If you do use anti-seize on your spark plugs you must be careful not to over torque. It's very easy to strip threads or break plug shells. Most specs say hand tighten until the crush washer touches and turn another 1/2 turn, follow this exactly. Or reduce your torque wrench setting by about 50% (which is really important anytime you use anti-seize, not just on plugs).
One thing to note is that you must use anti-seize on uncoated spark plugs. These are usually the dull or darker shells and guaranteed will corrode with all the magnesium chloride around here, especially with aluminum heads.
Newer plugs and more expensive plugs are shiny due to their nickel or zinc plating, which is to prevent corrosion. That is because they are the one designed to be left installed for 100,000 miles as opposed to the cheap ones (like my 22R-E uses) which you replace regularly. You should not in theory need to anti-seize them, but I've got no experience with anything that uses them (we did not own the 4Runner long enough to do more than oil changes and everything else has been old junk).
They make anti-seize with copper instead of graphite or nickel in suspension just for things that need to be kept from galling but still conduct, like spark plugs and senders. In any case, be sparing with the stuff, just enough to get the job done. That is what I put on my spark plugs. If it causes a reduction in spark energy I can't tell, my truck is slow regardless. I don't fail emissions tests anyway.
'91 Pickup - Imelda
'08 Tacoma TRD - Donna