Nicotine therapy in adulthood reverses the synaptic and behavioral deficits elicited by prenatal exposure to phenobarbital.
A major objective in identifying the mechanisms underlying neurobehavioral teratogenicity is the possibility of designing therapies that reverse or offset drug- or toxicant-induced neural damage. In our previous studies, we identified deficits in hippocampal muscarinic cholinergic receptor-induced membrane translocation of protein kinase C (PKC)gamma as the likely mechanism responsible for adverse behavioral effects of prenatal phenobarbital exposure. We therefore explored whether behavioral and synaptic defects could be reversed in adulthood by nicotine administration. Pregnant mice were given milled food containing phenobarbital to achieve a daily dose of 0.5-0.6 g/kg from gestational days 9-18. In adulthood, offspring showed deficits in the Morris maze, a behavior dependent on the integrity of septohippocampal cholinergic synaptic function, along with the loss of the PKCgamma response. Phenobarbital-exposed and control mice then received nicotine (10 mg/kg/day) for 14 days via osmotic minipumps. Nicotine reversed the behavioral deficits and restored the normal response of hippocampal PKCgamma to cholinergic receptor stimulation. The effects were regionally specific, as PKCgamma in the cerebellum was unaffected by either phenobarbital or nicotine; furthermore, in the hippocampus, PKC isoforms unrelated to the behavioral deficits showed no changes. Nicotine administration thus offers a potential therapy for reversing neurobehavioral deficits originating in septohippocampal cholinergic defects elicited by prenatal drug or toxicant exposures.
Beer
Avital
A
The Ross Laboratory for Studies in Neural Birth Defects, Department of Anatomy and Cell Biology, The Hebrew University-Hadassah Medical School, Jerusalem, Israel.
Slotkin
Theodore A
TA
Seidler
Frederic J
FJ
Aldridge
Justin E
JE
Yanai
Joseph
J
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D015415:Biomarkers; D001933:Brain Stem / Q000187:drug effects / Q000378:metabolism; D002217:Carbachol / Q000494:pharmacology; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism; D003600:Cytosol / Q000187:drug effects / Q000378:metabolism; D005260:Female; D006426:Hemicholinium 3 / Q000494:pharmacology; D006993:Hypnotics and Sedatives / Q000037:antagonists & inhibitors* / Q000633:toxicity*; D007527:Isoenzymes / Q000378:metabolism; D018782:Maze Learning / Q000187:drug effects; D051379:Mice; D018721:Muscarinic Agonists / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects / Q000473:pathology; D014179:Neurotransmitter Uptake Inhibitors / Q000494:pharmacology; D009538:Nicotine / Q000627:therapeutic use*; D018722:Nicotinic Agonists / Q000627:therapeutic use*; D010275:Parasympathetic Nervous System / Q000187:drug effects; D010634:Phenobarbital / Q000037:antagonists & inhibitors* / Q000633:toxicity*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D011493:Protein Kinase C / Q000378:metabolism; D011978:Receptors, Nicotinic / Q000187:drug effects; D015398:Signal Transduction / Q000187:drug effects; D013550:Swimming / Q000502:physiology; D013569:Synapses / Q000187:drug effects*
D015415:Biomarkers; D006993:Hypnotics and Sedatives; D007527:Isoenzymes; D018721:Muscarinic Agonists; D014179:Neurotransmitter Uptake Inhibitors; D018722:Nicotinic Agonists; D011978:Receptors, Nicotinic; D006426:Hemicholinium 3; D009538:Nicotine; D002217:Carbachol; D011493:Protein Kinase C; D010634:Phenobarbital