Background: Olanzapine is an atypical antipsychotic with similar pharmacologic properties to droperidol. Due to the current droperidol shortage, the authors' clinical practice has been to substitute olanzapine for droperidol in many situations. At this time, olanzapine is U.S. Food and Drug Administration approved for oral and intramuscular (IM) use only, but due to its increased utility, intravenous (IV) olanzapine was recently approved for use in the study emergency department (ED).

Background: Netrin-1 can either attract or repel neuronal growth cones. Results: The ezrin/radixin/moesin proteins mediate interaction between protein kinase A (PKA) and deleted in colorectal cancer (DCC, a netrin receptor), which controls growth cone tropism. Conclusion: Localized PKA signaling governs axon guidance behavior toward netrin. Significance: This interaction provides insight into the signals governing axon pathfinding, neural development, and potentially other DCC-related functions.

Regulation of the cyclic AMP-dependent protein kinase (PKA) in subcellular space is required for cytoskeletal dynamics and chemotaxis. Currently, spatial regulation of PKA is thought to require the association of PKA regulatory (R) subunits with A-kinase anchoring proteins (AKAPs). Here, we show that the regulatory RIIα subunit of PKA associates with dynamic actin microspikes in an AKAP-independent manner. Both endogenous RIIα and a GFP-RIIα fusion protein co-localize with F-actin in microspikes within hippocampal neuron growth cones and the leading edge lamellae of NG108-15 cells. Live-cell imaging demonstrates that RIIα-associated microspikes are highly dynamic and that the coupling of RIIα to actin is tight, as the movement of both actin and RIIα are immediately and coincidently stopped by low-dose cytochalasin D. Importantly, colocalization of RIIα and actin in these structures is resistant to displacement by a cell-permeable disrupter of PKA-AKAP interactions. Biochemical fractionation confirms that a substantial pool of PKA RIIα is associated with the detergent-insoluble cytoskeleton and is resistant to extraction by a peptide inhibitor of AKAP interactions. Finally, mutation of the AKAP-binding domain of RIIα fails to disrupt its association with actin microspikes. These data provide the first demonstration of the physical association of a kinase with such dynamic actin structures, as well as the first demonstration of the ability of type-II PKA to localize to discrete subcellular structures independently of canonical AKAP function. This association is likely to be important for microfilament dynamics and cell migration and may prime the investigation of novel mechanisms for localizing PKA activity.