“…The transient response mechanism had the anticipated characteristics of a lowvoltage-activated (LVA) T-type Ca 2ϩ channel, including a similar time course of activation and inhibitor sensitivity (Arnoult et al, 1999). LVA Ca 2ϩ channel genes are expressed during rodent spermatogenesis (Espinosa et al, 1999), and the associated currents were detected by whole cell patch clamp methods (Hagiwara and Kawa, 1984;Arnoult et al, 1996aArnoult et al, , 1997Arnoult et al, , 1998Liévano et al, 1996;Santi et al, 1996). Finally, channel activation was associated with acrosome reactions (Arnoult et al, 1996a).…”