Progressive atrophy of pyramidal neuron dendrites in autoimmune MRL-lpr mice

The autoimmune-prone MRL-lpr substrain of mice develop an autoimmunity-associated behavioral syndrome (AABS) which resembles in many respects the behavior of animals exposed to chronic stress. The present study examined whether these mice show changes in the morphology of neuronal dendrites, as found in animals exposed to chronic stress. A modified Golgi-Cox procedure was used to visualize the dendrites of pyramidal neurons in the parietal cortex and in the CA1 hippocampal field of 5-week and 14-week old MRL-lpr mice and MRL + / + controls. Reduced dendritic branching and length, and an up to 20% loss of dendritic spines were observed in parietal and hippocampal pyramidal neurons of MRL-lpr mice at both ages. In the parietal cortex, there was an age-dependent potentiation in the reduction of basilar, but not apical, dendrite branching and length, as well as in the loss of spines on basilar segments. Loss of spines in the hippocampus followed an age-related course for apical but not basilar dendrites. Moreover, compared to age-matched controls, brain weight was smaller in MRL-lpr mice at 14 but not 5 weeks of age. Considering that dendritic atrophy becomes more extensive when autoimmune disease is florid in MRL-lpr mice, it is proposed that immune/inflammatory factor(s) produce dendritic loss. Reduced dendritic complexity may represent, at least in part, a structural basis for the altered behavioral profile of MRL-lpr mice.     

Prefrontal cortex and the regulation of food intake in the rat.

Studied the postoperative regulation of food and water intake in a total of 103 male Wistar albino rats with aspiration lesions to either the medial frontal or orbital frontal projection fields of thalamic nucleus medialis dorsalis (prefrontal cortex). These projection fields proved functionally dissociable in that orbital frontal lesions impaired immediate postoperative regulation of food and water intake for up to 2 wks, while medial frontal lesions produced finickiness. Neither lesion affected response to cellular dehydration or recovery from extended deprivation. Data are consistent with data from rhesus monkeys with prefrontal lesions and differ from animals with lateral hypothalamic lesions. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Studies on the activity, properties and isoenzymes of acid phosphatase in the erythrocytes of swine, horse, dog, cat, duck and chicken

Acid phosphatase of erythrocytes of several species was investigated, with three isozymes having been recorded from swine (three types), three (two types) from horse, four (one type) from dog, two (two types) from cat, two (three types) from duck, and two (one type) from fowl. The Michaelis constant of the enzyme varied between 3.5 and 5 X 10(-4) M for the species involved. The species, however, differed slightly for the optimum pH of the enzyme. The average enzymatic activities were (5.68 +/- 0.42 for dog, 4.46 +/- 1.0 for horse, 3.8 +/- 0.24 for swine, 3.72 for cat, 2.5 +/- 0.62 for duck, and 1.9 +/- 0.8 for fowl. All values are units per gram haemoglobin. Even relatively low concentrations (0.2 or 1 mM) of copper, mercury, and cadmium ions were found to be strong inhibitors of the acid erythrocyte phosphatase.     

Biegeversuche und Prüfung des Brandverhaltens an Trägern aus verleimten Buchenschälfurnieren

Zusammenfassung An drei verleimten Tr?gern aus Buchenfurnieren wurde, das Verhalten im statischen Biegeversuch erkundet. Die Festigkeits-werte lagen zwischen den Werten, die an Tr?gern aus Buchenbrettern und aus Fichtenbrettern erzielt worden sind. Die im Brandversuch unter Last geprüften Biegetr?ger aus verleimten Buchenfurnieren, Querschnitt rd. 12 cm × 30 cm, entsprachen ungeschützt den Anforderungen der Widerstandsklasse F 30 nach DIN 4102, Blatt 2. Die Vollimpr?gnierung bewirkte einen deutlich kleineren Abbrand. Ein Tr?ger, der mit einer „Feuerschutztapete”, ummantelt war, konnte der Feuerbeanspruchung mehr als 60 min widerstehen.

---

Tests on the bending strength and fire tests with glulam-girders of beech veneers

Summary Three glulam-girders of beech veneers, were tested as to their behavior in a static bending test The strength values were found between those obtained from girders of beech boards and spruce boards. The glulam-girders of beech veneers with a cross-section of approx. 12 cm by 30 cm were subjected to a fire test under load in an unprotected condition and met, the requirements of the fire resistance class F 30 in accordance to DIN 4102, sheet 2. The full cell impregnation caused a definitely smaller fire loss. One girder, sheathed with a fire protective wall-paper, was able to resist the fire attack over more than 60 min.

