Protein malnutrition during gestation and early life decreases neuronal size in the medial prefrontal cortex of post-pubertal rats

Association of maternal pre-pregnancy body mass index with resilience and prosociality of the offspring aged 6-7 years old: a population-based cohort study in Japan

The association between maternal pre-pregnancy obesity and child behavior problems has been widely researched, leaving a gap in understanding the positive aspects of children's mental health. The present study aimed to investigate the association between maternal pre-pregnancy body mass index (BMI) and resilience and prosociality among 6-7 year-old children in Japan. A retrospective cohort study was conducted using data from the Adachi Child Health Impact of Living Difficulty (A-CHILD) study, a population-based study in 2017 and 2019 including all first-grade students in public schools in Adachi, Tokyo, Japan (n = 7328, response rate = 84.7%). Resilience and prosociality were measured by the Children's Resilient Coping Scale and the Strength and Difficulties Questionnaire, respectively. Maternal pre-pregnancy weight and height were reported based on the Mother and Child Health Handbook, and BMI was categorized as underweight (BMI < 18.5), normal weight (BMI 18.5-24.9), overweight (BMI 25.0-29.9), and obesity (BMI ≥ 30). Linear regression models were employed to control for covariates. Maternal pre-pregnancy obesity was found to be negatively associated with child resilience (coefficient: - 3.29; 95% CI - 6.42--0.15), while maternal underweight was negatively associated with child prosociality (coefficient: - 0.12; 95% CI - 0.24--0.005) compared to mothers of pre-pregnancy normal BMI. Perinatal factors, such as gestational weight gain, gestational age, and birth weight, did not mediate the association. Our findings suggest that maternal pre-pregnancy obesity is linked to decreased resilience and maternal underweight is linked to decreased prosociality in children aged 6-7 years. Maintaining an appropriate BMI range before pregnancy may be crucial for enhancing resilience and prosociality of offspring.

Impaired social cognition caused by perinatal protein malnutrition evokes neurodevelopmental disorder symptoms and is intergenerationally transmitted

Nutritional inadequacy before birth and during postnatal life can seriously interfere with brain development and lead to persistent deficits in learning and behavior. In this work, we asked if protein malnutrition affects domains of social cognition and if these phenotypes can be transmitted to the next generation. Female mice were fed with a normal or hypoproteic diet during pregnancy and lactation. After weaning, offspring were fed with a standard chow. Social interaction, social recognition memory, and dominance were evaluated in both sexes of F1 offspring and in the subsequent F2 generation. Glucose metabolism in the whole brain was analyzed through preclinical positron emission tomography. Genome-wide transcriptional analysis was performed in the medial prefrontal cortex followed by gene-ontology enrichment analysis. Compared with control animals, malnourished mice exhibited a deficit in social motivation and recognition memory and displayed a dominant phenotype. These altered behaviors, except for dominance, were transmitted to the next generation. Positron emission tomography analysis revealed lower glucose metabolism in the medial prefrontal cortex of F1 malnourished offspring. This brain region showed genome-wide transcriptional dysregulation, including 21 transcripts that overlapped with autism-associated genes. Our study cannot exclude that the lower maternal care provided by mothers exposed to a low-protein diet caused an additional impact on social cognition. Our results showed that maternal protein malnutrition dysregulates gene expression in the medial prefrontal cortex, promoting altered offspring behavior that was intergenerationally transmitted. These results support the hypothesis that early nutritional deficiency represents a risk factor for the emergence of symptoms associated with neurodevelopmental disorders.

