A Gonadotropin-Releasing Hormone-Like Molecule Modulates the Activity of Diverse Central Neurons in a Gastropod Mollusk, Aplysia Californica

In vertebrates, gonadotropin-releasing hormone (GnRH) is a crucial decapeptide that activates the hypothalamic–pituitary–gonadal axis to ensure successful reproduction. Recently, a GnRH-like molecule has been isolated from a gastropod mollusk, Aplysia californica. This GnRH (ap-GnRH) is deduced to be an undecapeptide, and its function remains to be explored. Our previous study demonstrated that ap-GnRH did not stimulate a range of reproductive parameters. Instead, it affected acute behavioral and locomotive changes unrelated to reproduction. In this study, we used electrophysiology and retrograde tracing to further explore the central role of ap-GnRH. Sharp-electrode intracellular recordings revealed that ap-GnRH had diverse effects on central neurons that ranged from excitatory, inhibitory, to the alteration of membrane potential. Unexpectedly, extracellular recordings revealed that ap-GnRH suppressed the onset of electrical afterdischarge in bag cell neurons, suggesting an inhibitory effect on female reproduction. Lastly, using immunocytochemistry coupled with nickel backfill, we demonstrated that some ap-GnRH neurons projected to efferent nerves known to innervate the foot and parapodia, suggesting ap-GnRH may directly modulate the motor output of these peripheral tissues. Overall, our results suggested that in A. californica, ap-GnRH more likely functioned as a central modulator of complex behavior and motor regulation rather than as a conventional reproductive stimulator

Numerical simulation on dense gas dispersion and fire characteristics after liquefied natural gas release

This PhD dissertation mainly studies the prediction, simulation and mitigation methods of the two main hazards in LNG (Liquefied Natural Gas) industry, LNG vapor dense gas dispersion and LNG fire radiation, respectively. For industrial application purpose, integral model and solid flame model of vapor dispersion and fire radiation, respectively are researched and suggested for using. For complicated scenarios or mitigation measures applied, CFD (Computational Fluid Dynamics) models are studies on the two main accidents