synaptogenese include cell adhesion molecules such as neurexins and neuroligins, as well as other synaptic organizers. Astrocytes release factors like thrombospondins that promote excitatory synapse formation, while microglia participate in activity-dependent pruning. Intracellular signaling cascades regulate cytoskeletal rearrangements, vesicle trafficking, and receptor recruitment, notably the insertion and maturation of postsynaptic receptors such as AMPA receptors.

Functional maturation of synapses encompasses neurotransmitter release, receptor expression, and the establishment of synaptic strength through plasticity processes such as long-term potentiation and long-term depression. Neural activity and experience shape the rate, timing, and pattern of synaptogenesis, contributing to learning and memory.

Disruptions to synaptogenese are linked with neurodevelopmental and psychiatric conditions, including autism spectrum disorders and Rett syndrome. Research employs imaging, electrophysiology, and various model systems to understand how timing, molecular cues, and activity regulate synapse formation and refinement.