human being across the globe are eating their means into some serious health problems , and our ostensible addiction to sugar is n’t help oneself . But what is repulse many of us to compulsively overgorge ? scientist have known for a foresightful clip that it ’s not just because sweet snacks try out nice , or because we ’re suckers for alluring adverts .
Now , scientists could be closer to understanding these behaviors with the find of a brain circuit that controls determined sugar intake in mice . Interestingly , this reinforcement - related mesh does not govern feeding behaviour necessary for survival , raising hope that targeting it could provide a means for treating compulsive gluttony in humans without impairing healthy eating behavior .
Much like gaming or drug dependence , compulsive overeating is a reward - seek behavior . It is for this rationality that scientists suspected that a population of nous cell connecting the sidelong hypothalamus to the adaxial tegmental orbit could play a role in compulsive gluttony since this region has previously been associated with other reward - related behaviour , such as imbibing and sexual practice .
To find out whether this might be the character , scientist from MIT muster in the avail of a technique called optogenetics . This method acting involves inserting gene for wanton - sensitive proteins into sure cells , allowing scientist to selectively switch on or off distinct populations of Einstein cells using sparkle , which is delivered through an implanted optic fiber .
As describe inCell , when the researchers activated the projection from the sidelong hypothalamus to the adaxial tegmental area in well - fed mice , they set out to spend significantly more clip sticking their nozzle in an area which hand over a sugary kickshaw . They were n’t even dissuade when accessing the reward meant that they had to foil a platform which cave in them a small electric shock . Conversely , switching off this universe of cubicle reduced this sugar - look for demeanour , but did n’t affect normal food usance , suggesting two distinct networks govern these different demeanour .
Interestingly , another recent subject area , which was also published inCell , severally identify populations of brain cells ask in both alimentation and reward - assay behaviour . Once again using optogenetics , researchers from the University of North Carolina aim a clustering of cell within the sidelong hypothalamus of computer mouse . When the cadre were activate , the mice feed more frequently , but when they were switch off , the mice did n’t overeat . Detailed imaging of these cells reveal that distinct populations were active when the mouse received food rewards or when they showed interest group in nutrient .
From an evolutionary perspective , it piddle sense that we have these two disjoined circuits . Long before the advent of New transport and icebox , many sugary food would have only been available at certain times of the year , meaning our ascendant would probably binge on these source of DOE whenever they could . However , when food was in overall short supplying , such as during winter month , it would be necessary to eat whatever is available , but in sensitive sum for ration out what little there was .
“ We have not yet adapt to a world where there is an superabundance of moolah , so these circuits that drive us to satiate ourselves with sweets are now serving to create a unexampled health problem , ” said lead researcher Kay Tye . However , these new discoveries may allow scientist to begin tackle this issue by developing drugs that target these regions .
[ ViaCell , Cell , Cell PressandThe Scientist ]
