Brain function is associated with the morphologies,organizations,synaptic connections,and circuit activities of neurons.As the building blocks of the brain,neurons display remarkable morphological diversity and form neural circuits with synaptic connections.Understanding the'wiring'connectomes among synapses and their roles in neural networks
WANG HaoYAN YanMIN LuZHU Ling-YunZHANG Dong-YiJIAO Ren-Jie
Body size is one of the features that distinguish one species from another in the biological world. Animals have developed mechanisms to control their body size during normal development. However, how animals cope with genetic alterations and/or environmental stresses to develop into normal-sized adults remain poorly understood. The ability of the animals to develop into a normal-sized adult after the challenges of genetic alterations and/or environmental stresses reveals a robustness of body size control. Here we show that the mutation of dGPAT4, a de novo synthase of lysophosphatidic acid, is a genetic alteration that triggers such a robust response of the animals to body size challenges in Drosophila. Loss of dGPAT4 leads to a severe delay of development, slow growth and resultant small-sized animals during the larval stages, but results in normal-sized adult flies. The robust body size adjustment of the dGPAT4 mutant is likely achieved by corresponding changes in ecdysone and insulin signaling, which is also manifested by compromised food intake. Thus, we propose that a strategy has been evolved by the animals to reach final body size when challenged by genetic alterations, which requires the coordinated ecdysone and insulin signaling.
Yan YanHao WangHanqing ChenAnya Lindstrm-BattleRenjie Jiao
Drosophila melanogaster feeds mainly on rotten fruits, which contain many kinds of sugar. Thus, the sense of sweet taste has evolved to serve as a dominant regulator and driver of feeding behavior. Although several sugar receptors have been described, it remains poorly understood how the sensory input is transformed into an appetitive behavior. Here, we used a neural silencing approach to screen brain circuits, and identified neurons labeled by three Gal4 lines that modulate Drosophila feeding behavior. These three Gal4 lines labeled neurons mainly in the suboesophageal ganglia （SOG）, which is considered to be the fly＇s pri- mary taste center. When we blocked the activity of these neurons, flies decreased their sugar consumption significantly. In contrast, activation of these neurons resulted in enhanced feeding behavior and increased food consumption not only towards sugar, but to an array of food sources. Moreover, upon neuronal activation, the flies demonstrated feeding behavior even in the absence of food, which suggests that neuronal activation can replace food as a stimulus for feeding behavior. These findings indicate that these Gal4-1abeled neurons, which function downstream of sensory neurons and regulate feeding behavior to- wards different food sources is necessary in Drosophila feeding control.
SUN FeiWANG YiJinZHOU YanQiongVAN SWINDEREN BrunoGONG ZheFengLIU Li
