March 23, 2007: 128 (6)
Cover Caption：On the cover: Drosophila projection neurons (PNs) carry odor information to higher olfactory centers. In this image, single PNs from 220 sample brains have been assembled onto a single fly brain model by a process of warping registration, whereby brains of slightly different shapes can be mapped onto one another. On the right, 229 PN axons belonging to 33 glomerular classes are labeled by a class-specific color. Each PN class synapses with specific olfactory receptor neurons and projects to stereotyped regions in the mushroom body calyx and lateral horn (the most lateral structure). The left side shows a subset of PN axons, emphasizing that putative pheromone-representing PNs (red color shades) project their axons to an area of the lateral horn distinct from those that process fruit odors (green color shades). The lateral horn neuropil is therefore compartmentalized to reflect biologically relevant olfactory inputs. For more details, see the article by Jefferis, Potter et al. in this issue (pp. 1187–1203). Cover design is by Christopher Potter and Gregory Jefferis. See also page 1205 of this issue for related work on the mapping of higher-order olfactory information in Drosophila.
生物谷報(bào)道：昆蟲(chóng)的觸角葉(antennal lobe,，AL)作為初級(jí)嗅處理中樞由許多嗅球體(g]onlertli)神經(jīng)網(wǎng)組成,。果蠅中，大約50種嗅感覺(jué)受體神經(jīng)元（olfactory receptor neurons,，ORNs）向AL中50種相應(yīng)的glomeruli發(fā)送軸突,。Uniglomerular投射神經(jīng)元（projection neurons,，PN）將嗅覺(jué)信息傳遞達(dá)蕈狀體（mushroom body，MB）和側(cè)角（lateral horn ,，LH）,。
來(lái)自斯坦福大學(xué)、劍橋大學(xué)和斯坦福研究院的研究人員,，將單細(xì)胞標(biāo)記和圖像配準(zhǔn)（image registration）相結(jié)合,，繪制出高清晰、定量的35條輸入PN通道和幾組LH神經(jīng)元的MB和LH圖譜,。
研究人員發(fā)現(xiàn)：（1）向MB輸入的PN,，與到達(dá)LH的相似；（2）PN的來(lái)自不同sensillar群的ORNs搭擋,，在LH中聚集成簇,；（3）水果的氣味大多被呈遞在后背部LH（posterior-dorsal LH），然而候選信息素應(yīng)答PN 投射到前腹LH（anterior-ventral）,；（4）一個(gè)LH神經(jīng)元的樹(shù)突與特定的PN軸突子集重疊,。這些說(shuō)明LH是根據(jù)嗅覺(jué)輸入的生理價(jià)值進(jìn)行組織的。
果蠅投射神經(jīng)元攜帶嗅覺(jué)信息到達(dá)高級(jí)嗅覺(jué)中樞,。圖中，來(lái)自于220個(gè)樣本腦的特定PNs,，通過(guò)扭曲配準(zhǔn)（warping registration,，生物谷編者譯）過(guò)程被組裝在一個(gè)果蠅大腦模型上。為何外形稍微不同的大腦能夠映射另一個(gè)大腦,？
右邊,，33 組glomerular中的229條PN軸突被一組特定顏色標(biāo)記，每條PN通過(guò)特定的嗅感覺(jué)受體神經(jīng)元對(duì)突觸分類(lèi),，將突觸投射到蕈狀體蕈體冠和側(cè)角（大部分側(cè)面結(jié)構(gòu)）的已定型的區(qū)域,。左邊顯示的是一個(gè)PN軸突子集,，強(qiáng)調(diào)傳遞信息素的PNs（發(fā)紅部分）將它們的軸突投射到側(cè)角的與加工水果氣味的區(qū)域（綠色部分）分開(kāi)的區(qū)域，側(cè)角神經(jīng)毯（neuropil）因此被劃分,，反應(yīng)生物學(xué)相關(guān)的嗅覺(jué)輸入,。
