State dependent modification for taste and macronutrient sensing in the brain
Thu-S12-002
Presented by: Ou Fu
Taste and nutrition sensings are essential for guiding feeding behaviors. Although the sensory perception for taste or macronutrient in the CNS is suggested to change depending on internal states, the mechanism remains unclear. Here we show that hypothalamus is involved in the modulation for taste or nutrient sensing during hunger.
(1) Hypothalamic taste modification by AgRP neurons in hunger
In brief access test, overnight fasted mice exhibit increased preference for sweet and tolerance for bitter. Similar phenomenon was observed when orexigenic AgRP neurons were activated. Activation of the LH projected AgRP neurons also recapitulated the hunger-induced change. Neural circuit tracing indicates that AgRP neurons project to parts of the Vglut2 neurons in the LH and these neurons send projections to LS and LHb. Pathway-selective chemogenetic inhibition for Vglut2LH projection in the LS only increased preference for sweet taste. By contrast, Vglut2LH projection in the LHb decreased tolerance for aversive taste.
(2) Macronutrient sensing by CRH neurons in hunger
It is reported that fasted mice prefer high carbohydrate diet over high fat diet, which is caused by the activation of CRH neurons in the PVH. Using fiber photometry, we recorded the CRH neural activities during intragastric infusion of glucose or intralipid in fasted mice.Interestingly, glucose infusion acutely supressed CRH neuron. In contrast, intralipid infusion showed a slow inhibition pattern. Furthermore, injection of gut hormone CCK, secreted by introduction of fatty acids, significantly activated CRH neurons. We hypothesize that dintinct macronutrient sensing pattern in CRH neuron may lead to the preference change in hunger.
In summary，we found two distinct hypothalamic neurons contribute to the modifications of taste or nutrition sensing, which could be important for optimizing feeding behavior under energy deficit.
These studies were supported by Japan KAKEN Grants(15H05624, 18H02160, 20K19735).
(1) Hypothalamic taste modification by AgRP neurons in hunger
In brief access test, overnight fasted mice exhibit increased preference for sweet and tolerance for bitter. Similar phenomenon was observed when orexigenic AgRP neurons were activated. Activation of the LH projected AgRP neurons also recapitulated the hunger-induced change. Neural circuit tracing indicates that AgRP neurons project to parts of the Vglut2 neurons in the LH and these neurons send projections to LS and LHb. Pathway-selective chemogenetic inhibition for Vglut2LH projection in the LS only increased preference for sweet taste. By contrast, Vglut2LH projection in the LHb decreased tolerance for aversive taste.
(2) Macronutrient sensing by CRH neurons in hunger
It is reported that fasted mice prefer high carbohydrate diet over high fat diet, which is caused by the activation of CRH neurons in the PVH. Using fiber photometry, we recorded the CRH neural activities during intragastric infusion of glucose or intralipid in fasted mice.Interestingly, glucose infusion acutely supressed CRH neuron. In contrast, intralipid infusion showed a slow inhibition pattern. Furthermore, injection of gut hormone CCK, secreted by introduction of fatty acids, significantly activated CRH neurons. We hypothesize that dintinct macronutrient sensing pattern in CRH neuron may lead to the preference change in hunger.
In summary，we found two distinct hypothalamic neurons contribute to the modifications of taste or nutrition sensing, which could be important for optimizing feeding behavior under energy deficit.
These studies were supported by Japan KAKEN Grants(15H05624, 18H02160, 20K19735).