Interaction between the effects of centrally administered arecoline and leucocyte pyrogen on the activity of posterior hypothalamic neurons in the rabbit

Summary In experiments with urethane-anesthetized rabbits, the alteration in the activity of posterior hypothalamic neurons resulting from intracerebroventricular injection of leucocyte pyrogen was attentuated by subsequent administration of arecoline. Atropine failed to alter the neuronal response to leucocyte pyrogen but abolished the effect of arecoline. The neuronal response to arecoline was reversed in the absence of leucocyte pyrogen.     

ATP is a mediator of chemosensory transduction in the central nervous system

Extracellular signalling by the purine nucleotide ATP has long been associated with sensory function. In the periphery, ATP mediates nociception, mechanosensitivity, thermal sensitivity and O2 chemosensitivity. These processes share a common mechanism that involves the release of ATP to excite afferent fibres via activation of ionotropic P2X and/or metabotropic P2Y receptors. Chemosensors located in the brainstem are crucial for the maintenance of physiological levels of blood gases through the regulation of breathing. Here we show that an increase in pCO2 in the arterial blood triggers the immediate release of ATP from three chemosensitive regions located on the ventral surface of the medulla oblongata. Blockade of ATP receptors at these sites diminishes the chemosensory control of breathing, suggesting that ATP release constitutes a key step in central chemosensory transduction. These new data suggest that ATP, a phylogenetically ancient, unique and simple molecule, has been widely used in the evolution of afferent systems to mediate distinct forms of sensory transduction not only in the periphery but also within the central nervous system.     

Local Structure of Ge／SI（100） Self—Assembled Quantum Dots

Ｔｈｅｌａｔｔｉｃｅｍｉｓｍａｔｃｈｂｅｔｗｅｅｎｔｈｅｓｕｂｓｔｒａｔｅａｎｄｔｈｅｏｖｅｒｇｒｏｗｎｌａｙｅｒａｌｌｏｗｓｔｈｅｆｏｒｍａｔｉｏｎｏｆｓｅｌｆ ａｓ ｓｅｍｂｌｅｄｑｕａｎｔｕｍｄｏｔｓ (ＱＤｓ)ｔｈｒｏｕｇｈｔｈｅＳｔｒａｎｓｋｉ Ｋｒａｓｔａｎｏｖｍｅｃｈａｎｉｓｍ[1,2 ] .Ｔｈｉｓｔｅｃｈｎｉｑｕｅｈａｓｂｅｅｎｓｕｃｃｅｓｓｆｕｌｌｙａｐｐｌｉｅｄｔｏｖａｒｉｏｕｓｓｅｍｉｃｏｎｄｕｃｔｏｒｓｙｓｔｅｍｓ,ａｎｄｉｎｐａｒｔｉｃｕｌａｒｔｏＧｅ/Ｓｉｑｕａｎｔｕｍｄｏｔｓ(Ｑ…     

Interaction between the effects of centrally administered arecoline and leucocyte pyrogen on the activity of posterior hypothalamic neurons in the rabbit

In experiments with urethane-anesthetized rabbits, the alteration in the activity of posterior hypothalamic neurons resulting from intracerebroventricular injection of leucocyte pyrogen was attenuated by subsequent administration of arecoline. Atropine failed to alter the neuronal response to leucocyte pyrogen but abolished the effect of arecoline. The neuronal response to arecoline was reversed in the absence of leucocyte pyrogen.