Ifenprodil, an antagonist of NMDA receptors containing the NR2B subunit, was expected to exhibit anticonvulsant action in rat pups up to the third postnatal week because of predominance of NR2B subunit at early development. Cortical epileptic afterdischarges (ADs) were used to study possible effects on threshold current intensities and duration of ADs in 12-, 15-, 18-, and 25-day-old rats. A series of 18 stimulation series with stepwise increasing current intensities (from 0.2 to 15 mA) was applied with 10-min intervals. The first experiment studied rats pretreated with ifenprodil (20 or 40 mg/kg), the second experiment studied an effect of ifenprodil on already present ADs-the dose of 20 mg/kg was administered after stimulation with the 3.5-mA current intensity. Pretreatment with ifenprodil resulted in an anticonvulsant effect in 15-day-old rats only, on the contrary, proconvulsant action was found in 18- and 25-day-old animals (decrease of thresholds especially for transition into the second, limbic type of ADs and increase in duration of ADs). Anticonvulsant effect was found in 12-, 15-, and 18-day-old rats in the second experiment-ADs were shortened. In contrast, no effect was observed in 25-day-old animals. An anticonvulsant action of ifenprodil is not only age-dependent but also activation-dependent.

• MeSH
• Anticonvulsants therapeutic use   MeSH
• Electric Stimulation MeSH
• Animals, Newborn MeSH
• Pentylenetetrazole MeSH
• Piperidines therapeutic use   MeSH
• Rats, Wistar MeSH
• Receptors, N-Methyl-D-Aspartate antagonists & inhibitors   MeSH
• Aging physiology   MeSH
• Seizures chemically induced   drug therapy   physiopathology   MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Anticonvulsants MeSH
• ifenprodil MeSH Browser
• Pentylenetetrazole MeSH
• Piperidines MeSH
• Receptors, N-Methyl-D-Aspartate MeSH