大鼠中缝背核和中央上核内5－HT能神经元生后发育的免疫细胞化学及图像分析研究

本实验采用免疫细胞化学方法,研究了大白鼠中缝背核及中央上核内５－ＨＴ能神经元的生后转折变化,并结合图像分析对中缝中央上核内５－ＨＴ能神经元的生后发育进行了定量研究。结果显示,在生后第１天,中缝背核和中央上核内５－ＨＴ阳性胞体密集排列,突起较短。从Ｐ１到Ｐ３０,中缝背核内,５－ＨＴ阳性胞体密度明显降低,外侧部５－ＨＴ阳性细胞突起的长度显著增加。中缝中央上核内,至Ｐ１０,５－ＨＴ阳性胞体仍密集排列,且胞体增大,至Ｐ３０,细胞排列变得疏松。从Ｐ９０到Ｐ９０,中缝背核和中央上核内阳性细胞的分布及形态无明显变化。统计学处理结果表明,中缝中央上核内５－ＨＴ能胞体数量从Ｐ１到Ｐ３０有显著性增加,从Ｐ３０到Ｐ９０有显著性减少。胞体面积及周长从Ｐ１至Ｐ３０逐渐增加,在Ｐ１０至Ｐ３０阶段增长最快。Ｐ１与Ｐ３０以及Ｐ１与Ｐ９０比较,胞体形状因子显著增加。从Ｐ１至Ｐ３０,中缝中央上核外侧散布的５－ＨＴ阳性细胞逐渐减少,至成年只能偶尔见到,且胞体变得不规则。     

Comparative study on the infection rates of different laboratory strains of Glossina species by Trypanosoma congolense

Teneral Glossina morsitans centralis Machado, G.austeni Newstead, G.palpalis palpalis Robineau-Desvoidy, G.p.gambiensis Vanderplank, G.fuscipes fuscipes Newstead, G.tachinoides Westwood and G.brevipalpis Newstead, from laboratory-bred colonies, were fed at the same time on the flanks of ten goats infected with Trypanosoma congolense Broden isolated in Tanzania or in Nigeria. The seven tsetse species were infected over the range 0.3-49.2%. Survival of both T.congolense isolates was best in G.m.centralis, poorest in G.austeni and the four palpalis group tsetse, with G.brevipalpis intermediate. It is suggested that there are differences in the gut of different laboratory-bred cultures of Glossina Westwood species and subspecies such that T.congolense parasites can survive better in the gut of some than in others and undergo cyclical development to metacyclics in the hypopharynx.     

中央杏仁核,外侧下丘脑／穹窿周围区,室旁核均参与岛皮层升压反应

实验用乌拉坦麻醉、箭毒制动、人工呼吸的大鼠。将谷氨酸注入岛皮层（ＩＮＳ）以及将Ｐ物质（ＳＰ）注入外侧下丘脑／穹窿周围区（ＬＨ／ＰＦ）或室旁核均引起升压反应。ＩＮＳ－升压反应可被杏仁核（ＡＣ）内预先注射普鲁卡因或谷氨酸二乙酯（ＧＤＥＥ,谷氨酸拮抗剂）以及ＬＨ／ＰＦ内注射［Ｄ－Ｐｒｏ＾２,Ｄ－Ｐｈｅ＾７,Ｄ－Ｔｒｐ＾９］－ＳＰ（ＤＰＤＰＤＴ,ＳＰ拮抗剂）明显衰减,但ＬＨ／ＰＦ内ＧＤＥＥ预处理对该反应无     

Serotonin and motor activity

The activity of brain serotonergic neurons in both the pontine-mesencephalic and medullary groups is positively correlated with the level of behavioral arousal and/or the behavioral state. This, in turn, appears to be related to the level of tonic motor activity, especially as manifested in antigravity muscles and other muscle groups associated with gross motor activity. In addition, a subset of serotonergic neurons displaysa further increase in activity in association with repetitive, central pattern generator mediated responses. Accumulating evidence indicates that this relation to motor activity is related both to the co-activation of the sympathetic nervous system and to the modulation of afferent inputs.     

Microscopic anatomy of the eye of the deep-diving Antarctic Weddell seal (Leptonychotes weddellii)

The microscopic anatomy of the eye of the Weddell seal was studied with various light and electron microscopic methods with a view to correlating morphological findings with the biology of this seal which is adapted to the extremes of the Antarctic environment and to extreme diving excursions into the lightless depths of the sea. In the retina an area centralis was found but no fovea centralis. The densely packed photoreceptors consist exclusively of highly differentiated rods, which in primates detect light at low intensity but have rather poor image discrimination. The ganglion cells are relatively scarce, suggesting a high degree of convergence of the light-sensitive cells on the ganglion cells. The pigment epithelium is almost devoid of pigment granules. The extensive tapetum lucidum is about 400-500 microm thick and is composed of about 30 layers of specialized cells. The cornea is 650 (center) to 800-900 (periphery) microm thick. Its structure and glycosaminoglycan histochemistry correspond to that of other mammals. The iridocorneal angle is unusually deep and pervaded by an elaborate trabecular meshwork, which together with a complex canal of Schlemm can be correlated with the ability to absorb large amounts of fluid. The ciliary muscle and its antagonist, the membrane of Bruch, are poorly developed, suggesting relatively poor abilities of accommodation. The combination of a well-developed tapetum lucidum, an unpigmented pigment epithelium, well-developed rods, and a high number of rods converging on only few ganglion cells is obviously an adaptation to an extreme light sensitivity, enabling the animals to make use of the little light available in the deep sea.     

