High resolution

Module 10: Figure dendritic Ca2+ wave

Dendritic Ca2+ waves evoked by localized synaptic stimulation of hippocampal CA1 neurons.

The patch electrode on the bottom right was used to introduce the Ca2+ indicator (Furaptra), which has spread throughout the neuron. The dashed arrowhead on the left indicates the position of the electrode used to stimulate some of the local branches of the dendritic tree with a train of 50 pulses at 100 Hz. The electrical trace at the bottom records the change in the membrane potential at the soma. The Ca2+ response was measured in a series of small squares (superpixels) running down the length of the neuron to produce a series of line scans that were then stacked up to produce the spatiotemporal plot shown on the right. Note that the Ca2+ signal initiated at two branch points where the side branches joined the main dendritic shaft. Two waves then spread down the shaft. The dotted vertical line indicates that these two waves began about 500 ms after the beginning of the stimulation, and at different times from each other. Reproduced from Nakamura, T., Lasser-Ross, N., Nakamura, K. and Ross, W.N. (2002) Spatial segregation and interaction of calcium signalling mechanisms in rat hippocampal CA1 pyramidal neurons. J. Physiol. 543:465–480, with permission from Blackwell Publishing; see Nakamura et al. 2002.