Fig. 2.

Dendritic Ca²⁺ changes evoked by coincident EPSPs-bAPs in control neurons are of similar amplitude to those evoked by bAPs alone. (A) Simultaneous current-clamp and Ca²⁺ imaging in a control CA1 neuron. (B) Responses after application of D, L-APV (100 µM) to the same neuron. The top traces in A and Β represent the Ca²⁺ levels estimated by changes in OGB-1 fluorescence, expressed as % ΔF/F, which is proportional to Ca²⁺ concentration. The middle traces are the simultaneous recordings of membrane voltage (red), and the bottom ones, of membrane current (blue); action potentials are truncated for clarity. Arrowheads mark the onset of afferent extracellular stimulation. All data are from a sequential recording from the same CA1 pyramidal neuron. The same figure scheme is used in Fig. 3. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)