Figure 1.

Calculating [Ca²⁺] in dendritic spines during continuous pre- and post-synaptic activity. The model initially calculates the membrane potential during continuous activity by summating the membrane potential changes due to EPSPs and BPAPs from a resting membrane potential of −65 mV. The Ca²⁺ current passing through synaptic NMDARs is then calculated from the membrane potential and glutamate binding kinetics. Finally spine [Ca²⁺] is calculated from Ca²⁺ buffering and diffusion kinetics. Left hand panels show the post-synaptic responses to an epoch of place cell activity spanning 3500 ms. Right hand panels show a 200 ms excerpt from this epoch.