Membrane potential response to a 400 ms current injection at the soma is altered by biochemical calcium transients in eleven adjacent spines. a, Membrane potential response at the soma in response to a 400 ms 2 nA depolarizing current injection at the soma. b, Action potentials at the soma in response to a depolarizing current injection at the soma superimposed with PF-induced calcium release (20 ms before the start of the current injection). c, Corresponding calcium transients at the spine with an inset magnifying the lower amplitude responses. d, Corresponding changes in BK channel conductance at the spine. Note that in c and d, the solid red and green lines directly superimpose beyond 0.3 s.