Figure 5. How does Ca²⁺ change CBF?

Shown are possible mechanisms by which Ca²⁺ could influence CBF, the different pharmacological tools used to probe for these possibilities experimentally, and the expected outcomes if the putative mechanism was inhibited by the drug. 1, Ca²⁺ acts either through calmodulin or directly to stimulate a Ca²⁺-dependent kinase; blocking calmodulin or phosphatases should then alter the coupling between [Ca²⁺]_i and CBF as depicted. 2, Ca²⁺ acts either through calmodulin or directly to stimulate a Ca²⁺-dependent phosphatase; blocking calmodulin or phosphatases should again alter the coupling between [Ca²⁺]_i and CBF as depicted. 3, Ca²⁺ acts directly on a ciliary response element; no inhibitor should influence the coupling between [Ca²⁺]_i and CBF.