DESCENT OF HEATHER

If imitation is the sincerest form of flattery, then the creators of Mystery Science Theater 3000 have reason to be proud -- well, maybe. Mystery Melrose Theater, a weekly gathering on the alternative-rock bulletin-board service SonicNet (Internet address: info@sonicnet.com), is a roasting of Melrose Place on-line.

The setup is similar to that of MST3K: Folks who log on exchange witticisms while watching the Monday-night soap. At least that's how it's supposed to work. With SonicNet's pseudonymous Cyberbabe ostensibly trying to maintain order, on-liners tend to indulge in the cyberspace equivalent of wilding, often expending much energy on descriptions of sexual favors they desire from Melrose cast members. Here's a sample of commentary generated by the March 13 episode (all spelling and punctuation courtesy of the participants).

Swamp Thing: Were is traci lords?! Sloth: WHO'S JAKE DOING THIS WEEK? Flesh Relish: that's what I wanna know Wilma: BRING BACK TRACI!!!! Amanda's Tumor: they threw that slut off the show Swamp Thing: YEAH! Satan Himself: they couldn't afford traci anymore

In an attempt to provide the parley with inspiration, SonicNet has invited special guests to sit in. Scheduled for March 13 was Nancy Boy, an unsigned androgyny-flaunting band featuring celebrity progeny Donovan Leitch (son of the ''Mellow Yellow'' guy) and Jason Nesmith (son of ex-Monkee Michael). But Leitch couldn't get his modem to work and Nesmith was unaccounted for, so Melrose kibitzers had to settle for the two other band members, English fellows whose parents aren't famous. They made a brief stab at comparing Melrose to the U.K. soap Coronation Street before giving up and letting the ranters have their way.

Obviously, anyone who's ever wanted to prove he or she could ''do'' MST3K won't get far here. Being cleverer than this bunch is one thing, but trying to get a word in edgewise is something else entirely.