Reversal Of Dopamine System Dysfunction In Response To High-fat Diet

Discussion in 'Articles & Scientific Studies' started by paymanz, May 12, 2016.

  1. paymanz

    paymanz Member

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    Reversal of dopamine system dysfunction in response to high-fat diet. - PubMed - NCBI

    Abstract
    OBJECTIVE:
    To test whether high-fat diet (HFD) decreases dopaminergic tone in reward regions of the brain and evaluate whether these changes reverse after removal of the HFD.

    DESIGN AND METHODS:
    Male and female mice were fed a 60% HFD for 12 weeks. An additional group was evaluated 4 weeks after removal of the HFD. These groups were compared with control fed, age-matched controls. Sucrose and saccharin preference was measured along with mRNA expression of dopamine (DA)-related genes by Real Time-quantitative PCR (RT-qPCR). DA and 3,4-dihydroxyphenylacetic acid (DOPAC) were measured using high-performance liquid chromatography. DNA methylation of the dopamine transporter (DAT) promoter was measured by methylated DNA immunoprecipitation and RT-qPCR.

    RESULTS:
    After chronic HFD, sucrose preference was reduced, and then normalized after removal of the HFD. Decreased expression of DA genes, decreased DA content and alterations in DAT promoter methylation, was observed. Importantly, response to HFD and the persistence of changes depended on sex and brain region.

    CONCLUSIONS:
    These data identify diminished DA tone after early-life chronic HFD with a complex pattern of reversal and persistence that varies by both sex and brain region. Central nervous system changes that did not reverse after HFD withdrawal may contribute to the difficulty in maintaining weight-loss after diet intervention.
     
  2. OP
    paymanz

    paymanz Member

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    A low protein-high carbohydrate diet decreases D2 dopamine receptor density in rat brain. - PubMed - NCBI

    A low protein-high carbohydrate diet decreases D2 dopamine receptor density in rat brain.

    Abstract
    The property of D2 dopamine receptors in the rat brain was evaluated after long-term dietary manipulation. Groups of rats were pair-fed with equicaloric diet containing low protein (8%)-high carbohydrate, high protein (52%)-low carbohydrate and normal protein (20%) for 36 weeks. The low protein-high carbohydrate fed rats exhibited a significant decrease in the density (Bmax) of D2 dopamine receptor in the striatum (28%) and the mesolimbic regions (36%) with no apparent change in the receptor affinity (Kd). These findings suggest that long-term consumption of a low protein-high carbohydrate diet, by decreasing D2 dopamine receptor density, may be an important determinant of central dopaminergic function.
     
  3. Koveras

    Koveras Member

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    Interesting.

    What I'm taking away:

    High fat diet = decreased dopaminergic tone

    High carb diet = possible increased dopaminergic tone

    Meshes well with Beeler's research on tonic dopamine levels - low levels which could be maladaptive in an obesogenic environment.
     
  4. Koveras

    Koveras Member

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    I think this also helps explain why the combination of high fat AND high sugar tends to be especially difficult/damaging ...because you get chronically low tonic dopamine from the high fat and have large phasic dopamine spikes from the high sugar that the delta between tonic and phasic dopamine becomes especially large and behaviour more and more "reward seeking" - at the same time the low tonic dopamine makes you especially inactive.
     
  5. OP
    paymanz

    paymanz Member

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    yea and protein intake is important.

    and i found this one which is somehow opposite, i currently try understand the concept of dopamine receptor density , dopamine transporter,etc.a little bit hard to translate all of this.


    High-fat diet exposure increases dopamine D2 receptor and decreases dopamine transporter receptor binding density in the nucleus accumbens and caud... - PubMed - NCBI
    Abstract

    This experiment examined dopamine D2 receptor and its transporter (DAT) density in mice fed a high-fat or low-fat diet for twenty days as well as fed twenty days of high-fat diet then changed to low-fat diet for one and seven days. Quantitative autoradiography revealed that twenty days of high-fat diet consumption significantly increased D2 receptor and decreased DAT density in the dorsal and ventral parts of the caudal caudate putamen (D2: 32% and 35% respectively, DAT: 33.3% and 28.8% respectively) compared with low-fat diet. High-fat feeding also increased D2 binding in the nucleus accumbens shell (36%). D2 receptor and DAT density remained unchanged following reversal of the diets from high-fat to low-fat diet. The high-fat diet induced increase of D2 receptor and decrease of DAT binding may have occurred due to defensive control over dopaminergic activity in response to a positive energy balance.
     
  6. Koveras

    Koveras Member

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    My understanding is that increased exposure to dopamine / higher dopaminergic tone will cause a downregulation of dopamine receptors. An upregulation of dopamine receptors would tend to indicate lower dopamine / dopaminergic tone.
     
  7. Parsifal

    Parsifal Member

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    Peat said that the receptor thing is a scam?
     
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