EGL-4/PKG regulates the role of an interneuron in a chemotaxis circuit of C. elegans through mediating integration of sensory signals

Non-Invasive Detection of Tumors by Volatile Organic Compounds in Urine

Cancer is one of the major causes of death, and as it becomes more malignant, it becomes an intractable disease that is difficult to cure completely. Therefore, early detection is important to increase the survival rate. For this reason, testing with blood biomarkers is currently common. However, in order to accurately diagnose early-stage cancer, new biomarkers and diagnostic methods that enable highly accurate diagnosis are needed. This review summarizes recent studies on cancer biomarker detection. In particular, we focus on the analysis of volatile organic compounds (VOCs) in urine and the development of diagnostic methods using olfactory receptors in living organisms. Urinary samples from cancer patients contain a wide variety of VOCs, and the identification of cancer specific compounds is underway. It has also been found that the olfactory sense of organisms can distinguish cancer-specific odors, which may be applicable to cancer diagnosis. We explore the possibility of novel cancer biomarker candidates and novel diagnostic methods.

Positive interaction between ASH and ASK sensory neurons accelerates nociception and inhibits behavioral adaptation

Central and peripheral sensory neurons tightly regulate nociception and avoidance behavior. The peripheral modulation of nociception provides more veridical and instantaneous information for animals to achieve rapid, more fine-tuned and concentrated behavioral responses. In this study, we find that positive interaction between ASH and ASK sensory neurons is essential for the fast-rising phase of ASH Ca²⁺ responses to noxious copper ions and inhibits the adaption of avoiding Cu²⁺. We reveal the underlying neuronal circuit mechanism. ASK accelerates the ASH Ca²⁺ responses by transferring cGMP through gap junctions. ASH excites ASK via a disinhibitory neuronal circuit composed of ASH, AIA, and ASK. Avoidance adaptation depends on the slope rate of the rising phase of ASH Ca²⁺ responses. Thus, in addition to amplitude, sensory kinetics is significant for sensations and behaviors, especially for sensory and behavioral adaptations.

Crosstalk between neurons and glia through G-protein coupled receptors: Insights from Caenorhabditis elegans

The past decades have witnessed a dogmatic shift from glia as supporting cells in the nervous system to their active roles in neurocentric functions. Neurons and glia communicate and show bidirectional responses through tripartite synapses. Studies across species indicate that neurotransmitters released by neurons are perceived by glial receptors, which allow for gliotransmitter release. These gliotransmitters can result in activation of neurons via neuronal GPCR receptors. However, studies of these molecular interactions are in their infancy. Caenorhabditis elegans has a conserved neuron-glia architectural repertoire with molecular and functional resemblance to mammals. Further, glia in C. elegans can be manipulated through ablation and mutations allowing for deciphering of glial dependent processes in vivo at single glial resolutions. Here, we will review recent findings from vertebrate and invertebrate organisms with a focus on how C. elegans can be used to advance our understanding of neuron-glia interactions through GPCRs.