Longitudinal MRI of the developing ferret brain reveals regional variations in timing and rate of growth.

Normative ferret brain development was characterized using magnetic resonance imaging. Brain growth was longitudinally monitored in 10 ferrets (equal numbers of males and females) from postnatal day 8 (P8) through P38 in 6-d increments. Template T2-weighted images were constructed at each age, and these were manually segmented into 12 to 14 brain regions. A logistic growth model was used to fit data from whole brain volumes and 8 of the individual regions in both males and females. More protracted growth was found in males, which results in larger brains; however, sex differences were not apparent when results were corrected for body weight. Additionally, surface models of the developing cortical plate were registered to one another using the anatomically-constrained Multimodal Surface Matching algorithm. This, in turn, enabled local logistic growth parameters to be mapped across the cortical surface. A close similarity was observed between surface area expansion timing and previous reports of the transverse neurogenic gradient in ferrets. Regional variation in the extent of surface area expansion and the maximum expansion rate was also revealed. This characterization of normative brain growth over the period of cerebral cortex folding may serve as a reference for ferret studies of brain development.

Consumption habits of pregnant women and implications for developmental biology: a survey of predominantly Hispanic women in California.

BACKGROUND: Healthy post-pregnancy outcomes are contingent upon an informed regimen of prenatal care encouraging healthy maternal consumption habits. In this article, we describe aspects of maternal intake of food, drink, and medication in a population of predominantly Hispanic women in Southern California. Potential implications for unhealthy prenatal dietary choices are discussed. METHODS: The Food, Beverage, and Medication Intake Questionnaire (FBMIQ) measures common practices of maternal consumption during pregnancy. The FBMIQ was administered to English and Spanish speaking pregnant and recently pregnant (36 weeks pregnant - 8 weeks post-partum) women over the age of 18 who were receiving care from a private medical group in Downey CA. RESULTS: A total of 200 women completed the FBMIQ. Consumption habits of healthy foods and beverages, unhealthy foods, unhealthy beverages, and medication are characterized in this article. Data indicate widespread consumption of fresh fruit, meats, milk and juice and indicate most women used prenatal vitamin supplements. Studies in developmental neuroscience have shown that certain substances may cause teratogenic effects on the fetus when ingested by the mother during pregnancy. Those potentially harmful substances included in our study were Bisphenol-A (BPA), methylmercury, caffeine, alcohol and certain medications. Our results show that a proportion of the women surveyed in our study consumed BPA, methylmercury, caffeine, alcohol, and certain medications at varied levels during pregnancy. This represents an interesting finding and suggests a disconnect between scientific data and general recommendations provided to pregnant mothers by obstetricians. CONCLUSIONS: The results of our study demonstrate that a proportion of pregnant women consume substances that are potentially teratogenic and may impact the health and well being of the offspring. It is important to appraise healthy and unhealthy consumption habits in order to encourage healthy practices and alleviate future effects of preventable, toxin-induced developmental issues. Prenatal advising should discourage the consumption of dangerous foods, beverages, and medications that women commonly report eating during pregnancy.

Neuronal Polarization Packs a One-Two Punch.

In this issue of Neuron, Ambrozkiewicz et al. (2018) define a new molecular circuit controlling neuronal polarization and migration through the transcription factor SOX9 to coordinate the production of regulators of both protein synthesis and degradation.

Prenatal nicotine exposure increases anxiety and modifies sensorimotor integration behaviors in adult female mice.

Prenatal exposure to nicotine (PNE) has been associated with a myriad of physiological, cognitive, and behavioral effects in the developing offspring. In this study, CD-1 dams were given injections of nicotine or control vehicle throughout gestation and their offspring were raised to 6 months of age. Adult mice were administered a battery of behavioral tests (the Suok test, the elevated platform test, and the elevated plus maze test) to assess anxiety and sensorimotor integration. PNE resulted in a decreased likelihood of jumping during the elevated platform test and decreased directed exploration in the Suok test, both indicative of increased anxiety. Also, PNE mice showed increased numbers of missteps while traversing an elevated rod in the Suok test, demonstrating altered sensorimotor integration. No significant differences were found in falls, segments traveled, latency to leave the central zone, vegetative responses, risk assessment behaviors, or autogroom behaviors. The elevated plus maze test revealed no significant differences between groups. No significant differences in body and brain weights, or cortical thickness within motor, somatosensory, and visual cortices were observed between PNE and control mice. Although neuroanatomical effects of PNE may be rescued as development progresses, defects in sensorimotor integration and increased anxiety persist into adulthood.

Postnatal effects of prenatal nicotine exposure on body weight, brain size and cortical connectivity in mice.

Maternal smoking results in myriad physical, cognitive, and behavioral effects in offspring due to prenatal exposure to nicotine. As the mammalian neocortex coordinates sensory integration and higher-order processes including cognition and behavioral regulation, it follows that cognitive and behavioral phenotypes of prenatal nicotine exposure (PNE) may correlate with, or stem from changes in anatomy and physiology of the neocortex. The current study uses a prenatal nicotine mouse model to determine effects of PNE on body weight, brain weight, brain length and development of neocortical circuitry, including thalamocortical afferents (TCAs) and intraneocortical connections (INCs). Although dam nutrition, dam weight gain and litter size were not significantly affected by nicotine treatment, PNE resulted in lower newborn birth weight, brain weight and length. Interestingly, the reduction of body weight, brain weight, and brain length observed in newborn PNE mice compared to control mice was no longer present at postnatal day (P) 10. A morphological study of somatosensory and visual TCAs and INCs shows no major defects in areal patterning of these connections. These data add to a growing body of literature on the neurobiological effects of PNE by providing new information on the time course of PNE-related change in the postnatal brain.