Petrosal bones of metatherian mammals from the Late Palaeocene of Itaboraí (Brazil), and a cladistic analysis of petrosal features in metatherians

Metatherian petrosal bones were recovered from the early Late Palaeocene Itaboraí, Brazil, and are formally described. A cladistic analysis of the distribution of 56 petrosal and basicranial characters among extant and fossil metatherians was conducted, resulting in seven parsimonious trees. Relationships among metatherian ingroup taxa are congruent with current understanding of metatherian phylogeny. Metatheria is diagnosed by eight petrosal synapomorphies: stapedial artery absent in adults; reduced, intramural prootic canal; extrabullar internal carotid artery; inferior petrosal sinus between petrosal, basisphenoid, and basioccipital; cava supracochleare and epiptericum completely separated; reduction of the lateral flange; reduction of the anterior lamina; separation of the jugular foramen from the opening for the inferior petrosal sinus. The Palaeocene taxa Mayulestes , Pucadelphy s, and Andinodelphys from Tiupampa, and Petrosal Type II from Itaboraí are the sister groups of all other South American and Australian metatherians. This analysis confirms previous results showing the South American 'monito del monte' Dromiciops nested within the Australasian radiation. Within this australidelphian clade, Dromiciops is closely related to the dasyurids. The South American Caenolestes appears more closely related to the Australidelphia than to the South American didelphids. The Petrosal Types I, III, IV and V from Itaboraí are the stem taxa of the clade Australidelphia plus Caenolestes . The significant synapomorphies supporting this relationship are: enlargement of the fossa subarcuata that produces a bulbous ventral aspect of the mastoid and loss of post-temporal canal.  Journal compilation © 2007 The Linnean Society of London, Zoological Journal of the Linnean Society , 2007, 150 , 85–115. No claim to original French government works.     

Content of chaperon Hsp70 in dopaminergic neurons of the black substance increases in proteasome dysfunstion

In Wistar rats, specific inhibitor UPS lactacystin induced degeneration of 24% of the dopaminergic neurons in the black substance. The work shows that a moderate weakening of the UPS function is characterized by an enhanced activity of the shaperon system. This process seems to restore and maintain population of the dopaminergic neurons.     

Possible mechanisms of unilateral hippocampal insult after bilateral occlusion of common carotid arteries in rats with different types of behavior

Possible mechanisms of unilateral ischemic insults in CA1 region of hippocampus and anterior dorsal nuclei of thalamus after bilateral occlusion of common carotid arteries in rats with different types of behavior are discussed.     

三种绿叶挥发性物质对云南切梢小蠹寄主定位行为的干扰作用

为了研究环境中非寄主阔叶植物释放出的绿叶挥发性物质（GLVs）对针叶树蛀干害虫云南切梢小蠹Tomicus yunnanesis的影响, 选取了(E)-2-己烯醛、 (E)-2-己烯醇和(Z)-3-己烯醇3种释放量较大的绿叶挥发性物质, 通过室内松梢取食试验测试了单组分及两两混合后对云南切梢小蠹寄主定位行为的干扰作用。结果表明： 源于阔叶植物的3种绿叶挥发性物质及其混合物能够不同程度干扰云南切梢小蠹的寄主定位行为。当虫放入广口瓶12 h后, 3个单组分绿叶挥发性物质处理组［A： (E)-2-己烯醛, P＜0.01; B： (E)-2-己烯醇, P＜0.01; C： (Z)-3-己烯醇, P＜0.01］及2个混合组分［D： (E)-2-己烯醛+(E)-2-己烯醇, P＜0.01）; E： (E)-2-己烯醛+(Z)-3-己烯醇, P＜0.01］中滞留在松梢外部的虫数与对照组相比都有显著性差异, 绿叶挥发性物质的存在显著降低了云南切梢小蠹侵害云南松松梢的概率。但是, 24 h后只有D组（P＜0.01）和E组（P＜0.01）滞留在松梢外部的虫数与对照组相比具有显著性差异, 在48 h后只有D组（P＜0.01）与对照相比仍具有显著性差异。本研究为利用非寄主植物的次生代谢产物防治云南切梢小蠹进行了有益的探索。     

Effect of visual deafferentiation on the ultrastructure of synapses of the rat visual cortex.]