Sexual experience modulates neuronal activity in male Japanese quail

After an initial increase, repeated exposure to a particular stimulus or familiarity with an event results in lower immediate early gene expression levels in relevant brain structures. We predicted that similar effects would occur in Japanese quail after repeated sexual experience within brain areas involved in sexual behavior, namely, the medial preoptic nucleus (POM), the bed nucleus of stria terminalis (BST), and the nucleus taeniae of the amygdala (TnA), an avian homolog of medial amygdala. High experience subjects copulated with a female once on each of 16 consecutive days, whereas low experience subjects were allowed to copulate either once or twice. Control subjects were never exposed to a female. High experience subjects were faster to initiate sexual interaction, performed more cloacal contacts, and completed each cloacal contact faster than low experience subjects. Low experience subjects showed an increase in egr-1 (ZENK) expression, an immediate early gene product used as marker of neural activation in birds, in the areas of interest. In contrast, in high experience animals, egr-1 expression in the POM, BST, and the periaqueductal gray (PAG) was not different than the level of expression in unmated controls. These results show that experience modulates the level of immediate early gene expression in the case of sexual behavior. Our results also indicate that immediate early gene expression in specific brain areas is not necessarily related to behavioral output but depends on the behavioral history of the subjects.     

Selection of susceptible and refractory lines of Glossina morsitans centralis for Trypanosoma congolense infection and their susceptibility to different pathogenic Trypanosoma species

Abstract .In a single generation of selection, two lines of Glossina morsitans centralis were established that differed significantly in susceptibility to Trypanosoma congolense clone IL 1180. Reciprocal crosses demonstrated that susceptibility was a maternally inherited trait. Differences between the lines, to all phases of the trypanosome infection, were maintained for eight generations, whereas differences in susceptibility to midgut infections were maintained for twenty-eight generations. Thereafter, the lines did not differ in susceptibility to Trypanosoma congolense IL 1180. Susceptibility to infections with Trypanosoma congolense IL 1180 was only a weak predictor of susceptibility to T. congolense clones IL 13-E3 and K60/1, as well as clone T. brucei brucei STIB 247-L. However, the susceptible and refractory lines displayed these phenotypes when tested with Trypanosoma vivax, indicating that the factors that affect susceptibility to trypanosomes are expressed both within and outside the midgut.     

A comparison of Glossina morsitans centralis originating from Tanzania and Zambia, with respect to vectorial competence for pathogenic Trypanosoma species, genetic variation and inter-colony fertility

wo laboratory strains of Glossina morsitans centralis originating from different fly-belts (one from Singida, in Tanzania, and the other from Mumbwa, in Zambia) were compared with respect to vectorial competence for pathogenic Trypanosoma species, genetic variation and inter-colony fertility. The vectorial competence of G.m.centralis of Tanzanian origin for Trypanosoma vivax and T.congolense is similar to, whereas for T.brucei brucei it is lower than the colony of Zambian origin. Nevertheless, these two laboratory strains of G.m.centralis showed levels of susceptibility to the three pathogenic Trypanosoma species which were much greater than previously observed in laboratory colonies of other Glossina species. Electrophoresis of fifteen enzymes revealed that the two colonies differ significantly in allele frequencies at only three loci that are relatively close together on one of the autosomes. Hybridization experiments revealed that G.m.centralis from the two fly-belts are consubspecific.     

Feeding behaviour of Glossina pallidipes and g. morsitans centralis on Boran cattle infected with trypanosoma congolense or T. vivax under laboratory conditions

In field studies, tsetse flies (Diptera: Glossinidae) feed more successfully on cattle infected with Trypanosoma congolense Broden (Kinetoplastida: Trypanosomatidae) than on cattle infected with T. vivax Ziemann or uninfected cattle. Here we describe the first laboratory investigation of this phenomenon. In the first experiment, caged Glossina pallidipes Austen were fed for 1 and 5 min on a Boran steer infected with T. congolense clone IL 1180 and on an uninfected steer. Feeding success was recorded in this way five times over several weeks. The same protocol was subsequently used in three additional experiments with the following combinations: G. pallidipes and a steer infected with T. vivax stock IL 3913, G. morsitans centralis Machado and a steer infected with T. congolense, and G. morsitans centralis and a steer infected with T. vivax. The four experiments were replicated once, making eight experiments in total. In three experiments there was increased tsetse feeding success, measured at 1 min, after a steer became infected (T. congolense, two experiments and T. vivax, one experiment). Analysis of all data combined found no significant differences in tsetse feeding success on the different groups of cattle prior to infection, but after infection tsetse feeding success was significantly greater on the infected cattle (P< 0.001). Trypanosoma congolense infection led to a greater increase in tsetse feeding success than T. vivax infection. The increase in feeding success was not related to changes in the level of anaemia, skin surface temperature or parasitaemia. A possible explanation is the effects of trypanosome infection on cutaneous vasodilation and/or blood clotting in infected cattle. When allowed to feed for 5 min, nearly all tsetse engorged successfully and effects of cattle infection on feeding success were not found.