Prenatal nicotine exposure selectively affects nicotinic receptor expression in primary and associative visual cortices of the fetal baboon.
Exposure to nicotine during pregnancy via maternal cigarette smoking is associated with visual deficits in children. This is possibly due to the activation of nicotinic acetylcholine receptors (nAChRs) in the occipital cortex, which are important in the development of visual mapping. Using a baboon model, we explored the effects of prenatal nicotine on parameters in the primary and associated visual cortices. Pregnant baboons were infused with nicotine (0.5 mg/h, intravenous) or saline from 86 days gestation. At 161 days gestation, fetal brains were collected (n = 5 per group) and the occipital lobe assessed for nAChRs and markers of the serotonergic and catecholaminergic systems using tissue autoradiography and/or high-performance liquid chromatography. Neuronal nAChRs and serotonergic markers were expressed in a region- and subunit-dependent manner. Prenatal nicotine exposure was associated with increased binding for (3) H-epibatidine sensitive nAChRs in the primary visual cortex [Brodmann areas (BA) 17] and BA 18, but not BA 19, of the associative visual cortex (P < 0.05). Markers of the serotonergic or catecholaminergic systems were not significantly altered. Thus, prenatal nicotine exposure is associated with alterations in the cholinergic system in the occipital lobe, which may aid in the explanation of the appearance of visual deficits in children from mothers who smoke during pregnancy.
['Duncan|Jhodie R|JR|', 'Garland|Marianne|M|', 'Stark|Raymond I|RI|', 'Myers|Michael M|MM|', 'Fifer|William P|WP|', 'Mokler|David J|DJ|', 'Kinney|Hannah C|HC|']
D000818:Animals D002395:Catecholamines D005260:Female D005333:Fetus D009474:Neurons D009538:Nicotine D018722:Nicotinic Agonists D009778:Occipital Lobe D010215:Papio D011247:Pregnancy D011877:Radionuclide Imaging D011978:Receptors, Nicotinic D012701:Serotonin D014793:Visual Cortex
nicotinic receptors pregnancy smoking visual cortex calcarine sulcus serotonin