Study On Disinhibitory Neural Circuitry Regulation And Rapid Cooling Induced Avoidance Behavior In C.Elegans

Temperature is an important environmental stimulus signal that has a strong effect on the physiology and biochemistry of living organisms.Organisms achieve the correct response to temperature stimuli through behavioral or physiological changes.Previous studies have shown that the nervous system takes different circuits and molecules to respond the changes in temperature.With its ingenious neural network structure,ultra-high temperature resolution,and chemotactic behavior toward the culture temperature,Caenorhabditis elegans has become an ideal animal model for studying temperature stimulus inputs and behavioral outputs.The response of nematodes to warming stimuli exhibits a dependency on the stimulating temperature threshold,but the response characteristics of the cooling stimulus and the regulatory mechanisms hidden under this feature have yet to be studied,and how neurons decode rapid cooling stimuli and translate this information into complex behavioral outputs is unclear.In view of the above problems,this study uses a cooling device based on the semiconductor Peltier effect to carry out a study on the response of C.elegans to cooling stimuli,which can achieve cooling at different rates through programmable feedback control circuits.In this study,the molecular and circuit mechanisms of Caenorhabditis elegans in response to cooling stimuli were studied by combining engineering,calcium imaging techniques for genetically encoded calcium indicators,quantitative behavior,optogenetics,chemical genetics,and molecular biology.Our main findings are summarized below:1.ASH neurons are the main sensory neurons that mediate the avoidance of rapid cooling stimuli.2.ASH neurons activate AIB by releasing glutamate acting on an excitatory glutamate receptor GLR-1 on the AIB to achieve rapid cooling stimulation signaling.3.RIM neurons inhibit the reverse behavior induced by rapid cooling,while AIB inhibits RIM neuronal activity by releasing glutamate acting on the glutamate-gated chloride channels AVR-14 on the RIM,thereby reducing inhibition of the reverse behavior induced by rapid cooling,Eventually,it shows a promoting effect on the reverse behavior induced by rapid cooling.This neural circuit,which inhibits the activity of neurons that inhibits reverse behavior,is called a disinhibition circuit,which ultimately achieves a promoting effect on the reverse behavior induced by rapid cooling stimulation.The above results show that the nociceptive neuron ASH can also feel temperature stimulation and show a significant avoidance response to rapid cooling stimulation.Indepth research has found that avoiding this rapid cooling stimulus is achieved by the disinhibition neural circuit.This disinhibitory neural circuit enables the organism to respond quickly to nociceptive stimuli,resulting in a rapid avoidance response.This new discovery in the field of temperature benefits from the application of a multidisciplinary approach.And these results will expand our understanding of the field of temperature perception,and provide a theoretical basis for investigating the mechanism of higher animal’s response to cooling stimuli.