THE SPOOKY purple glow emanating from the Zenith Gallery, in its new location on Seventh Street, can mean just one thing -- the annual neon show has opened.

Rather than just bending the tubes into various squiggles, the artists are combining them with anything they can get their hands on: marble, ceramics, a trombone, a '50s milkshake mixer.

The lurid light curls catlike around familiar household objects. Margery Goldberg, one of 12 neon artists exhibiting, wraps it around a mirror or uses the line of light to further define the shape of her wood sculptures. Art Deco clocks by Ian Macartney and Doug Story replicate the ones mass-produced in the neon heyday of the '30s.

The light doesn't stand alone but as part of an image. In photos by Kenneth Wyner, neon accentuates the lines of force in Dulles airport architecture or backlights a swimming pool. In Jerry Berta's delightful ceramic pieces, neon urges us to EAT. Berta's cunning glazed diners and theaters are small-scale nostalgia pieces. His neon-lit hamburgers and hot dogs are right on target, and play to our prejudice that neon means cheap bars and eat-at-Joes.

That was not quite the image its inventor Georges Claude had in mind when he introduced it in 1910 -- and neon did play very well up 'til World War II. Then it became so . . . Vegas. So much for "the noble gases" -- which is another name for inert gases like neon (which makes a firey orange-red), argon (which produces a nice soft lavender alone, or blue when mercury is added) and pink-purple krypton.

In the past decade, artists have recharged the image of neon. But somehow it all seems to have been tried before, on a much larger scale, over Times Square. They just can't recapture that honkytonk grandeur.

Michael Pinciotti doesn't even try -- and his work flickers with strangeness and humor. He makes absurd drawings of houses -- "The Temple of Well Being" -- photographs them, blows up the photo and incorporates tubes of neon in the picture. In "The Knowledge of Depth," he outlines the perspective lines along the roof in neon. His new lines pose glowing questions.

Patricia Tobacco Forrester has moved her landscapes of sinewy plants in riotous colors out of Rock Creek Park to places like Madeira and Costa Rica. They continue to be an exotic somewhere -- where you may or may not want to wander.

Some may see her watercolors as merely pretty -- they are certainly eye pleasing. But she defies the inherent sweetness of the medium. There is something slightly sinister in the tortuous branches and their twisted shadows -- which she colors aqua, pink -- that fall on the tree trunk below.

Always working out-of-doors, she very subtly paints animation into plant life. Bold birds of paradise come together, Hitchcock style, against a brooding background in "Flocking." She invents a plant life that regards the animal world with indifference -- a hierarchy in a field of sunflowers. In her large diptych "Sunflowers Overhead," heavy blooms dangle over the viewer, their leaves flapping like green hands, and two faces of flowers stare out, emperor and empress, surrounded by the floral court that bows to them.

Roni Horn is a New York sculptor whose works on paper may be seen at the Winston Gallery. In sculpting she concerns herself with such concepts as density, compression and what she calls "the solitude of heavy things." In the past decade, she has made floor pieces -- lead mats and rubber slabs that seem to press down into the floor, and sheets of lead pressed together to form manmade rocks -- placing them in isolation in large, empty rooms.

It's solemn stuff, and her collaged paintings are small-scale ruminations on these sculptural issues. Earth-toned pairs of shapes suggest amorphic rocks. Appropriately serious words for this would be "the interplay of duality" -- but what you're doing is comparing the features of the two shapes as if they were fraternal twins.

Horn has obviously thought long and hard about each small artistic choice -- the exact placement of these organic shapes, and their textures: She uses pastel, powdered pigment and varnish to provide the viewer a textural entry point to this difficult work.

Her work is not strictly minimalist; it's not as cleanly dehumanized. Just as the bare gallery room is the natural environment for her simple sculptures, her drawings are set in a background of naturalistic smudges and fingerprints. The artist leaves her mark.

LIGHT MOTIFS --

At Zenith Gallery, 413 Seventh St. NW, through March 5. Hours are 10 to 6 Monday through Friday, 11 to 6 Saturday and noon to 4 Sunday.

PATRICIA TOBACCO FORRESTER --

At Fendrick Gallery, 3059 M St. NW, through February 27. Gallery hours are 9:30 to 5:30 Tuesday through Saturday.

RONI HORN: DRAWINGS --

At Winston Gallery, 1204 31st St. NW, through February 27. Hours are 10 to 6 Tuesday through Saturday.