Differential protective effects of typical versus atypical antipsychotic
drugs in a phencyclidine microelectrode array model of schizophrenia
Abstract
Abstract Phencyclidine (PCP), a non-competitive N-methyl-D-aspartate
receptor antagonist, is known to produce schizophrenia-like psychosis in
humans, including positive and negative symptoms as well as cognitive
dysfunction. Moreover, acute administration of PCP can emulate
corresponding behavioral symptoms in rodents. We investigated the effect
of PCP and the possible rescuing potential of typical and atypical
antipsychotic drugs (APDs) in vitro on spontaneously active neuronal
networks. To this end, murine primary cortical cells were cultured on
microelectrode arrays (MEAs). Concentration-response curves of PCP
ranging from 0.01 to 200 µM were generated and network spike and burst
rate as well as burst peak firing rate (PFR) and burst duration was
measured in stable two-minute recordings. Measurements were done with
and without pre-incubation with the APDs aripiprazole, clozapine, and
haloperidol. We found a concentration-dependent network activity
suppression reflected by a decrease in captured spike rate and network
PFR upon PCP application relative to baseline. Preexposure with any of
the three APDs mediated a right-shift of the PCP concentration-response
curve (spike rate, PFR). However, as assessed by their IC50 values and
Hill coefficients, the atypical APDs aripiprazole and clozapine
exhibited a 20- to 30-fold protective potency—higher than the typical
APD haloperidol (6-fold). In summary, a disruptive network effect of PCP
as well as a protection by APDs could be demonstrated in the order of
potency: clozapine > aripiprazole
>> haloperidol. We propose this simple,
noninvasive setup as a plausible electrophysiological model for testing
current and future pharmaceuticals against schizophrenia-spectrum
disorders.