Developmental alterations in the transcriptome of three distinct rodent models of schizophrenia

Schizophrenia is a debilitating disorder affecting just under 1% of the population. While the symptoms of this disorder do not appear until late adolescence, pathological alterations likely occur earlier, during development in utero. While there is an increasing literature examining transcriptome alterations in patients, it is not possible to examine the changes in gene expression that occur during development in humans that will develop schizophrenia. Here we utilize three distinct rodent developmental disruption models of schizophrenia to examine potential overlapping alterations in the transcriptome, with a specific focus on markers of interneuron development. Specifically, we administered either methylazoxymethanol acetate (MAM), Polyinosinic:polycytidylic acid (Poly I:C), or chronic protein malnutrition, on GD 17 and examined mRNA expression in the developing hippocampus of the offspring 18 hours later. Here, we report alterations in gene expression that may contribute to the pathophysiology of schizophrenia, including significant alterations in interneuron development and ribosome function.

Aging Endocrine and Metabolic Phenotypes Are Programmed by Mother’s Age at Conception in a Sex-Dependent Fashion in the Rat

Programming of offspring life-course health by maternal nutrition and stress are well studied. At postnatal day 850, we evaluated male and female steroid levels and metabolism in aged offspring of primigravid sister rats bred at 70, 90, 150, or 300 days’ life. At 850 days life, male offspring corticosterone was similar regardless of maternal age. Female corticosterone was highest in offspring of 70- and 300-day mothers. Serum dehydroepiandrosterone:corticosterone was lowest in both sexes of offspring of 70- and 300-day mothers. Male and female fat depots were smaller in offspring of 150- than 70- and 90-day mothers. Insulin, glucose, and homeostatic model assessment were similar in all male offspring but higher in female offspring of 70-day mothers than other ages. We conclude, maternal age affects offspring aging in an offspring sex-dependent manner and merits consideration in designing and interpreting programming studies.

The Role of Zebrafish and Laboratory Rodents in Schizophrenia Research

Schizophrenia is a severe disorder characterized by positive, negative and cognitive symptoms, which are still not fully understood. The development of efficient antipsychotics requires animal models of a strong validity, therefore the aims of the article were to summarize the construct, face and predictive validity of schizophrenia models based on rodents and zebrafish, to compare the advantages and disadvantages of these models, and to propose future directions in schizophrenia modeling and indicate when it is reasonable to combine these models. The advantages of rodent models stem primarily from the high homology between rodent and human physiology, neurochemistry, brain morphology and circuitry. The advantages of zebrafish models stem in the high fecundity, fast development and transparency of the embryo. Disadvantages of both models originate in behavioral repertoires not allowing specific symptoms to be modeled, even when the models are combined. Especially modeling the verbal component of certain positive, negative and cognitive symptoms is currently impossible.

Late-emerging effects of perinatal undernutrition in neuronal limbic structures underlying the maternal response in the rat

Maternal care in the rat is an ancient behavioral response to specific multisensory inputs widely integrated in a complex forebrain, limbic and brain stem network to meet the basic needs of the young. Early undernutrition interferes with the morphofunctional organization of the brain, including maternal circuitry. The late-emerging effects of pre- and neonatal undernutrition on nest building and pup retrieval by lactating Wistar rats were correlated with dendritic arbor and perikaryon measurements (Golgi-Cox) in layer II pyramidal neurons of the anterior cingulate cortex, layer III pyramidal neurons of the medial prefrontal cortex and multipolar basolateral amygdala neurons examined on lactation days 4 and 12. In the underfed group, pregnant F0 dams received different percentages of a balanced diet. After birth, prenatally underfed (F1) pups continued the undernutrition by remaining with a nipple-ligated mother for 12 h. Weaning occurred at 25 days of age, and pups were subsequently provided an ad libitum diet. At 90 days of age, F1 dams were maternally tested. Early underfed dams showed significant reductions in nest building and prolonged retrieval latencies for grasping pups by inappropriate body areas. The behavioral alterations were concurrent with highly significant reductions in the somatic cross-sectional area and perimeter, spine density and dendritic crossings of cingulate cells and medial prefrontal cortical pyramids, as well as smaller effects on amygdala neurons. The anatomical findings suggest different postsynaptic organizations that may affect the neuronal excitability stages for the integration and encoding of cues triggering the altered maternal response components of early underfed dams.