I do not believe mercury is neutered as I have heard it described. Asexual would seem more appropriate, as in this posts target link. Though to be honest, that doesn't describe the situation any better. The only one that does, is to call Mercury, the planet of androgeny...
http://www.astrologyweekly.com/forum/showthread.php?t=13598
http://www.astrologyweekly.com/forum/showthread.php?t=13598