Dendrites are the main input structures of neurons, receiving and integrating thousands of excitatory synaptic inputs. Compartmentalisation is a key feature of dendrites with the intricate structure of spine necks creating single synapse electrical and chemical compartments. However, the morphological features compartmentalising along single branches are less well understood.Using super-resolution techniques (Stimulated Emission Depletion Microscopy and expansion microscopy) of granule cell dendrites, we observed localized reductions in the dendritic shaft diameter to values below 300 nm that we confirmed with EM. These dendritic shaft constrictions (DSCs) occurred primarily in the distal dendrites (>150 µm) creating dendritic sub-compartments. Computational modelling and two-photon glutamate uncaging with intradendritic Ca2+ imaging show that dendritic sub-compartments at distal input sites lead to rapid saturation of local synaptic voltage signals and NMDA receptor recruitment. Next, we investigated how inputs in distal and proximal dendritic compartments interact. Using glutamate iontophoresis, dendritic plateau potentials were elicited in distal dendritic compartment preferentially in response to gamma patterned input. The distal-induced plateau potentials were associated with large, prolonged NMDA dependent Ca2+ plateaus at the distal input site and proximal Ca2+ transients mediated by intracellular Ca2+ release. Experimental data show that distal inputs gate a branch-specific potentiation of proximal inputs. While computational modelling predicts that this novel branch specific cooperative plasticity increases information storage in granule cell dendrites.Taken together, the data suggest DSCs create high impedance compartments in the distal dendrite that favor the generation of NMDA plateau potentials. Distally-induced plateau potentials gate proximal plasticity via intracellular Ca2+ release