title: Comparison of the long-term behavioral effects of neonatal exposure to retigabine or phenobarbital in rats.
abstract: Anticonvulsant drugs, when given during vulnerable periods of brain development, can have long-lasting consequences on nervous system function. In rats, the second postnatal week approximately corresponds to the late third trimester of gestation/early infancy in humans. Exposure to phenobarbital during this period has been associated with deficits in learning and memory, anxiety-like behavior, and social behavior, among other domains. Phenobarbital is the most common anticonvulsant drug used in neonatology. Several other drugs, such as lamotrigine, phenytoin, and clonazepam, have also been reported to trigger behavioral changes. A new generation anticonvulsant drug, retigabine, has not previously been evaluated for long-term effects on behavior. Retigabine acts as an activator of KCNQ channels, a mechanism that is unique among anticonvulsants. Here, we examined the effects retigabine exposure from postnatal day (P)7 to P14 on behavior in adult rats. We compared these effects with those produced by phenobarbital (as a positive control) and saline (as a negative control). Motor behavior was assessed by using the open field and rotarod, anxiety-like behavior by the open field, elevated plus maze, and light-dark transition task, and learning/memory by the passive avoidance task; social interactions were assessed in same-treatment pairs, and nociceptive sensitivity was assessed via the tail-flick assay. Motor behavior was unaltered by exposure to either drug. We found that retigabine exposure and phenobarbital exposure both induced increased anxiety-like behavior in adult animals. Phenobarbital, but not retigabine, exposure impaired learning and memory. These drugs also differed in their effects on social behavior, with retigabine-exposed animals displaying greater social interaction than phenobarbital-exposed animals. These results indicate that neonatal retigabine induces a subset of behavioral alterations previously described for other anticonvulsant drugs and extend our knowledge of drug-induced behavioral teratogenesis to a new mechanism of anticonvulsant action.
authors.affiliation: Department of Pharmacology & Physiology, Georgetown University School of Medicine, United States.
authors.forename: Sari
authors.initials: S
authors.lastname: Frankel
authors.affiliation: Department of Pharmacology & Physiology, Georgetown University School of Medicine, United States.
authors.forename: Natalia
authors.initials: N
authors.lastname: Medvedeva
authors.affiliation: Department of Pharmacology & Physiology, Georgetown University School of Medicine, United States.
authors.forename: Samuel
authors.initials: S
authors.lastname: Gutherz
authors.affiliation: Department of Pharmacology & Physiology, Georgetown University School of Medicine, United States.
authors.forename: Catherine
authors.initials: C
authors.lastname: Kulick
authors.affiliation: Department of Pharmacology & Physiology, Georgetown University School of Medicine, United States.
authors.forename: Alexei
authors.initials: A
authors.lastname: Kondratyev
authors.affiliation: Department of Pharmacology & Physiology, Georgetown University School of Medicine, United States. Electronic address: paf22@georgetown.edu.
authors.forename: Patrick A
authors.initials: PA
authors.lastname: Forcelli
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000502:physiology; D000927:Anticonvulsants / Q000008:administration & dosage / Q000009:adverse effects*; D001007:Anxiety; D001522:Behavior, Animal / Q000187:drug effects*; D002219:Carbamates / Q000008:administration & dosage / Q000009:adverse effects*; D003071:Cognition / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005260:Female; D008297:Male; D008568:Memory / Q000187:drug effects; D010634:Phenobarbital / Q000008:administration & dosage / Q000009:adverse effects*; D010655:Phenylenediamines / Q000008:administration & dosage / Q000009:adverse effects*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D000927:Anticonvulsants; D002219:Carbamates; D010655:Phenylenediamines; C101866:ezogabine; D010634:Phenobarbital
keywords: Anticonvulsant; Antiepileptic drug; Development; Epilepsy; Neonatal