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Interneurons, innervated by multiple sensory neurons, need to integrate information from these sensory neurons and respond to sensory stimuli adequately. Mechanisms how sensory information is integrated to form responses of interneurons are not fully understood. In Caenorhabditis elegans, loss-of-function mutations of egl-4, which encodes a cGMP-dependent protein kinase (PKG), cause a defect in chemotaxis to odorants. Our genetic and imaging analyses revealed that the response property of AIY interneuron to an odorant is reversed in the egl-4 mutant, while the responses of two upstream olfactory neurons, AWA and AWC, are largely unchanged. Cell- ablation experiments show that AIY in the egl-4 mutant functions to suppress chemotaxis. Furthermore, the reversal of AIY response occurs only in the presence of sensory signals from both AWA and AWC. These results suggest that sensory signals are inadequately integrated in the egl-4 mutant. We also show that egl-4 expression in AWA and another sensory neuron prevents the reversed AIY response and restores chemotaxis in the egl-4 mutants. We propose that EGL-4/PKG, by suppressing aberrant integration of signals from olfactory neurons, converts the response property of an interneuron to olfactory stimuli and maintains the role of the interneuron in the circuit to execute chemotactic behavior.

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Surgical materials, such as gauze, can be accidentally left inside of patients following surgery. This iatrogenic complication should be avoided and is often prevented by routine X-ray analysis after surgical abdominal procedures. We report a case of retained barium in the appendix that was difficult to distinguish from surgical remnants. A 41-year-old Japanese female was diagnosed with uterine leiomyoma and underwent laparoscopic myomectomy. The postoperative X-ray test showed a cord-like material in the lower right abdomen that was not captured in the preoperative X-ray test two months prior to the operation. Because of this difference, the area was reexamined laparoscopically. After examination, we concluded that the cord-like material in X-ray tests was in fact retained barium in the appendix. Barium can be retained in the appendix for long periods of time, and retained barium in the appendix can be captured radiographically and can mimic the appearance of surgical remnants, appearing as a cord-like material. The knowledge above combined with detailed interviews before surgery could prevent such confusion during interpretation of X-ray tests after surgery.

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INTRODUCTION: Laparoscopic surgery is less invasive than open surgery and is now common in various medical fields. However, laparoscopic surgery is more difficult than open surgery and often requires additional time for the operator to achieve mastery. Therefore, we investigated the use of assistive technology for uniform laparoscopic surgery. METHODS: We used the OpenCV2 library for augmented reality with an ArUco marker to detect and estimate forceps positioning. We used Sense HAT as the gyro sensor. The development platforms used were Mac OS X 10.11.3 and Raspberry Pi 3, model B. RESULTS: By attaching the ArUco marker to the needle holder, we could draw a line vertically to the marker. When the needle was held, a cube could be imagined, and both the needle and lines could be used to determine the appropriate position. By attaching the gyro sensor to the camera, we could detect its angle of rotation. We obtained stabilized images by rotating the image by the detected degrees; this was possible for any camera position. CONCLUSIONS: Assistive technology allowed us to obtain consecutive converted images in real time and may be readily applicable to clinical practice.

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Many animal species change their behavior according to their stage of development. However, the mechanisms involved in translating their developmental stage into the modifications of the neuronal circuits that underlie these behavioral changes remain unknown. Here we show that Caenorhabditis elegans changes its olfactory preferences during development. Larvae exhibit a weak chemotactic response to the food-associated odor diacetyl, whereas adults exhibit a strong response. We show that germline loss, caused either by laser ablation of germline precursor cells or mutations, results in a diacetyl-specific chemotactic defect in adult animals. These results suggest that germline cells, which proliferate dramatically during the larval stages, enhance chemotaxis to diacetyl. Removal experiments of specific neurons suggested that AWA olfactory neurons and their downstream interneurons, AIA and AIB, are required for germline-dependent chemotactic enhancement. Calcium imaging in animals lacking germline cells indicates that the neural responses of AWA and AIB to diacetyl stimuli are decreased compared with animals with an intact germline. These changes in neural activities may at least partly explain the behavioral change of animals lacking germline cells. Furthermore, this germline-dependent chemotactic change depends on the transcription factor DAF-16/FOXO. We find that organismal behavior changes throughout development by integrating information about physiological status from internal tissues to modify a simple sensory circuit.

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The body size of Caenorhabditis elegans is thought to be controlled by sensory inputs because many mutants with sensory cilium structure defects exhibit small body size. The EGL-4 cGMP-dependent protein kinase acts in sensory neurons to reduce body size when animals fail to perceive sensory signals. In addition to body size control, EGL-4 regulates various other behavioral and developmental pathways, including those involved in the regulation of egg laying and chemotaxis behavior. Here we have identified gcy-12, which encodes a receptor-type guanylyl cyclase, as a gene involved in the sensory regulation of body size. Analyses with GFP fusion constructs showed that gcy-12 is expressed in several sensory neurons and localizes to sensory cilia. Genetic analyses indicated that GCY-12 acts upstream of EGL-4 in body size control but does not affect other EGL-4 functions. Our studies indicate that the function of the GCY-12 guanylyl cyclase is to provide cGMP to the EGL-4 cGMP-dependent kinase only for limited tasks including body size regulation. We also found that the PDE-2 cyclic nucleotide phosphodiesterase negatively regulates EGL-4 in controlling body size. Thus, the cGMP level is precisely controlled by GCY-12 and PDE-2 to determine body size through EGL-4, and the defects in the sensory cilium structure may disturb the balanced control of the cGMP level. The large number of guanylyl cyclases encoded in the C. elegans genome suggests that EGL-4 exerts pleiotropic effects by partnering with different guanylyl cyclases for different downstream functions.

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