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. Author manuscript; available in PMC: 2010 Dec 21.
Published in final edited form as: Cereb Cortex. 2007 Jun 14;18(2):407–423. doi: 10.1093/cercor/bhm075

Figure 8.

Figure 8

Priming facilitated the propagation of Ca2+ waves into and through the soma and enhanced the hyperpolarization and depolarization. (A) Trains of synaptic stimulation (30 pulses at 100 Hz) evoked Ca2+ waves in the primary apical dendrite and a basal dendrite of the rat cell shown at left. When the stimulus was preceded by a spike train (17 Hz, 3 s), the Ca2+ waves propagated into and through the soma and were accompanied by a distinct hyperpolarization. Ca2+ waves triggered by the same stimulation but without prior spike train priming propagated shorter distances, had smaller amplitude in the soma, and were not accompanied by distinct hyperpolarizations. (B) Puffs of ACPD (30 ms) were applied onto this rat neuron at variable intervals following priming spike trains (17 Hz, 3 s). The maximum amplitude of somatic [Ca2+]i rises, as well as the magnitudes of the hyperpolarization and depolarization, decreased as the amount of time since priming increased. (C) UV flashes over the soma of a rat cell filled with NPE-caged IP3 (97 μM) triggered [Ca2+]i rises and hyperpolarizations. Both the maximum amplitude of somatic [Ca2+]i rises and the hyperpolarization magnitude decreased as the amount of time since priming increased. Optical data shown here were corrected for the tissue autofluorescence that results from exposure to the uncaging beam. (D) Maximum amplitude of ACPD puff-evoked somatic [Ca2+]i rises versus time since priming for 5 rat cells. The amplitude of [Ca2+]i rises in the soma correlated negatively (P <0.05) with the amount of time since priming for all 5 cells. (E) The magnitude of the hyperpolarization triggered by puffs of ACPD or by uncaging of NPE-caged IP3 versus time since priming for 9 rat cells. Hyperpolarization magnitude correlated negatively (P <0.05) with the amount of time since priming for all 9 cells. (F) The magnitude of the ACPD puff–evoked depolarization versus time since priming for 6 rat cells. Depolarization magnitude decreased as the amount of time since priming increased for all 6 cells. A negative correlation (P<0.05) was seen for only 3 of the 6 cells.