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Kamimura, I.

Publications and source records attributed to Kamimura, I..

2 recordsLinked to original sources

Dietary fiber induces a fat preference associated with the gut microbiota

Eating behavior is essential to human health. However, whether future eating behavior is subjected to the conditioning of precedent dietary composition is unknown. This study aimed to investigate the effect of dietary fiber consumption on subsequent nutrient-specific food preferences between palatable high-fat and high-sugar diets and explore its correlation with the gut microbiota. C57BL/6NJcl male mice were subjected to a 2-week dietary intervention and fed either a control (n = 6) or inulin (n = 6) diet. Afterwards, all mice were subjected to a 3-day eating behavioral test to self-select a high-fat or a high-sugar diet. The test diet feed intakes were recorded, and the mices fecal samples were analyzed to evaluate the gut microbiota composition. The inulin mice exhibited a preference for a high-fat diet over a high-sugar diet, associated with distinct gut microbiota compositions profiles between the inulin and control mice. The gut microbiota Bacteroides acidifaciens (99.68%), Bacteroides caecemuris (99.37%), and Bacteroides xylanolyticus (92.28%) positively correlated with a preference for fat. Further studies involving fecal microbiota transplantation and eating behavior-related neurotransmitter analyses may clarify the role of gut microbiota on food preferences. Food preferences induced by dietary intervention are a novel observation, and the gut microbiome may be significantly associated with this preference.

microbiology↗

The oxytocin system regulates tearing

Tears are an exocrine physiological fluid secreted onto the ocular surface from the lacrimal apparatus in all mammals. Limited research has been conducted on the functional neuronal circuitry of tear production. In particular, the neuronal mechanisms of emotional tearing, which is a physiological reaction harmonized with enhanced emotional arousal and assumed to be unique to humans, remain unclear. We identified that the oxytocin neurons in the paraventricular hypothalamus is functionally projected to the oxytocin receptor-expressing neurons in the lacrimation center of the superior salivatory nucleus. Optogenetic activation or inhibition of these neurons and/or receptors can modulate the superior salivatory nucleus dependent tear secretion mediated through oxytocin. Moreover, we identified that maternal behavior, nociceptive behavior stimulation, and aversive memory retrieval are linked to tearing in mice, and that these emotional linked tearing are suppressed by optogenetic inhibition of the corresponding oxytocin system. Thus, tearing could be regulated through functional connections between central oxytocin systems in the paraventricular hypothalamus and the superior salivatory nucleus.

animal behavior and cognition↗