為什麼田鼠會墜入愛河?

【簡介】:愛情似乎從來就與科學不沾邊,愛情是感性的,而科學是理性的,這樣兩個不相關的詞卻被放在了一起。那麼究竟什麼是愛情的科學呢?Whydovolesfallinlove/為什麼田鼠會墜入愛河?Thedetailsofwhatisgoingon—thevolestoryasitwere—isafascinatingone.Whenprairi

導語:愛情似乎從來就與科學不沾邊,愛情是感性的,而科學是理性的,這樣兩個不相關的詞卻被放在了一起。那麼究竟什麼是“愛情的科學”呢?

    Why do voles fall in love / 為什麼田鼠會墜入愛河?

    The details of what is going on—the vole story as it were—is a fascinating one. When prairie voles have sex two hormones called oxytocin and vasopressin are released. If the release of these hormones is blocked prairie-voles' sex becomes a fleeting affair like that normally enjoyed by their rakish montane cousins. Conversely if prairie voles are given an injection of the hormones but prevented from having sex they will still form a preference for their chosen partner. In other words researchers can make prairie voles fall in love—or whatever the vole equivalent of this is—with an injection.

    像往常一樣,最讓人著魔的是田鼠愛情故事的進展細節。當草原田鼠性交時,其體內會釋放兩種稱作催產素和抗利尿激素的荷爾蒙。如果這些荷爾蒙的釋放被阻斷,草原田鼠的性生活便成了短暫的豔遇,它們就會像生性放蕩的山區堂兄那樣去盡享受風流韻事。相反,如果給草原田鼠注射以上荷爾蒙,雖然阻止它們性交,它們依然會鍾情於已選擇的伴侶。換句話說,不過就一劑注射,研究者們便能讓草原田鼠落入情網,不管草原田鼠的感覺如何,反正它們會產生與愛相類似的神經反應。

    A clue to what is happening—and how these results might bear on the human condition—was found when this magic juice was given to the montane vole it made no difference. It turns out that the faithful prairie vole has receptors for oxytocin and vasopressin in brain regions associated with reward and reinforcement whereas the montane vole does not. The question is do humans another species in the 3% of allegedly monogamous mammals have brains similar to prairie voles

    研究者找到一條與正在發生情形相關的線索,這一線索與如何使上述結果作用於人類有關。線索的結論是:當把這一魔術般的汁液注入山區田鼠體內,其反應與草原田鼠如出一轍。這就證實了,在忠誠的草原田鼠大腦內,與獎賞與強化相關聯的區域中,具有一種催產素和抗利尿激素的荷爾蒙受體,然而山區田鼠卻沒有。問題是:人類——據稱是3%實行一夫一妻制的哺乳動物中的另一物種,是否也具有和草原田鼠相似的大腦結構?

    To answer that question you need to dig a little deeper. As Larry Young a researcher into social attachment at Emory University in Atlanta Georgia explains the brain has a reward system designed to make voles and people and other animals do what they ought to. Without it they might forget to eat drink and have sex—with disastrous results. That animals continue to do these things is because they make them feel good. And they feel good because of the release of a chemical called dopamine into the brain. Sure enough when a female prairie vole mates there is a 50% increase in the level of dopamine in the reward centre of her brain.

    為對上述疑惑刨根問底,就需要得更深一些。一位來自佐治亞州,亞特蘭大Emory大學,研究社會附屬關係的學者Larry Yong,他對此的解釋是,田鼠(以及人類和其他動物)的大腦內具有一套獎賞系統用以鼓勵它(他)們去做生物應該完成的行為。如若不然,動物將忘記進食,飲水和性行為,從而招致災難性的後果。動物們不斷重複這些行為是因為那使它們感到快樂。這種快感是一種稱作多巴胺的化學物質在大腦中的釋放使然。當雌性草原田鼠交配時,在大腦獎賞系統中樞,多巴胺水準會有50%的上升,而這已完全足夠讓這些女士們產生上面提到的那種快感。3edu教育

    Similarly when a male rat has sex it feels good to him because of the dopamine. He learns that sex is enjoyable and seeks out more of it based on how it happened the first time. But in contrast to the prairie vole at no time do rats learn to associate sex with a particular female. Rats are not monogamous.

    與草原田鼠近似,雄性家鼠性交時,因多巴胺分泌同樣會感到快樂。當它體驗到性讓它感到愉悅,便會參照初次經歷去搜尋更多機會。但與草原田鼠相反,家鼠決不會學習把性與某個特定的雌性個體關聯起來。畢竟家鼠不是一夫一妻制的哺乳動物。

    This is where the vasopressin and oxytocin come in. They are involved in parts of the brain that help to pick out the salient features used to identify individuals. If the gene for oxytocin is knocked out of a mouse before birth that mouse will become a social amnesiac and have no memory of the other mice it meets. The same is true if the vasopressin gene is knocked out.

    抗利尿激素和催產素就是從這裡進入這個科學傳說的。它們參與了大腦一些部分的工作,以説明選出用於辨別個體的顯著特徵。如果在老鼠出生前,DNA中的抗利尿激素基因即被剔除,那只老鼠將會成為一個社會性失憶個體,它也不會對遇到的其他老鼠留下任何印象。如果催產素基因缺損,以上命題同樣成立。

    The salient feature in this case is odour. Rats mice and voles recognise each other by smell. Christie Fowler and her colleagues at Florida State University have found that exposure to the opposite sex generates new nerve cells in the brains of prairie voles—in particular in areas important to olfactory memory. Could it be that prairie voles form an olfactory “image” of their partners—the rodent equivalent of remembering a personality—and this becomes linked with pleasure

    這裡的顯著特徵是氣味。耗子、老鼠和野鼠靠嗅覺區分彼此。Christie Fowler和她的同事在佛羅里達州大學的研究中發現,把草原田鼠暴露給異性可使其大腦產生新的神經細胞——在對嗅覺記憶至關重要的一些區域尤其如此。人類是靠個性特徵來記住某一個人的。那麼草原田鼠會構造一個嗅覺形像去記住伴侶嗎?這與性愉悅是否存在關聯呢?

    Dr Young and his colleagues suggest this idea in an article published last month in the Journal of Comparative Neurology. They argue that prairie voles become addicted to each other through a process of sexual imprinting mediated by odour. Furthermore they suggest that the reward mechanism involved in this addiction has probably evolved in a similar way in other monogamous animals humans included to regulate pair-bonding in them as well.

    Young博士和他的同事在上個月《比較神經學期刊》的文章中提到了這種想法。他們認為草原田鼠通過一個由氣味做媒介的性烙印過程使配偶彼此沉溺于對方。此外,他們還提到,與這彼此沉溺上癮相關的獎賞機制在其他的一夫一妻制動物(包括人類)生理系統中,或許也進化成了相似的方式,以規範他們的配偶聯結關係。

 

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