*Donato A, Kagias K, Zhang Y#, Hilliard MA&.
Neuronal sub-compartmentalization: a strategy to optimize neuronal function. #: Co-first authors. &:Co-senior authors. Biol Rev Camb Philos Soc. [Internet]. 2018;doi:10.1111/brv.12487.
Publisher's VersionAbstractNeurons are highly polarized cells that consist of three main structural and functional domains: a cell body or soma, an axon, and dendrites. These domains contain smaller compartments with essential roles for proper neuronal function, such as the axonal presynaptic boutons and the dendritic postsynaptic spines. The structure and function of these compartments have now been characterized in great detail. Intriguingly, however, in the last decade additional levels of compartmentalization within the axon and the dendrites have been identified, revealing that these structures are much more complex than previously thought. Herein we examine several types of structural and functional sub‐compartmentalization found in neurons of both vertebrates and invertebrates. For example, in mammalian neurons the axonal initial segment functions as a sub‐compartment to initiate the action potential, to select molecules passing into the axon, and to maintain neuronal polarization. Moreover, work in Drosophila melanogaster has shown that two distinct axonal guidance receptors are precisely clustered in adjacent segments of the commissural axons both in vivo and in vitro, suggesting a cell‐intrinsic mechanism underlying the compartmentalized receptor localization. In Caenorhabditis elegans, a subset of interneurons exhibits calcium dynamics that are localized to specific sections of the axon and control the gait of navigation, demonstrating a regulatory role of compartmentalized neuronal activity in behaviour. These findings have led to a number of new questions, which are important for our understanding of neuronal development and function. How are these sub‐compartments established and maintained? What molecular machinery and cellular events are involved? What is their functional significance for the neuron? Here, we reflect on these and other key questions that remain to be addressed in this expanding field of biology.
* Hao Y#, Yang W#, Hall Q, Ren J, Zhang Y&, Kaplan JM&.
Thioredoxin shapes C. elegans sensory response to Pseudomonas produced nitric oxide. #: Co-first authors. &: Co-senior authors. eLife [Internet]. 2018;pii: e36833.
Publisher's VersionAbstractNitric oxide (NO) is released into the air by NO-producing organisms; however, it is unclear if animals utilize NO as a sensory cue. We show that C. elegans avoids Pseudomonas aeruginosa (PA14) in part by detecting PA14-produced NO. PA14 mutants deficient for NO production fail to elicit avoidance and NO donors repel worms. PA14 and NO avoidance are mediated by a chemosensory neuron (ASJ) and these responses require receptor guanylate cyclases and cyclic nucleotide gated ion channels. ASJ exhibits calcium increases at both the onset and removal of NO. These NO-evoked ON and OFF calcium transients are affected by a redox sensing protein, TRX-1/thioredoxin. TRX-1’s trans-nitrosylation activity inhibits the ON transient whereas TRX-1’s de-nitrosylation activity promotes the OFF transient. Thus, C. elegans exploits bacterially produced NO as a cue to mediate avoidance and TRX-1 endows ASJ with a bi-phasic response to NO exposure.
https://doi.org/10.7554/eLife.36833.001 * Liu H, Yang W, Wu T, Duan F, Soucy E, Jin X, Zhang Y.
Cholinergic sensorimotor integration regulates olfactory steering. Neuron [Internet]. 2018;97 (2) :390-405.
Publisher's VersionAbstractSensorimotor integration regulates goal-directedmovements. We study the signaling mechanismsunderlying sensorimotor integration inC.elegansduring olfactory steering, when the sinusoidal move-ments of the worm generate an in-phase oscillation inthe concentration of the sampled odorant. We showthat cholinergic neurotransmission encodes theoscillatory sensory response and the motor state ofhead undulations by acting through an acetylcho-line-gated channel and a muscarinic acetylcholinereceptor, respectively. These signals convergeon two axonal domains of an interneuron RIA,where the sensory-evoked signal suppresses themotor-encoding signal to transform the spatial infor-mation of the odorant into the asymmetry betweenthe axonal activities. The asymmetric synaptic out-puts of the RIA axonal domains generate a direc-tional bias in the locomotory trajectory. Experiencealters the sensorimotor integration to generatespecific behavioral changes. Our study reveals howcholinergic neurotransmission, which can representsensory and motor information in the mammalianbrain, regulates sensorimotor integration duringgoal-directed locomotions.