The  tryptophan  metabolite,  kynurenic  acid (KYNA),  is  classically  known  to  be  an antagonist  of ionotropic glutamate receptors. Within the last decade several reports have been published suggesting that KYNA also blocks nicotinic acetylcholine receptors (nAChRs) containing the α7 subunit (α7*). Most of these reports involve either indirect measurements of KYNA effects on α7 nAChR function, or are reports of KYNA effects in complicated in vivo systems.  However, a recent report investigating KYNA interactions with α7 nAChRs failed to detect an interaction using direct measurements of... |