The systemic administration of noncompetitive N-methyl-D-aspartate (NMDA) receptor antagonists has been considered as a pharmacological model of schizophrenia. In the present work, we used in vivo microdialysis to examine: first, the effects of MK-801, on the efflux of glutamate and serotonin (5-HT) in the medial prefrontal cortex (mPFC) of the rat; second, whether the MK-801-induced changes in...

In the present study, we have investigated the effects of prolonged inhibition of NMDA receptor by infusion of subtoxic dose of MK-801 to examine the modulation of GABA receptor binding and GABA receptor subunit mRNA level in rat brain. It has been A A reported that NMDA-selective glutamate receptor stimulation alters GABA receptor pharmacology in cerebellar granule neurons in vitro A by alteri...

MK-801 impaired social recognition potency of adult male rats when given immediately after the initial interaction with a juvenile rat. Administration of kynurenic acid prior to the initial interaction protected the adults against recognition deficits induced by MK-801. When re-exposed at a delay of 30 min to the familiar juvenile, social investigation in the adults was significantly reduced. T...

Pretreatment with an uncompetitive NMDA receptor antagonist, dizocilpine [(+)MK-801; six daily injections of 0.1 or 0.2 mg/kg, i.p.] significantly enhanced subsequent 1.5 g/kg ethanol-induced conditioned taste aversion (CTA). In a control experiment, dizocilpine (0.05-.2 mg/kg) produced only a marginal CTA. Thus, pre-exposure to low, non-aversive doses of MK-801 may sensitize rats to the aversi...

We studied the effects of desipramine, alprazolam, muscimol and dizocilpine (MK-801) (alone or associated with desipramine) in the forced swimming test in rats after long-lasting termination of chronic exposure to vehicle and pentylenetetrazol. Sensitisation with pentylenetetrazol was ineffective in changing immobility time in the forced swimming test compared to vehicle treatment; pentylenetet...

Antagonists of N-methyl-D-aspartate receptors (NMDAR) have psychotomimetic effects in humans and are used to model schizophrenia in animals. We used high-density electrophysiological recordings to assess the effects of acute systemic injection of an NMDAR antagonist (MK-801) on ensemble neural processing in the medial prefrontal cortex of freely moving rats. Although MK-801 increased neuron fir...

The removal of a major hippocampal afferent system, the glutamatergic fibers from the entorhinal cortex, results in transneuronal changes in postsynaptic inhibitory neurons using gamma-aminobutyric acid (GABA) as a neurotransmitter. This study shows that these transneuronal alterations are reduced by the selective N-methyl-D-aspartate (NMDA) receptor antagonist (+)-MK-801. Thus, systemic inject...

We report here the results of experiments designed to evaluate whether a specific NMDA receptor antagonist, (+)-5-methyl-10,11-dihydro-5H-dibenzo[a,b]cyclohepten-5,10-imine maleate (MK-801), blocks the phase shifting effects of light on the circadian rhythm of wheel-running activity in golden hamsters. Intraperitoneal administration of (+)-MK-801 produced a dose-dependent blockade of both light...

The N-methyl-D-aspartate receptor (NMDAR), a pivotal entity for synaptic plasticity and excitotoxicity in the brain, is a target of psychotomimetic drugs such as phencyclidine (PCP) and dizolcipine (MK-801). In contrast, a related glutamate receptor, the alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate/kainate receptor GluR1, is weakly sensitive to these drugs. Three point mutations on Glu...

Pretreatment with an uncompetitive NMDA receptor antagonist, dizocilpine [( + )MK-801; six daily injections of 0.1 or 0.2 mg/kg, i.p.] significantly enhanced subsequent 1.5 g/kg ethanol-induced conditioned taste aversion (CTA). In a control experiment, dizocilpine (0.05-0.2 mg/kg) produced only a marginal CTA. Thus, pre-exposure to low, non-aversive doses of MK-801 may sensitize rats to the ave...