據(jù)8月7日的《科學(xué)》雜志報(bào)道說(shuō),，科學(xué)家們已經(jīng)查明了小鼠體內(nèi)的一組對(duì)瘙癢刺激進(jìn)行反應(yīng)的神經(jīng)元,，改組神經(jīng)元會(huì)通知腦部現(xiàn)在是開(kāi)始瘙抓的時(shí)侯了。 這些發(fā)現(xiàn)本身也撓到了神經(jīng)科學(xué)的一個(gè)長(zhǎng)期的癢處：即神經(jīng)系統(tǒng)是否對(duì)痛覺(jué)和瘙癢的感覺(jué)以同樣的方式進(jìn)行處置。
研究人員對(duì)瘙癢是否基本上不過(guò)是疼痛的一種形式或體內(nèi)是否有專(zhuān)門(mén)的瘙癢、疼痛及其它感覺(jué)（即所謂的“標(biāo)示線(xiàn)路假設(shè)”）的神經(jīng)通路進(jìn)行過(guò)辯論,。 迄今為止，有關(guān)這一假說(shuō)的證據(jù)仍然不甚一致,，但由Yan-Gang Sun所做的一項(xiàng)新的研究應(yīng)該有助于息止這一爭(zhēng)議,。 研究人員過(guò)去曾經(jīng)確認(rèn)了一種叫做GRPR的神經(jīng)元受體是感受瘙癢刺激但卻不感受疼痛刺激的受體。
現(xiàn)在,，這些研究人員證明,，那些脊髓中缺乏GRPR受體神經(jīng)元的小鼠不會(huì)對(duì)瘙癢刺激進(jìn)行撓抓反應(yīng)，但它們感受疼痛的能力則與正常小鼠一樣,。 這類(lèi)表達(dá)GRPR的神經(jīng)元結(jié)果發(fā)現(xiàn)與另外一組叫做SST的神經(jīng)元是不同的,，而這曾經(jīng)是人們過(guò)去爭(zhēng)辯的焦點(diǎn)。 這些新的發(fā)現(xiàn)因而提示,，表達(dá)GRPR的神經(jīng)元是一個(gè)人們長(zhǎng)期以來(lái)尋找的脊髓中的瘙癢感覺(jué)“標(biāo)示線(xiàn)路”的組成成分,。（生物谷Bioon.com）
生物谷推薦原始出處：
Science DOI: 10.1126/science.1174868
Cellular Basis of Itch Sensation
Yan-Gang Sun 1, Zhong-Qiu Zhao 1, Xiu-Li Meng 2, Jun Yin 1, Xian-Yu Liu 1, Zhou-Feng Chen 1*
1 Departments of Anesthesiology, Psychiatry, and Developmental Biology, Washington University School of Medicine Pain Center, St. Louis, MO 63110, USA.
2 Departments of Anesthesiology, Psychiatry, and Developmental Biology, Washington University School of Medicine Pain Center, St. Louis, MO 63110, USA.; Department of Anesthesiology, Peking University Third Hospital, Beijing 100191, P.R. China.
Itch and pain are two distinct sensations. Although our previous study suggested that gastrin-releasing peptide receptor (GRPR) is an itch-specific gene in the spinal cord, a long-standing question of whether there are separate neuronal pathways for itch and pain remains unsettled. Here, we selectively ablated lamina I neurons expressing GRPR in the spinal cord of mice. These mice showed profound scratching deficits in response to all of the itching (pruritogenic) stimuli tested, irrespective of their histamine-dependence. In contrast, pain behaviors were unaffected. Our data also suggest that GRPR+ neurons are different from the spinothalamic tract (STT) neurons that have been the focus of the debate. Together, the present study suggests that GRPR+ neurons constitute a long-sought labeled line for itch sensation in the spinal cord.
