Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.16.2 (PCP)
 3,761 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Glutamate receptor-dependent neural plasticity is thought to be implicated in memory processes. Ionotropic N-methyl-D-aspartate- (NMDA) sensitive and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate- (AMPA) sensitive glutamate receptors have been particularly studied for their role in synaptic plasticity. Drugs can alter AMPA and NMDA receptor neurotransmission by competing for the glutamate site or other sites on these receptor proteins. Variants of the protein subunits forming AMPA and NMDA heteromers contribute to the complexity of pharmacological activity at these receptors. The NMDA receptor has numerous modulatory centers, including the glycine binding site, NR2B protein specific binding site, and an intrachannel (PCP) binding site. In this study, the accuracy and rate of rats performing under a Fixed Consecutive Number (FCN) operant task were measured after administrations of site-selective AMPA and NMDA receptor modulators. Test compounds included two glycine site NMDA agonists [(+)HA 966 and D-cycloserine], two NR2-B site NMDA antagonists (eliprodil and ifenprodil), an NMDA channel blocking antagonist (MK 801), and a competitively acting AMPA receptor antagonist (NBQX). The accuracy of FCN performance was not affected by response-rate-altering doses of (+) HA 966, D-cycloserine, eliprodil, ifenprodil, or NBQX. MK 801, on the other hand, reduced performance accuracy at several doses. These results are consistent with earlier studies suggesting that AMPA antagonists minimally affect working memory and that glycine and NR2B protein-specific modulatory sites may have advantages as targets for the development of medications intended to alter NMDA receptor-mediated transmission.
Neurobiol Learn Mem 2002 Sep
PMID:Site-selective N-methyl-D-aspartate and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate antagonists produce distinct effects in rats performing complex discriminations. 1243 22

Although subchronic phencyclidine (PCP) administration is recognized as a probative method to model schizophrenia-like symptoms in animals, only a few sets of data support the hypothesis of a cognitive prefrontal cortex (PFc) dysfunction in PCP-treated monkeys and rodents. Two experiments were here conducted to further test the integrity of prefrontal function in two versions of a memory for temporal order (MTO) task administered to rats. Original versions of this task elaborated by Kesner repeatedly yielded moderate to severe performance deficits in PFc lesioned rats. MTO assessment in an eight-arm radial maze consisted in a recency discrimination between two arms previously explored in the context of sequential forced choices. In Experiment 1, 16 naive Long-Evans rats were pre-trained on a variable version of the MTO task involving randomly re-mixed sequences until they reached a group criterion. Then, rats were treated daily for 21 days with PCP (10mg/kg) or saline vehicle and were tested on the same task approximately 20 h after an injection. The performance of the groups did not differ. In Experiment 2, 16 naive Long-Evans rats untrained prior to treatment received 27 daily injections of either PCP (10mg/kg) or saline vehicle and were tested, 20 h after each injection, on a constant version of the MTO task. This time, a fixed set of four sequences of successive arm entries was repeated within each daily session as well as across days. Again, prolonged PCP exposure failed to impair discrimination of temporal order despite the stability of sequential information over time. These negative results are not consistent with long-lasting hypofrontality, a major landmark of human schizophrenia, in the PCP rat model.
Neurobiol Learn Mem 2003 Sep
PMID:Schizophrenia-like syndrome inducing agent phencyclidine failed to impair memory for temporal order in rats. 1293 31