Optical Control of Cell Signaling with Red/Far-Red Light-Responsive Optogenetic Tools in .

Optogenetic techniques have been intensively applied to the nematode to investigate its neural functions. However, as most of these optogenetics are responsive to blue light and the animal exhibits avoidance behavior to blue light, the application of optogenetic tools responsive to longer wavelength light has been eagerly anticipated. In this study, we report the implementation in of a phytochrome-based optogenetic tool that responds to red/near-infrared light and manipulates cell signaling.

OFF-responses of interneurons optimize avoidance behaviors depending on stimulus strength via electrical synapses.

Optimization of the types and timing of avoidance behaviors depending on the intensity of a noxious stimulus is essential for survival; however, processing in the central nervous system and its developmental basis are largely unknown. Here, we report that Caenorhabditis elegans preferentially selects one of three different types of avoidance behaviors depending on the strength of the noxious stimulus. We screened 210 neuronal transcription factors using a combination of optogenetics and RNA interference methods and identified 19 candidates required for avoidance behaviors.

Efficient synthesis of phycocyanobilin in mammalian cells for optogenetic control of cell signaling.

Optogenetics is a powerful tool to precisely manipulate cell signaling in space and time. For example, protein activity can be regulated by several light-induced dimerization (LID) systems. Among them, the phytochrome B (PhyB)-phytochrome-interacting factor (PIF) system is the only available LID system controlled by red and far-red lights.

Modulation of sensory information processing by a neuroglobin in .

Sensory receptor neurons match their dynamic range to ecologically relevant stimulus intensities. How this tuning is achieved is poorly understood in most receptors. The roundworm avoids 21% O and hypoxia and prefers intermediate O concentrations.

GLOBIN-5-dependent O2 responses are regulated by PDL-1/PrBP that targets prenylated soluble guanylate cyclases to dendritic endings.

Aerobic animals constantly monitor and adapt to changes in O2 levels. The molecular mechanisms involved in sensing O2 are, however, incompletely understood. Previous studies showed that a hexacoordinated globin called GLB-5 tunes the dynamic range of O2-sensing neurons in natural C.

In vivo genetic dissection of O2-evoked cGMP dynamics in a Caenorhabditis elegans gas sensor.

cGMP signaling is widespread in the nervous system. However, it has proved difficult to visualize and genetically probe endogenously evoked cGMP dynamics in neurons in vivo. Here, we combine cGMP and Ca(2+) biosensors to image and dissect a cGMP signaling network in a Caenorhabditis elegans oxygen-sensing neuron.

The temporal pattern of stimulation determines the extent and duration of MAPK activation in a Caenorhabditis elegans sensory neuron.

The Caenorhabditis elegans ASER sensory neuron is excited when environmental NaCl concentration is decreased. The mitogen-activated protein kinase (MAPK) MPK-1, a homolog of ERK (extracellular signal-regulated kinase), is activated during excitation of ASER sensory neurons. We created and expressed a fluorescence resonance energy transfer (FRET)-based MAPK activity probe in ASER neurons and then exposed the worms to various cyclic patterns of stimulation (changes in NaCl concentration) to monitor the dynamics of MPK-1 activity.

Odour concentration-dependent olfactory preference change in C. elegans.

The same odorant can induce attractive or repulsive responses depending on its concentration in various animals including humans. However, little is understood about the neuronal basis of this behavioural phenomenon. Here we show that Caenorhabditis elegans avoids high concentrations of odorants that are attractive at low concentrations.

Neuronal plasticity regulated by the insulin-like signaling pathway underlies salt chemotaxis learning in Caenorhabditis elegans.

Quantification of neuronal plasticity in a living animal is essential for understanding learning and memory. Caenorhabditis elegans shows a chemotactic behavior toward NaCl. However, it learns to avoid NaCl after prolonged exposure to NaCl under starvation conditions, which is called salt chemotaxis learning.

Roles for class IIA phosphatidylinositol transfer protein in neurotransmission and behavioral plasticity at the sensory neuron synapses of Caenorhabditis elegans.

Growing evidence suggests that sensory neuron synapses not merely pass, but actively encode sensory information and convey it to the central nervous system. The chemosensory preferences of Caenorhabditis elegans, as manifested in the direction of chemotaxis, are reversibly regulated by prior experience at the level of sensory neurons; the attractive drive is promoted by diacylglycerol (DAG) signaling, whereas the counteracting repulsive drive requires PtdIns(3,4,5)P(3) signaling. Here we report that the two opposing drives require a class IIA phosphatidylinositol transfer protein (PITP), PITP-1, which localizes to the sensory neuron synapses.