Measures of Alcohol Damagein vitroin the Pigtailed Macaque (Macaca nemestrina)

Cortical gyrification is abnormal in children with prenatal alcohol exposure

OBJECTIVES

Prenatal alcohol exposure (PAE) adversely affects early brain development. Previous studies have shown a wide range of structural and functional abnormalities in children and adolescents with PAE. The current study adds to the existing literature specifically on cortical development by examining cortical gyrification in a large sample of children with PAE compared to controls. Relationships between cortical development and intellectual functioning are also examined.

EXPERIMENTAL DESIGN

Included were 92 children with PAE and 83 controls ages 9-16 from four sites in the Collaborative Initiative on FASD (CIFASD). All PAE participants had documented heavy PAE. All underwent a formal evaluation of physical anomalies and dysmorphic facial features. MRI data were collected using modified matched protocols on three platforms (Siemens, GE, and Philips). Cortical gyrification was examined using a semi-automated procedure.

PRINCIPAL OBSERVATIONS

Whole brain group comparisons using Monte Carlo z-simulation for multiple comparisons showed significantly lower cortical gyrification across a large proportion of the cerebral cortex amongst PAE compared to controls. Whole brain comparisons and ROI based analyses showed strong positive correlations between cortical gyrification and IQ (i.e. less developed cortex was associated with lower IQ).

CONCLUSIONS

Abnormalities in cortical development were seen across the brain in children with PAE compared to controls. Cortical gyrification and IQ were strongly correlated, suggesting that examining mechanisms by which alcohol disrupts cortical formation may yield clinically relevant insights and potential directions for early intervention.

Sexually dimorphic behavioral and brain asymmetries in neonatal rats: effects of prenatal alcohol exposure

Behavioral and neuroanatomical asymmetries were assessed in 3-day-old male and female rat pups chosen from litters whose dams had received one of 3 prenatal treatments: 35% ethanol-derived calories, pair-fed control, or lab chow control. Behavioral laterality was assessed by observing the preferred tail bias on postnatal (PN) day 1. On PN day 3, brains were sectioned and morphometric analyses conducted for total brain volume, left and right neocortical volumes, and left and right hippocampal volumes. Prenatal alcohol exposure altered the population proportions of left, right and neutral tail biases in male pups on PN day 1. Female pups were affected by both prenatal alcohol exposure and maternal undernutrition/stress of pair-feeding. Prenatal alcohol exposure decreased body weight and total brain volume, but increased the brain volume/body weight ratio compared to both control groups. Prenatal alcohol exposure also reduced the volumes of the hippocampus and neocortex, with the greatest proportional reduction found in the volume of the anterior neocortex. A left-right anterior neocortical asymmetry was observed, with tail bias, prenatal treatment and sex all significant factors. Alcohol-exposed males showed a 'feminized' asymmetry. These results demonstrate that a sexually dimorphic cerebral asymmetry can be detected at birth in rats; this asymmetry appears to be related to a postural position bias. The reversal of normal interhemispheric relations by prenatal alcohol exposure in male offspring suggested that the in utero hormonal milieu modulates the development of cerebral lateralization.