Sucrose consumption is associated with type 2 diabetes, cardiovascular disease, and cognitive deficits. Sucrose intake during pregnancy might have particularly prominent effects on metabolic, endocrine, and neural physiology. It remains unclear how consumption of sucrose affects parous females, especially in brain circuits that mediate food consumption and reward processing. Here, we examine whether a human-relevant level of sucrose before, during, and after pregnancy (17–18 weeks total) influences metabolic and neuroendocrine physiology in female rats. Females were fed either a control diet or a macronutrient-matched, isocaloric sucrose diet (25% of kcal from sucrose). Metabolically, sucrose impairs glucose tolerance, increases liver lipids, and increases a marker of adipose inflammation, but has no effect on body weight or overall visceral adiposity. Sucrose also decreases corticosterone levels in serum but not in the brain. Sucrose increases progesterone levels in serum and in the brain and increases the brain:serum ratio of progesterone in the mesocorticolimbic system and hypothalamus. These data suggest a dysregulation of systemic and local steroid signalling. Moreover, sucrose decreases tyrosine hydroxylase (TH), a catecholamine-synthetic enzyme, in the medial prefrontal cortex. Finally, sucrose consumption alters the expression pattern of FOSB, a marker of phasic dopamine signalling, in the nucleus accumbens. Overall, chronic consumption of sucrose at a human-relevant level alters metabolism, steroid levels, and brain dopamine signalling in a female rat model.

Corticosterone is produced by the adrenal glands and also produced locally by other organs, such as the brain. Local levels of corticosterone in specific brain regions during development are not known. Here, we microdissected brain tissue and developed a novel liquid chromatography tandem mass spectrometry method (LC‐MS/MS) to measure a panel of seven steroids (including 11‐deoxycorticosterone (DOC), corticosterone, and 11‐dehydrocorticosterone (DHC) in the blood, hippocampus (HPC), cerebral cortex (CC), and hypothalamus (HYP) of mice at postnatal day (PND) 5, 21, and 90. In a second cohort of mice, we measured the expression of three genes that code for steroidogenic enzymes that regulate corticosterone levels (Cyp11b1, Hsd11b1, and Hsd11b2) in the HPC, CC, and HYP. There were region‐specific patterns of steroid levels across development, including higher corticosterone levels in the HPC and HYP than in the blood at PND5. In contrast, corticosterone levels were higher in the blood than in all brain regions at PND21 and PND90. Brain corticosterone levels were not positively correlated with blood corticosterone levels, and correlations across brain regions increased with age. Local corticosterone levels were best predicted by local DOC levels at PND5, but by local DHC levels at PND21 and PND90. Transcripts for the three enzymes were detectable in all samples (with highest expression of Hsd11b1) and showed region‐specific changes with age. These data demonstrate that individual brain regions fine‐tune local levels of corticosterone during early development and that coupling of glucocorticoid levels across regions increases with age.

Attention can be shifted in the direction that another person is looking, but the role played by an observer's mental attribution to the looker is controversial. And whether mental attribution to the looker is sufficient to trigger an attention shift is unknown. The current study introduces a novel paradigm to investigate this latter issue. An actor is presented on video turning his head to the left or right before a target appears, randomly, at the gazed-at or non-gazed at location. Time to detect the target is measured. The standard finding is that target detection is more efficient at the gazed-at than the nongazed-at location, indicating that attention is shifted to the gazed-at location. Critically, in the current study, an actor is wearing two identical masks --one covering his face and the other the back of his head. Thus, after the head turn, participants are presented with the profile of two faces, one looking left and one looking right. For a gaze cuing effect to emerge, participants must attribute a mental state to the actor --as looking through one mask and not the other. Over the course of four experiments we report that when mental attribution is necessary, a shift in social attention does not occur (i.e., mental attribution is not sufficient to produce a social attention effect); and when mental attribution is not necessary, a shift in social attention does occur. Thus, mental attribution is neither sufficient nor necessary for the occurrence of an involuntary shift in social attention. The present findings constrain future models of social attention that wish to link gaze cuing to mental attribution.

Maternal diets can have dramatic effects on the physiology, metabolism, and behaviour of offspring that persist into adulthood. However, the effects of maternal sucrose consumption on offspring remain unclear. Here, female rats were fed either a sucrose diet with a human-relevant level of sucrose (25% of kcal) or a macronutrient-matched, isocaloric control diet before, during, and after pregnancy. After weaning, all offspring were fed a standard low-sucrose rodent chow. We measured indicators of metabolism (weight, adipose, glucose tolerance, liver lipids) during development and adulthood (16-24 wk). We also measured food preference and motivation for sugar rewards in adulthood. Finally, in brain regions regulating these behaviours, we measured steroids and transcripts for steroidogenic enzymes, steroid receptors, and dopamine receptors. In male offspring, maternal sucrose intake decreased body mass and visceral adipose, increased preference for high-sucrose and high-fat diets, increased motivation for sugar rewards, and decreased mRNA levels of Cyp17a1 (an androgenic enzyme) in the nucleus accumbens. In female offspring, maternal sucrose intake increased basal corticosterone levels. These data demonstrate the profound, enduring, diverse, and sex-specific effects of maternal sucrose consumption on offspring phenotype.