Adolescent Brain Builds Dense Synaptic Hotspots, Challenging Pruning Theory
Kyushu University researchers using super-resolution mapping found that adolescence features a dense hotspot of synapses forming along the apical dendrite of Layer 5 neurons, not just widespread pruning; this selective synapse formation emerges between three and eight weeks in mice and depends on intact synapse-building processes, with mutations in schizophrenia-linked genes Setd1a, Hivep2, and Grin1 impairing hotspot formation. The findings, reported in Science Advances, suggest the pruning-centric view of adolescence is incomplete and future work will identify brain regions where these connections form and whether similar mechanisms occur in humans.