Electron microscopic study and quantitative analysis of the visual cortex synapses in 14, 30 and 60-day-old rats were performed after bilateral enucleation of newly-forn rats. A great amount of synapses of other functional systems was shown to be functioning in the area striata in addition to the synapses formed by specific visual afferents. Alterations in the synapses of the area striata of blind rats are developing gradually, achieving the greatest pronouncement in 60-day-old rats. These changes develop according to the type of atrophic process in connection with dysfunction. The atrophic alterations of the synapses were found both in axo-somatic and axo-dendritic synapses on the dendrite trunks and on the thorns. The alterations of synapses being concentrated in layer IV. The quantitative ratio of different kinds of atrophied synapses in the cross-section of the visual cortex was different suggesting the following conclusion about the distribution of the visual afferents. In layers I and III the visual afferents formed mostly axon-thorn contacts and less amount of axo-somatic and axo-dendritic synapses on the dendrite trunks. In layer IV they mainly formed axo-somatic and axo-thorn synapses and less amount of axo-dendritic ones on the dendrite trunks. In layers V and VI they mainly contact with the dendrite trunks and with the nervous cell bodies and more rarely with thorns.     

Interhemispheric asymmetry of the hippocampal damage after bilateral ligation of common carotid arteries

Permanent bilateral occlusion of common carotid arteries in rats with different behaviour types led to non-uniform structural alterations in the hippocampus. In the majority of animals, morphological changes were diffuse (i.e. having no clear localisation in a definite region of the brain structure) and symmetrical (i.e. having no evident prevalence in one of the brain hemispheres). In 6.6% of survived animals, apart from diffuse structural changes, local and asymmetrical sites of lesions occurred in the hippocampus and mostly in the dorso-lateral thalamic nuclei of the right brain hemisphere. These local zones of strongly pronounced pathology corresponded to ischemic insults which were described earlier by other authors under transient cerebral ischemia. It is supposed that the occurrence of unilateral ischemic insults in a definite region of hippocampus and thalamus after bilateral occlusion of common carotid arteries is due to individual features of the anatomy of the vascular brain system which are found more frequently in rats with passive type of behaviour and in rats of the middle group than in rats with active type of behaviour.     

云南切梢小蠹对初侵害云南松挥发物的电生理和行为反应

云南切梢小蠹Tomicus yunnanensis(Kirkendall and Faccoli)是一种蛀害云南松Pinus yunnanensis的本土害虫.为深入了解其寄主选择机制,用顶空动态法和浸提法分别提取了初侵染云南松针叶和松脂的挥发性化合物,并用气相色谱-质谱联用技术(GC-MS)、气相色谱-昆虫触角电位测量系统(GC-EAD)、生测法鉴定和筛选了对云南切梢小蠹具有活性功能的成分.结果表明:云南松针叶和松脂中共有18种化合物,均为萜烯类物质,但两者化学成分的构成有显著差异.针叶中单萜类占99.98％,主要是 α-蒎烯(80.82％)、β-蒎烯(8.78％)、D-柠檬烯(4.77％)、莰烯(2.86％)和β-月桂烯(1.42％),而松脂以单萜类和双萜类为主,前者以α-蒎烯(21.38％)、3-蒈烯(21.42％)和异松油烯(2.78％)为主要成分,后者仅有长叶松酸(51.13％)一种.云南切梢小蠹对α-蒎烯、β-蒎烯、3-蒈烯、γ-萜品烯和4-烯丙基苯甲醚有触角电位反应,其中α-蒎烯、3-蒈烯和γ-萜品烯具引诱作用,4-烯丙基苯甲醚和β-蒎烯则为驱避功能.研究可为开发植物源引诱剂或与性信息素结合进行种群监测和诱杀提供科学依据.