ABSTRACT
High angular resolution images of extragalactic radio sources are being made with the Highly Advanced Laboratory for Communications and Astronomy (HALCA) satellite and ground-based radio telescopes as part of the Very Long Baseline Interferometry (VLBI) Space Observatory Programme (VSOP). VSOP observations at 1.6 and 5 gigahertz of the milli-arc-second-scale structure of radio quasars enable the quasar core size and the corresponding brightness temperature to be determined, and they enable the motions of jet components that are close to the core to be studied. Here, VSOP images of the gamma-ray source 1156+295, the quasar 1548+056, the ultraluminous quasar 0014+813, and the superluminal quasar 0212+735 are presented and discussed.
ABSTRACT
To investigate the effect of gonadotropin releasing hormone (GnRH) on thermoregulatory skin vasomotion, we injected GnRH into various brain regions in both anesthetized and unanesthetized ovariectomized female rats. Local warming of preoptic area (PO) elicited skin vasodilation in anesthetized rats. Injection of 2 microg GnRH into the septal area lowered the threshold hypothalamic temperature for skin vasodilation at least for 2 h. Similar injections of 2 microg GnRH into the lateral ventricle (LV) and PO were ineffective. Although this vasodilative effect was also obtained after the injection of 20 ng GnRH into the septal area, injections of 2 ng GnRH were without effect. Not only injections of 20 ng Antide, a potent GnRH antagonist, but also injections of the mixed solution of 20 ng GnRH and 20 ng Antide were also without effect. In unanesthetized and unrestrained rats at an ambient temperature of 17 degrees C, injections of 20 ng GnRH into the septal area elicited tail vasodilation lasting for 30 minutes, whereas vehicle injections were ineffective. Injections of 20 ng GnRH into LV and PO were also ineffective. These results indicate that GnRH can elicit thermoregulatory skin vasomotion by acting on GnRH receptors in the septal area. This thermoregulatory vasodilative effect of GnRH might be possibly related to the etiology of climacteric hot flush.
Subject(s)
Body Temperature Regulation/drug effects , Brain/physiology , Gonadotropin-Releasing Hormone/pharmacology , Hormone Antagonists/pharmacology , Ovariectomy , Skin/blood supply , Vasodilation/drug effects , Animals , Body Temperature/drug effects , Brain/drug effects , Female , Gonadotropin-Releasing Hormone/administration & dosage , Hypothalamus/drug effects , Hypothalamus/physiology , Microinjections , Oligopeptides/pharmacology , Preoptic Area/physiology , Rats , Rats, Wistar , Skin Temperature/drug effectsABSTRACT
1. A 0.2 m2 area of the trunk skin was denervated and its center was externally cooled or warmed, when central body temperature was lowered. 2. When the denervated skin was cooled, the central body temperature, at which shivering occurred, was significantly higher than with warming of the denervated skin. 3. It is concluded that the difference was caused by temperature signals originating from thermoreceptors in tissue layers underneath the denervated skin.
Subject(s)
Body Temperature Regulation/physiology , Goats/physiology , Skin/innervation , Thermoreceptors/physiology , Animals , Denervation , FemaleSubject(s)
Hypothermia/epidemiology , Accidents , Humans , Hypothermia/etiology , Japan , Surveys and QuestionnairesABSTRACT
1. A combination technique of a telemetric system and a Walter-type analyzer have been used in the rat to allow on-line display of the sleep-waking cycle of a freely-moving animal on three consecutive days. 2. The characteristics of slow-wave sleep can be analyzed completely by this technique. 3. Telemetric recording of the integrated slow wave is a good method that allows faster and accurate scoring of slow waves to measure the length of sleep in freely-moving animals.
