被物體刺到產(chǎn)生的疼痛感，和普通接觸帶來的觸碰感,，對成人來說是兩種截然不同的感覺。英國一項最新研究顯示，胎兒要到約9個月即將呱呱墜地前,，才能區(qū)分這兩種感覺。
倫敦大學學院等機構的研究人員在新一期美國《當代生物學》雜志上報告說,，嬰兒出生后要采集血樣,，進行先天性疾病的例行篩檢，采血方法是腳跟皮膚穿刺,。研究人員利用這個機會測量了數(shù)十名嬰兒的腦電圖,。
結果發(fā)現(xiàn)，早產(chǎn)兒對穿刺和普通觸碰時的大腦反應基本相同,，說明他們還不能區(qū)分這兩種感覺,。而足月出生的嬰兒，被穿刺時的腦電圖與接受普通觸碰時的腦電圖截然不同,，這說明他們已經(jīng)能區(qū)分疼痛與普通觸碰的感覺,。
研究人員分析，胎兒大腦在35周到37周時會形成一些重要的神經(jīng)通路,，這之后才會有區(qū)別疼痛的能力,。
參與這次研究的洛倫佐·法布里齊說，“我們從什么時候能夠區(qū)分不同的感覺,，是神經(jīng)發(fā)育研究中的一個基本問題,，本次研究的成果為此提供了線索”。（生物谷 Bioon.com）
doi:10.1016/j.cub.2011.08.010
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A Shift in Sensory Processing that Enables the Developing Human Brain to Discriminate Touch from Pain
.Lorenzo Fabrizi, Rebeccah Slater, Alan Worley, Judith Meek, Stewart Boyd, Sofia Olhede, Maria Fitzgerald
Many persistent pain states (pain lasting for hours, days, or longer) are poorly treated because of the limitations of existing therapies. Analgesics such as nonsteroidal anti-inflammatory drugs and opioids often provide incomplete pain relief and prolonged use results in the development of severe side effects. Identification of the key mediators of various types of pain could improve such therapies. Here, we tested the hypothesis that hitherto unrecognized cytokines and chemokines might act as mediators in inflammatory pain. We used ultraviolet B (UVB) irradiation to induce persistent, abnormal sensitivity to pain in humans and rats. The expression of more than 90 different inflammatory mediators was measured in treated skin at the peak of UVB-induced hypersensitivity with custom-made
