Differences between trait fear and trait anxiety: Implications for psychopathology

Childhood obesity is associated with increased risk of behavioral/psychological disorders including depression, anxiety, poor learning, and attention deficient disorder. As the majority of women of child-bearing age are overweight or obese and consume a diet high in dietary fat, it is critical to examine the consequences of maternal overnutrition on the development of brain circuitry that regulates offspring behavior. Using a nonhuman primate model of diet-induced obesity, we found that maternal high-fat diet (HFD) consumption caused perturbations in the central serotonergic system of fetal offspring. In addition, female infants from HFD-fed mothers exhibited increased anxiety in response to threatening novel objects. These findings have important clinical implications as they demonstrate that exposure to maternal HFD consumption during gestation, independent of obesity, increases the risk of developing behavioral disorders such as anxiety.

https://www.jneurosci.org/content/jneuro/30/10/3826.full.pdf

Chronic Consumption of a High Fat Diet During Pregnancy Causes Perturbations in the Serotonergic System and Increased Anxiety-like Behavior in Nonhuman Primate Offspring

The macaque radiation is as old as the hominin radiation, approximately 7 million years. After Homo, Macaca has the widest geographical range among primates, and both of these genera are present in tropical and temperate regions as well. Whereas the single extant representative of the genus Homo diverged through processes of cultural diversification, extant species of macaques emerged through processes of evolutionary diversification. Macaque societies are characterized by profound unity and great diversity, and can best be described as variations on the same theme. To understand macaque variation and adaptation, we must take into account the processes that insure the persistence of their societies across generations and environments.

Unity in Diversity: Lessons From Macaque Societies

Recent research with both humans and rhesus monkeys has provided compelling evidence of gene-environment (GxE) interactions throughout development. For example, a specific polymorphism ("short" allele) in the promoter region of the serotonin transporter (5-HTT) gene is associated with deficits in neurobehavioral functioning during infancy and in poor control of aggression and low serotonin metabolism throughout juvenile and adolescent development in monkeys who were reared with peers but not in monkeys who were reared with their mothers and peers during infancy. In contrast, monkeys possessing the "long" allele of the 5-HTT gene exhibit normal neurobehavioral functioning, control of aggression, and serotonin metabolism regardless of their early social rearing history. One interpretation of these GxE interaction data is that the "long" 5-HTT allele somehow confers resiliency to adverse early attachment relationships on those individuals who carry it ("good genes"). An alternative interpretation of the same data is that secure attachment relationships somehow confer resiliency to individuals who carry alleles that may otherwise increase their risk for adverse developmental outcomes ("maternal buffering"). These two interpretations are not mutually exclusive, but the difference in their respective implications for developing prevention and even intervention strategies is considerable. Moreover, the allelic variation seen in certain genes in rhesus monkeys and humans but apparently not in other primate species may actually contribute to their remarkable adaptability and resilience at the species level.

Kris Coleman

Papers

Heritability of fearful-anxious endophenotypes in infant rhesus macaques: a preliminary report