Reduced adolescent risk-assessment and lower nicotinic beta-2 expression in rats exposed to nicotine through lactation by forcedly drinking dams. (10th August 2019)

• Record Type: Journal Article
• Authors: Faure, Alexis; Zoratto, Francesca; Chirico, Doriana; Romano, Emilia; Mancinelli, Rosanna; Saso, Luciano; Callebert, Jacques; Laviola, Giovanni; Granon, Sylvie; Adriani, Walter
• Is Part Of: Neuroscience. Volume 413(2019)
• Page Start: 64
• Page End: 76
• Publication Date: 2019-08-10
• Subjects: Breast feeding -- Neuro-developmental sequelae -- Pre-frontal cortex -- Elevated Plus Maze -- Risk-assessment behaviour -- Juvenile and adolescent rats; Neurochemistry -- Periodicals; Neurophysiology -- Periodicals; Neurology -- Periodicals; Neurochimie -- Périodiques; Neurophysiologie -- Périodiques; Neurochemistry; Neurophysiology; Electronic journals; Periodicals; Electronic journals; 612.8
• DOI: 10.1016/j.neuroscience.2019.06.014
• Languages: English
• ISSNs: 0306-4522

Abstract

Abstract: Few animal studies focus on consequences of nicotine postnatal exposure, particularly through lactation. We have recently shown that forced nicotine drinking elevates maternal care, paradoxically provoking arousal and stress in pups. Present work aimed to evaluate the specific contribution of altered maternal cares, compared to the sequelae merely due to nicotine effects. Two groups were compared to water-drinking control dams: (i) free-choice dams (H2O + NIC group) drinking from two bottles, containing either nicotine or water; (ii) forced dams (NIC + NIC group) drinking from two bottles, both containing nicotine. We previously demonstrated that nicotine was indeed transferred to the lactating offspring. Regarding behavioural consequences at adolescence, both H2O + NIC and NIC + NIC rats were slower than controls in discovering a novel over a familiar compartment, whilst only NIC + NIC rats exhibited reduced risk-related avoidance and assessment behaviour. Brain analyses at adulthood suggest that, in prefrontal cortex, nicotine per se reduced serotonin, while the maternal overcare reduced CHRN-B2 gene-expression. As a whole, unescapable nicotine-enhanced maternal care could have an impact on the offspring arousal by acting on prefrontal CHRN-B2 gene-expression. When present results are translated to consequences of non-voluntary exposure in humans, we propose that children receiving altered attentions by a smoking caregiver might undergo a neuro-behavioural development biased towards emotional shyness. Highlights: We previously demonstrated that drunk nicotine is indeed transferred to the lactating offspring. Compared to free-choice, forced nicotine drinking by dams (NIC + NIC) elevates maternal care. At adolescence, only NIC + NIC offspring rats exhibited a reduced risk-assessment in the EPM. In prefrontal cortex, nicotine-induced maternal overcare reduced CHRN-B2 gene-expression.