Beyond Hebb

Synapses are not lost to neglect — they are actively executed. A glutamatergic save-me signal protects the stimulated branch while a RhoA punishment signal travels laterally to dismantle its neighbours on the same cell. The 2024–25 climbing-fibre work then removes neurotransmission entirely and finds the winner is still chosen, which demotes transmission from arbiter of selection to motor of execution. Reads pruning efficiency as one axis running from the under-pruned circuits of autism through ordinary cognition to the over-pruning of schizophrenia and the unprotected synapse of Alzheimer's.