神經(jīng)系統(tǒng)中有多少冗余目前仍是一個(gè)沒有明確答案的問題?,F(xiàn)在,Motojiro Yoshihara及其同事識(shí)別出了一對果蠅腦細(xì)胞,,他們將其稱之為Fdg或“進(jìn)食”神經(jīng)元,其人工激活足以誘導(dǎo)果蠅完整的進(jìn)食運(yùn)動(dòng)程序。僅僅將這兩個(gè)神經(jīng)元抑制或切除就會(huì)消除由糖誘導(dǎo)的進(jìn)食反射,,但只將其中一個(gè)切除則會(huì)導(dǎo)致非對稱的運(yùn)動(dòng)。這項(xiàng)工作揭示了感覺,、代謝和運(yùn)動(dòng)系統(tǒng)的耦合中一個(gè)嚴(yán)重的瓶頸,。(生物谷Bioon.com)
生物谷推薦英文摘要:
Nature doi:10.1038/nature12208
A single pair of interneurons commands the Drosophila feeding motor program
Thomas F. Flood,Shinya Iguchi, Michael Gorczyca,Benjamin White,Kei Ito & Motojiro Yoshihara
Many feeding behaviours are the result of stereotyped, organized sequences of motor patterns. These patterns have been the subject of neuroethological studies, such as electrophysiological characterization of neurons governing prey capture in toads. However, technical limitations have prevented detailed study of the functional role of these neurons, a common problem for vertebrate organisms. Complexities involved in studies of whole-animal behaviour can be resolved in Drosophila, in which remote activation of brain cells by genetic means enables us to examine the nervous system in freely moving animals to identify neurons that govern a specific behaviour, and then to repeatedly target and manipulate these neurons to characterize their function. Here we show neurons that generate the feeding motor program in Drosophila. We carried out an unbiased screen using remote neuronal activation and identified a critical pair of brain cells that induces the entire feeding sequence when activated. These ‘feeding neurons’ (here abbreviated to Fdg neurons for brevity) are also essential for normal feeding as their suppression or ablation eliminates sugar-induced feeding behaviour. Activation of a single Fdg neuron induces asymmetric feeding behaviour and ablation of a single Fdg neuron distorts the sugar-induced feeding behaviour to become asymmetric, indicating the direct role of these neurons in shaping motor-program execution. Furthermore, recording neuronal activity and calcium imaging simultaneously during feeding behaviour reveals that the Fdg neurons respond to food presentation, but only in starved flies. Our results demonstrate that Fdg neurons operate firmly within the sensorimotor watershed, downstream of sensory and metabolic cues and at the top of the feeding motor hierarchy, to execute the decision to feed.