Developmental changes in frontocortical morphology and neurochemistry of neonatal rats following gestational nicotine exposure

Abstract

Exposure of the embryo or foetus to nicotine during development results in some forms of neurological deficits later in life. The current study aimed at determining the effects of prenatal nicotine administration during the 1st and 2nd gestational weeks on the frontal cortex of neonatal Wistar rats. For each week of gestation, pregnant Wistar rats were assigned to 3 groups: a control group (1), and two treated groups (2 and 3), and were given intra-peritoneal nicotine at 6.88 mg/ kg and 13.76 mg/kg doses respectively. The weights of the litters were taken at birth and at postnatal day 4; the whole brain and frontal cortical weights were also assessed. Tissues for histological demonstration were fixed in freshly prepared formol calcium, while specimen for biochemical studies were homogenised and processed for the determination of alkaline phosphatase (ALP) and malondialdehyde (MDA) activities. Findings in the treated animals showed low birth weights, raised ALP but reduced MDA, with corresponding alterations in the cortical cytoarchitecture, which could explain some of the pathological basis for the neurobehavioural problems associated with offspring of women smokers.

Keywords: Prenatal nicotine, Frontal cortex, Morphology, Histology, ALP, MDA