2-Amino-7-phosphonoheptanoic acid (2-APH) infusion into entopeduncular nucleus protects against limbic seizures in rats.

Motor limbic seizures occur following a systemic injection of pilocarpine (380 mg/kg) in rats. Focal injection of the selective N-methyl-D-aspartate receptor antagonist, (+/-)-2-amino-7-phosphonoheptanoic acid (2-APH, 5-20 pmol), bilaterally into the entopeduncular nucleus (EP) prior to pilocarine blocks these seizures. Muscimol (50 pmol), a potent gamma-aminobutyric acid receptor agonist, injected bilaterally into EP produces a similar protection against pilocarpine-induced seizures. Thus by blocking excitatory neurotransmission or facilitating inhibition within the EP, the severity of limbic seizures can be reduced.