Figure 8.

Ca²⁺ mobilization in crude nuclei isolated from brain cortical neurons. (a) Electromicrograph of a crude nucleus isolated from lysed brain cortical neuron (Materials and Methods). (b–d) Confocal microscopy showing Ca²⁺ redistribution in crude nuclei of cortical neurons as indicated by changes in the fluorescence of rhod-2 AM (Materials and Methods). (b) Ca²⁺ detected in the nucleoplasm of depolarized (high-[K⁺] depolarization, 5 min) and unstimulated neurons. (c) Ca²⁺ redistribution, visualized instantaneously during application of ATP (2.5 mM) and IP₃ (1 μM) to crude nuclei of unstimulated neurons in the presence or absence of 5 mM caffeine, or to nuclei of neurons pretreated by 3 μM thapsigargin (10 min, 37°C). (d) Ca²⁺ redistribution in crude nuclei, evoked by increased extranuclear [Ca²⁺] in the presence or absence of ATP (2.5 mM).