在《科學(xué)》雜志上的一篇研究中，研究者們描述了青春期時(shí)人體內(nèi)細(xì)胞和分子的改變，正是這種改變促使這段時(shí)期的人們智力水平低下。

Ah, puberty. A time for raging hormones, growing independence and being stupid. Okay, not every teenager gets stupid. But they actually do learn less. And in a study published in the journal Science [see Hui Shen et al, http://bit.ly/dbeLY6], researchers describe the cellular and molecular changes that drive this puberty-associated desmartification.

Learning happens in the hippocampus, a brain region that plays a key role in acquiring memories. From a cellular perspective, learning takes place when the connections between nerve cells are strengthened. Interfere with those stronger neuronal connections, and a brain can have trouble laying down new memories. Which, apparently, is what happens in adolescence. At least in mice.

Scientists used a variety of methods to study the brains of pubescent female mice. And they discovered that a particular protein, a kind of GABA receptor, for those of you keeping score at home, crops up in the hippocampus during puberty. These receptor proteins interfere with neuron communication and thus prevent the sort of synaptic strengthening these young animals need to learn.

The good news: a hormone that quiets this pubescent protein turns these young animals back into better learners again. Imagine, a hormone that actually makes an adolescent act smarter.

—Karen Hopkin

啊，青春期！一個(gè)荷爾蒙串升的時(shí)期，一個(gè)增強(qiáng)獨(dú)立性和變笨的時(shí)期。另?yè)?dān)心，當(dāng)然不是每個(gè)青少年都會(huì)變笨。但是他們確實(shí)在那個(gè)時(shí)期降低了認(rèn)知水平。并且，在《科學(xué)》雜志上的一篇研究中，研究者們描述了青春期時(shí)人體內(nèi)細(xì)胞和分子的改變，正是這種改變促使這段時(shí)期的人們智力水平低下。

認(rèn)知開(kāi)始于海馬體，它是大腦中的一個(gè)區(qū)域，對(duì)人類(lèi)獲取知識(shí)有著十分重要的作用。從細(xì)胞的角度來(lái)說(shuō)，當(dāng)神經(jīng)細(xì)胞之間的連接加強(qiáng)時(shí)，認(rèn)知便開(kāi)始了。如果阻斷這些強(qiáng)烈的連接，大腦就不能記憶新知識(shí)了。很明顯，青春期正是有著這樣的現(xiàn)象。至少在老鼠中極為普遍。

科學(xué)家們使用了許多方法來(lái)研究思春期雌性鼠類(lèi)的大腦。他們意外地在處于青春期的海馬體中發(fā)現(xiàn)了一種特殊的蛋白質(zhì)，它是一種GABA （伽馬氨基丁酸）受體（正是它讓一些青少年在家里不敢說(shuō)出自己的真實(shí)成績(jī)）。這些受體蛋白質(zhì)會(huì)干擾神經(jīng)元之間的連接，從而阻礙染色體提高年青動(dòng)物的認(rèn)知能力。

令人欣慰的是，荷爾蒙會(huì)減輕這種蛋白質(zhì)的作用，從而讓這些年青的動(dòng)物回到更好的學(xué)習(xí)狀態(tài)。這么說(shuō)，荷爾蒙事實(shí)上會(huì)讓青少年更加聰明哦！