If DZP shifts receptors from R to R*, then one would predict a
DZP-mediated current. In our hands, a typical oocyte with
exogenously expressed recombinant GABAA receptors exhibits
a maximum GABA-activated current in the range of 1–5 mA. If
DZP were to activate the receptors to a degree that is 1/27,000
that of GABA as predicted from our value of L (Chang &
Weiss, 1999), the DZP-activated current would be in the range
of 0.04–0.19 nA, well below our level of resolution of
approximately 2 nA. Using a high-expression vector and
concentrated cRNA, we have been able to increase substantially
expression levels of the GABA receptor. In fact, the
expression is too high to measure reliably the maximum