rest and movement, and might signal neural plasticity due to the intracellular cascades brought on by the rapid influx of calcium. While these roles are not mutually exclusive, most attractive is the hypothesis that persistent bursting promotes a motor state resistant to change, potentially explaining the akinetic symptoms of Parkinson's disease. As a drug target Calcium channel blockers (CCB) such as mibefradil can also block L-type calcium channels, other enzymes, as well as other channels. Consequently, research is still being conducted to design highly selective drugs that can target T-type calcium channels alone. Cancer Furthermore, since T-type calcium channels are involved in proliferation, survival and cell cycle progression of these cells, they are potential targets for anticancer therapy. As mentioned above, blockage or down regulation of the T-type calcium channels causes cytostasis in tumors; but this blockage or down regulation of the T-channels may also induce cytotoxic effects. Consequently, it is not yet clear what the benefits or disadvantages of targeting T-type calcium channels in anticancer therapy are. On the other hand, a combined therapy involving administration of a T-type channel antagonist followed by cytotoxic therapy is currently in its clinical trial phase. Painful Diabetic Neuropathy (PDN) In addition, drugs used for treating PDN are associated with serious side effects and target specifically the CaV3.2 isoform (responsible for development of neuropathic pain in PDN) could reduce side effects. As a result, research to improve or design new drugs is currently on-going. Parkinson's disease T-type calcium channels represent an alternative approach to Parkinson's disease treatment as their primary influence is not concerning the central dopaminergic system. For example, they offer great potential in reducing side effects of dopamine replacement therapy, such as levodopa-induced dyskinesia. The co-administration of T-type calcium channel blockers with standard Parkinson's disease medications is most popular in Japan, and several clinical studies have shown significant efficacy. However, most of these drugs are experimental and operate in a non-specific manner, potentially influencing sodium channel kinetics as well as dopamine synthesis. Novel T-type calcium channel inhibitors have recently been discovered which more selectively target the CaV3.3 channel sub-type expressed in central motor neurons, showing robust modulation in a rodent and primate models of Parkinson's disease. References Calcium channels