Decoding Ca²⁺ signals through cAMP

Transient changes in intracellular Ca²⁺ concentrations drive many biological processes, from gene transcription to growth cone turning. Ca²⁺ elevations can initiate cAMP oscillations, but new results suggest that only specific patterns of Ca²⁺ have this ability. Yuliya Gorbunova (University of Medicine & Dentistry of New Jersey, Piscataway, NJ) and Nicholas Spitzer (University of California, San Diego, CA) anticipate that their results may shift the focus in the field from Ca²⁺ spike frequency to spike timing and pattern.

The two examined reciprocity in Ca²⁺/cAMP signaling in embryonic spinal neurons using fluorescent indicator dyes. In culture, increases in cAMP levels increased the frequency of Ca²⁺ spikes in neurons, whereas decreasing cAMP production had the reverse effect. Blocking Ca²⁺ spikes inhibited cAMP increases. Only specific patterns of induced...