Saturday, July 11, 2009

Lithium and inositol signaling

Anyone following the literature on inositol signaling and Lithium? The plot thickens. Here is a brief summary and later I'll talk about things in detail in future posts for those more interested in learning more.

In brief, there's been a longstanding notion that perturbation of phosphoinositide signaling may well be the underlying cause of bipolar disorder. The reason for this is that Lithium, the most well-known mood stabilizer drug is known to decrease intracellular inositol, and more recently two other well-known anticonvulsant mood stabilizers have been shown to have the same effect. However, functional studies since then have been contradictory. Some groups have shown that intracellular inositol depletion per se does not perturb phosphoinositide signaling, using knockout animal models; recently another group published data using the ameba Dictyostelium, and human white blood cells, consistent with the idea that Lithium perturbs PIP3 signaling. The question that emerges is whether there is some methodological reason for these contradictory findings. Stay posted!