Nipecotic acid, an uptake blocker, prevents fading of the gamma-aminobutyric acid effect.
In rats under urethane, iontophoretic applications of GABA (30-60 nA) in the str. pyramidale of CA1, showed a rapidly fading inhibitory effect. By contrast, GABA had a well-maintained inhibitory effect in str. radiatum. During iontophoresis of nipecotic acid (30-85 nA) identical applications of GABA in str. pyramidale caused a more prominent depression without fading, which suggests that removal of GABA, by uptake, can at least in part account for 'fading'. Nipecotic acid also prolonged the paired-pulse inhibition, presumably by prolonging the duration of inhibitory postsynaptic potentials.
D000818:Animals; D004357:Drug Synergism; D006624:Hippocampus / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D009118:Muscimol / Q000008:administration & dosage; D009557:Nipecotic Acids / Q000008:administration & dosage*; D011392:Proline / Q000031:analogs & derivatives*; D051381:Rats; D011919:Rats, Inbred Strains; D011963:Receptors, GABA-A / Q000187:drug effects; D005680:gamma-Aminobutyric Acid / Q000008:administration & dosage* / Q000378:metabolism
D009557:Nipecotic Acids; D011963:Receptors, GABA-A; C030278:nipecotic acid; D009118:Muscimol; D005680:gamma-Aminobutyric Acid; D011392:Proline; C010983:homoproline