TY - JOUR T1 - Diverse Voltage-Sensitive Dyes Modulate GABA<sub>A</sub>Receptor Function JF - The Journal of Neuroscience JO - J. Neurosci. SP - 2871 LP - 2879 DO - 10.1523/JNEUROSCI.5607-09.2010 VL - 30 IS - 8 AU - Steven Mennerick AU - Mariangela Chisari AU - Hong-Jin Shu AU - Amanda Taylor AU - Michael Vasek AU - Lawrence N. Eisenman AU - Charles F. Zorumski Y1 - 2010/02/24 UR - http://www.jneurosci.org/content/30/8/2871.abstract N2 - Voltage-sensitive dyes are important tools for assessing network and single-cell excitability, but an untested premise in most cases is that the dyes do not interfere with the parameters (membrane potential, excitability) that they are designed to measure. We found that popular members of several different families of voltage-sensitive dyes modulate GABAA receptor with maximum efficacy and potency similar to clinically used GABAA receptor modulators. Di-4-ANEPPS and DiBAC4(3) potentiated GABA function with micromolar and high nanomolar potency, respectively, and yielded strong maximum effects similar to barbiturates and neurosteroids. Newer blue oxonols had biphasic effects on GABAA receptor function at nanomolar and micromolar concentrations, with maximum potentiation comparable to that of saturating benzodiazepine effects. ANNINE-6 and ANNINE-6plus had no detectable effect on GABAA receptor function. Even dyes with no activity on GABAA receptors at baseline induced photodynamic enhancement of GABAA receptors. The basal effects of dyes were sufficient to prolong IPSCs and to dampen network activity in multielectrode array recordings. Therefore, the dual effects of voltage-sensitive dyes on GABAergic inhibition require caution in dye use for studies of excitability and network activity. ER -