New Study Reveals the Cause of Sensory Changes in Starved State

A research team led by Professor Kyuhyung Kim at the Department of Brain and Cognitive Sciences has confirmed the mechanism of behavioral changes when an animal feels starved or fed.

Animals in a starved condition gets more sensitive sensory organs that the frequency of certain behaviors such as looking for food, which facilitates survival change. Although feeding state of feeling starved or fed is an important factor causing animals’ behavioral change, but which neurotransmitter among sensory organs has not been known in detail yet.

Professor Kim’s team used Caenorhabditis elegans which has relatively simple nervous systems and confirmed neural circuit structure. By applying the avoidance behavior of Caenorhabditis elegans when it detects certain pheromone, the research team succeeded in clarifying the mechanism of certain behavioral change by the fed and starved condition.

The research team first discovered that the pheromone avoidance behavior of Caenorhabditis elegans increase in a starved condition. At the same time, the team found out that ‘insulin receptor’ adjusts the amount of neurotransmitter delivered to the lower association neurons from sensory neurons that detect pheromone, increasing the avoidance behavior. 

Furthermore, the researchers identified that insulin-like peptide in nematode is released from the intestine of Caenorhabditis elegans, controlling the insulin-like receptor function of pheromone sensing neuron. The team also verified that the amount of insulin-like peptide secretion is adjusted depending on the starved condition and influence animals’ behavioral changes.

By applying the results that insulin secretion controls the synaptic transmission of sensory neurons, it will take a step further towards clarifying the causes and treatment of sensory organ abnormality discovered in the initial stage of insulin-related metabolic syndrome patients such as diabetes.

Professor Kyuhyung Kim said “Feeding state influence the different sensory organs of animals and induces behavioral changes, but its exact mechanism has not been clarified yet. This research was a great opportunity to find out how the interactions between animals’ feeding state and sensory neurons increase animals’ survival chance.”

This study has been published on August 1 in The EMBO Journal, a world-renowned journal in life science, and was jointly participated by Dr. Leesun Ryu of DGIST Brain and Cognitive Sciences as the first author and Dr. Yang Hoon Huh’s research team in Electron Microscope at the Korea Basic Science Institute.

The research was carried out with the support of DGIST’s aging neuron regenerative process project, Basic Research Lab at the National Research Foundation of Korea, Cerebral Cortex Project at the Korea Institute of Brain Science, and the Analysis and Technology R&D from the Korea Basic Science Institute.