High resolution

Module 10: Figure input-specific signalling

Input-specific localized Ca2+ signals and global Ca2+ signals in the dendritic tree of neurons.

The panel on the left shows a portion of a typical dendritic tree receiving multiple inputs from two neurons. The synaptic endings from neuron 1 are shown in brown, whereas those from neuron 2 are in green. During presynaptic stimulation of the endings from neuron 1 (yellow arrows in the top panel on the right), only those spines that are activated display Ca2+ signals. By contrast, postsynaptic stimulation via a back-propagating action potential (single arrow in the lower right-hand panel) results in a Ca2+ signal developing uniformly throughout the dendrites and into all of the spines. These more global events, where Ca2+ increases over larger regions of the neuron, can also invade the nucleus, with important implications for gene activation.