Судалгаанд өөх тос ихтэй хоол идсэн залуу эм хулганын тархины холбоос бэхжих чадвар нэмэгдсэн ч үр дүнг хүний ой тогтоолтод хамааруулах боломжгүй.
Scientific Reports сэтгүүлд нийтлэгдсэн судалгаанд өсвөр наснаас залуу насанд шилжих үедээ байсан 31 эм хулганыг таван долоо хоног ажиглажээ. Тэдний 16 нь илчлэгийнхээ 58 хувийг өөх тосноос авдаг хоол, 15 нь 11 хувийг өөх тосноос авдаг хяналтын хоол хэрэглэсэн байна. Мөн омега-6 ба омега-3 тосны хүчлийн харьцаа бүлгүүдэд ялгаатай байсан тул өөх тосны хэмжээ, найрлагын нөлөөг тусад нь тогтоох боломжгүй байв.
Хоёр дахь долоо хоногоос өөх тос ихтэй хоол идсэн хулганууд илүү жин нэмж, энергийн тэнцвэрийг зохицуулах лептин даавар нь нэмэгдэж, өөх тос, сахарын боловсруулалтад оролцдог адипонектин буурчээ. Харин үрэвслийн 21 үзүүлэлтэд бүлгүүдийн хооронд ялгаа гараагүй. Автомат бүртгэлтэй IntelliCage орчинд хулгануудыг нэг буланд байрлах усны савыг олж сурах, дараа нь эсрэг булан руу шилжүүлэх даалгаварт оруулахад өөх тос ихтэй бүлэг хуучин буландаа хяналтын бүлгээс цөөн очсон байна.
Судлаачид бүлэг тус бүрийн таван хулганы гиппокампын эдэд цахилгаан өдөөлт өгч, мэдрэлийн эсийн холбоосын хариу үйлдлийг хэмжжээ. Өдөөлтөөс 40 минутын дараа дохио дамжуулалт өөх тос ихтэй бүлэгт суурь түвшнээс ойролцоогоор 55 хувь, хяналтын бүлэгт 28 хувь өндөр байсан нь урт хугацааны потенциаци буюу холбоос бэхжих чадварын нэг хэмжүүр юм. Генийн идэвхжлийн урьдчилсан шинжилгээгээр эсийн гаднах матриц, түүний дотор коллагентай холбоотой уургийн сүлжээ ажиглагдсан ч олон мянган генийг шалгасны дараа ялгаа статистикийн ач холбогдолгүй болжээ.
Үр дүнг болгоомжтой тайлбарлах шаардлагатай: зан үйлийн шинжилгээнд урьдчилан тогтоосон шалгуураар хасалт хийсний дараа хяналтын зургаа, өөх тос ихтэй бүлгийн 10 хулгана хамрагдсан бөгөөд шинэ зөв буланд очсон тоонд мэдэгдэхүйц ялгаа гараагүй. Мөн хуучин буланд цөөн очсон нь сурсан зан үйлээ орхих чадвар сайжирсныг дангаараа батлахгүй, тархины холбоосын өөрчлөлт зан үйлийн ялгааг үүсгэсэн эсэх ч тодорхойгүй байна. Бүлэг бүр нэг IntelliCage-д байрласан, бичлэгийг гиппокампын орон зайн суралцахтай харьцангуй бага холбоотой доод хэсгээс авсан бөгөөд хоёр хэсэг хамтран ажилладаг. Судалгаа хүний ой тогтоолтод ашиг тустайг эсвэл нөлөө хэр удаан үргэлжлэхийг тогтоогоогүй; кетоны солилцооны боломжит нөлөөг мөн шалгаагүй бөгөөд өөх тос, сахар ихтэй хооллолтыг удаан хугацааны ой санамжийн асуудалтай холбосон өмнөх мэрэгчийн судалгаанууд бий.
