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排序方式: 共有1939条查询结果,搜索用时 31 毫秒
991.
Somatostatin augments the M-current in hippocampal neurons 总被引:13,自引:0,他引:13
Immunocytochemical and electrophysiological evidence suggests that somatostatin may be a transmitter in the hippocampus. To characterize the ionic mechanisms underlying somatostatin effects, voltage-clamp and current-clamp studies on single CA1 pyramidal neurons in the hippocampal slice preparation were performed. Both somatostatin-28 and somatostatin-14 elicited a steady outward current and selectively augmented the noninactivating, voltage-dependent outward potassium current known as the M-current. Since the muscarinic cholinergic agonists carbachol and muscarine antagonized this current, these results suggest a reciprocal regulation of the M-current by somatostatin and acetylcholine. 相似文献
992.
Dr. Guthrie and Felis domesticus or: tripping over the cat 总被引:2,自引:0,他引:2
The principal reactions described in Guthrie and Horton's classic learning monograph appear to have been caused by the mere presence of the experimenters. Neither escape nor food reinforcement is necessary for the establishment of such responses. They are species-typical "greeting" reactions, readily elicited by the sight of human observers. 相似文献
993.
994.
995.
Seismic signals recorded from impacts of missiles at the White Sands Missile Range are radically different from the signal recorded from the Apollo 12 lunar module impact. This implies that lunar structure to depths of at least 10 to 20 kilometers is quite different from the typical structure of the earth's crust. Results obtained from this study can be used to predict seismic wave amplitudes from future man-made lunar impacts. Seismic energy and crater dimensions from impacts are compared with measurements from chemical explosions. 相似文献
996.
997.
998.
Strychnine and the inhibition of previous performance 总被引:1,自引:0,他引:1
The injection of strychnine sulfate into rats inhibits a hurdle-crossing response. Hurdle-crossing tends to decrease with increasing strychnine doses. The data are interpreted as being consistent with consolidation theory. 相似文献
999.
RJ Schoelkopf P Wahlgren AA Kozhevnikov P Delsing DE Prober 《Science (New York, N.Y.)》1998,280(5367):1238-1242
A new type of electrometer is described that uses a single-electron transistor (SET) and that allows large operating speeds and extremely high charge sensitivity. The SET readout was accomplished by measuring the damping of a 1.7-gigahertz resonant circuit in which the device is embedded, and in some ways is the electrostatic "dual" of the well-known radio-frequency superconducting quantum interference device. The device is more than two orders of magnitude faster than previous single-electron devices, with a constant gain from dc to greater than 100 megahertz. For a still-unoptimized device, a charge sensitivity of 1.2 x 10(-5) e/hertz was obtained at a frequency of 1.1 megahertz, which is about an order of magnitude better than a typical, 1/f-noise-limited SET, and corresponds to an energy sensitivity (in joules per hertz) of about 41 Planck's over 2pi. 相似文献
1000.
Moore JW 《Science (New York, N.Y.)》1984,224(4644):50-51