Propylparaben (Propyl parahydroxybenzoate) is an antimicrobial agent, preservative, flavouring agent

Experimental conditions were as follows: a) basal recordings during which artificial cerebrospinal fluid (ACSF) (in mM: NaCl,125; KCl, 3; Na2HPO4, 1.25; NaHCO3, 25; MgCl2, 2; CaCl2, 2-D-(+)-glucose, 10; gassed with a mixture of 95% O2–5% CO2) was perfused; b) ACSF plus Propylparaben(PPB) (500 μM); c) 4-AP (100 μM) in Mg2+free-ACSF; d) 4-AP in Mg2+free-ACSF plus vehicle (dimethyl sulfoxide, DMSO at 0.04%); e) 4-AP in Mg2+free-ACSF plus drugs (phenytoin (PHT), 200 μM; PPB, 200 and 7500 μM). Each experimental condition lasted for 10 min. The onset of 4-AP-induced epileptiform activity was considered when bursts of 5 of more consecutive action potentials (APs) were present. The number of APs and excitatory postsynaptic potentials (EPSPs) greater than 1 mV and less than 10 mV of amplitude were quantified during periods of 5 min for each experimental condition[2]