---

---

Mitteilung aus dem Otto-Graf-Institut, Stuttgart

---

Die Mittel zur Durchführung der Untersuchungen sind in dankenswerter Weise vom Bayerischen Staatsministerium für Ern?hrung, Landwirtschaft und Forsten, München, über die Deutsche Gesellschaft für Holzforschung zur Verfügung gestellt worden.     

An analysis of feeding and sensorimotor abilities of rats after decortication.

Within 24 hrs after surgery, decorticate adult male Long-Evans and Sprague-Dawley rats ate mash, unfamiliar foods, dry chow, and tap and sugar water from a spatula (Exp I). They sampled nonnutritive substances but rejected noxious substances. Although initially anorectic, given mash, they arrested weight loss as early as 2–4 days. Throughout survival they had oral manipulatory difficulties with chewing food, lapping water, and trimming toenails. They showed sensorimotor neglect (Exp II) to objects touched to the body, but did orient when touched on the head. When lifted from a surface, decorticate Ss showed limb and postural abnormalities; when dropped, righting responses were impaired. Ss showed stereotyped reflexive responses to surfaces and became trapped on platforms and in alleys. The range of abnormalities, from simple acts of chewing to more complex behaviors of orienting and escaping traps, showed that Ss were impaired to such an extent that they would not survive in any but the simplest environment. (60 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Environmental constraints on motor abilities used in grooming, swimming, and eating by decorticate rats.

Successive tests reexamined the grooming, swimming, and eating behaviors of 20 decorticate male Long-Evans rats by evoking the behaviors in various circumstances (stimulus conditions). Ss showed normal-length grooming sequences during spontaneous home cage grooming; when grooming was elicited by removing them from their home cage and soaking their fur by a brief swim, grooming sequences were shorter. In cold water (18°C), Ss swam well and with exaggerated vigor and frequently inhibited forelimb movements; in warm water (37°C), they swam poorly and paddled with all 4 limbs. To eat small pieces of food, Ss sat up and used forepaws as do normal rats, but they frequently dropped the food; they did not use their forepaws to eat large pieces of food. When given powdered food, they first tried to grasp it in their mouth while they scratched at the floor surface with their front limbs; thereafter, they became increasingly proficient in licking it up. Thus, in a narrow range of stimulus conditions, decorticate rats can make movements resembling those of normal ones. They also improve with practice in some tasks but not in others. In order to elucidate the role of the cortex in control of motor behavior, it is considered necessary to obtain "behavior profiles" of each behavior by testing the animals repeatedly and under widely varying test conditions. (36 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparisons of behavioral effects of hippocampal and prefrontal cortex lesions in the rat.

5 groups of 5 male Wistar rats each, with aspiration lesions of dorsomedial frontal cortex, ventrolateral frontal cortex, hippocampus, or posterior cortex, or with sham operations, were tested in 5 behavioral situations: emotionality assessment, serial spatial reversals, 70:30 spatial probability, differential reinforcement of low rates (DRL), and barpress extinction. Ss with posterocortical lesions did not differ from operated controls on any task. The effects of lesions in the 2 anatomically defined frontal subfields were clearly dissociated on spatial reversals, spatial probability, and DRL. Lesions in either subfield produced a significant increase in emotionality relative to controls, and neither lesion affected barpress extinction. Results suggest that both frontal subfields may be functionally related to the hippocampus but in different ways. (31 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Synthesis of Microporous Carbon Nanofibers and Nanotubes from Conjugated Polymer Network and Evaluation in Electrochemical Capacitor

One‐dimensional fibers and tubes are constructed through the oriented carbon‐carbon cross‐linking reactions towards rigid conjugated polymer networks. As the result, a template‐free and one‐step synthesis of CNTs and CNFs is achieved through a simple carbonization of the as‐formed carbon‐rich tubular and fiberlike polyphenylene precursors under argon. Microporous CNTs and CNFs with a surface area up to 900 m² g^–1 are obtained, together with HR‐TEM characterizations indicating the formation of intrinsic microporous structure in these rigid carbon‐rich networks. The primary electrochemical experiments reveal their promising applications as advanced electrodes in electrochemical double‐layered capacitor (EDLC).     

Crystalline Nanorods as Possible Templates for the Synthesis of Amorphous Biosilica during Spicule Formation in Demospongiae

In tandem : High‐resolution TEM shows that during the initial stages of demosponge spicule formation, a primordial crystalline structure is formed within the axial filament. The recently developed electron diffraction tomography technique (ADT) reveals that the nanorods have a layered structure that matches smectitic phyllosilicates. These intracellular nanorods have been considered as precursors of mature spicules.