To further test the consequence of enhanced Ca2+ uptake rate in mitochondria of Tg mice, we examined the effect of DHPG, a metabotropic glutamate receptor agonist, on Ca2+ response in Tg mice. The effect of DHPG on depolarization pulse-evoked Ca2+ response was diminished in Tg mice (Kubota et al., 2006). This finding is apparently contradictory to the findings in platelets, showing enhanced calcium response to serotonin (Kusumi et al., 1994; Okamoto et al., 1995) or thrombin (Dubovsky et al., 1989; Kusumi et al., 1992). However, it might be in accordance with a recent finding suggesting that G-protein coupled receptor mediated calcium response in olfactory neurons is diminished in bipolar disorder (Hahn et al., 2005).