Дэлгэрэнгүйг эх сурвалжаас харах
↓Эх сурвалжийг нээх ↓
Fatty foods aren’t something we usually associate with a more adaptable brain. Much of the research on diet and learning explores how unhealthy eating can cause difficulties. But the brain may start adapting before those problems appear.
Learning depends partly on nerve cells changing their connections. That flexibility helps an animal remember a place or abandon a familiar route. Scientists wanted to understand what happens to this ability when a young animal starts eating a high-fat diet.
In young female mice, they found an unexpected response: Connections in a memory-related brain region showed a greater capacity to strengthen. The animals also seemed better at dropping a learned behavior that no longer worked.
Thestudy, published inScientific Reports, followed 31 mice through five weeks spanning adolescence and young adulthood, while brain circuits were still developing.
Researchers at Italy’s Istituto Superiore di Sanità and Sapienza University of Rome chose females to explore their reported vulnerability to metabolic and mental health problems occurring together.
However, an earlier study found that some inflammatory and metabolic changes seen in adult males after short-term high-fat feeding did not occur in females.
How would younger females’ still-developing brains respond?
Sixteen mice received food supplying 58 percent of its calories from fat, largely from coconut and safflower oils. Fifteen ate a control diet supplying 11 percent.
The foods also differed in two families of dietary fats, omega-6s and omega-3s. Their ratio was 120 to 1 in the high-fat diet, compared with 7 to 1 in controls. Both fat quantity and composition changed, so the experiment couldn’t isolate their individual effects.
From the second week onward, the high-fat group gained more weight. Blood tests also revealed changes in two hormones that help regulate the body’s energy balance.
Leptin, which tells the brain about fat stores, increased, while adiponectin, which helps the body process sugars and fats, decreased. None of the 21 detectable blood markers of inflammation differed between groups.
To track behavior, the team used IntelliCage, an automated housing system where identification chips and sensors recorded individual mice’s visits to drinking stations.
During the learning test, drinking bottles were accessible in just one of four corners. Both groups learned where to go. Then access moved to the opposite corner.
The high-fat group returned to the old corner less often than controls, suggesting they more readily abandoned what they had learned.
The team also examined brain slices from five mice per group, measuring how nerve-cell connections responded to electrical stimulation in a region involved in learning and memory, the hippocampus.
Forty minutes after stimulation, signal transmission was approximately 55 percent above baseline in the high-fat group, compared with 28 percent in controls. This lasting strengthening, called long-term potentiation, is one measure of the brain’s ability to change its connections.
The scientists suggest this added flexibility could help preserve learning early in dietary exposure, even while metabolic changes are underway.
Gene activity offered a possible clue: Exploratory analyses pointed toward a network of proteins, including collagen, that surrounds brain cells and helps organize their connections. However, none of the individual gene differences remained statistically significant after correction for testing thousands of genes.
The behavioral results also require care. The learning analysis included six control mice and 10 high-fat mice after exclusions under predefined criteria, including insufficient visits.
The high-fat group reached above-chance performance earlier, but that timing alone doesn’t demonstrate a difference between groups. After the switch, visits to the new correct corner did not differ significantly.
The experiment didn’t show that stronger connections caused the behavioral differences. The electrical recordings also came from the lower part of the hippocampus. Learning where places are is more closely associated with its upper part, although the two work together.
Other mechanisms remain possible. The scientists note that some fats in the diet could alter the production or use of ketones, substances the brain can use for fuel. That possibility wasn’t tested here.
Other rodent research has linked fatty, sugary diets to lasting memory problems. These findings don’t establish a human memory benefit or reveal how long the effect lasts.
Each diet group also occupied one IntelliCage, so differences between cages or social groups could have contributed to the findings.
Repeating the experiment across more cages, including males, and following animals longer could reveal whether the increased flexibility persists and whether learning eventually becomes impaired.
The research has been published in Scientific Reports.
This article was fact-checked by Fiona MacDonald and edited by Fiona MacDonald. While we pride ourselves on our process, we are only human. If you spot a mistake, please let us know.
