Changes of X-prolyl dipeptidyl-aminopeptidase activity in developing rat brain.

We found X-prolyl dipeptidyl-aminopeptidase activity in rat brain and examined the developmental changes at various ages. The total enzyme activity per brain increased until 4 weeks of age, and then decreased during maturation. Specific activity in young rat brain was higher than that in adult rat brain. The properties of the brain enzyme were different from those of pituitary and other tissues.     

Changes of X-prolyl dipeptidyl-aminopeptidase activity in developing rat brain

Summary We found X-prolyl dipeptidyl-aminopeptidase activity in rat brain and examined the developmental changes at various ages. The total enzyme activity per brain increased until 4 weeks of age, and then decreased during maturation. Specific activity in young rat brain was higher than that in adult rat brain. The properties of the brain enzyme were different from those of pituitary and other tissues.     

Neuroimaging, nutrition, and iron-related genes

Several dietary factors and their genetic modifiers play a role in neurological disease and affect the human brain. The structural and functional integrity of the living brain can be assessed using neuroimaging, enabling large-scale epidemiological studies to identify factors that help or harm the brain. Iron is one nutritional factor that comes entirely from our diet, and its storage and transport in the body are under strong genetic control. In this review, we discuss how neuroimaging can help to identify associations between brain integrity, genetic variations, and dietary factors such as iron. We also review iron’s essential role in cognition, and we note some challenges and confounds involved in interpreting links between diet and brain health. Finally, we outline some recent discoveries regarding the genetics of iron and its effects on the brain, suggesting the promise of neuroimaging in revealing how dietary factors affect the brain.     

Morphology of the carnation-light synthetic lethal focus in Drosophila melanogaster

A histological study of the carnation-light lethal focus revealed morphological abnormalities in brain tissue. The ratio of core width to total brain width and brain texture consistently differed between lethal (car-lt) and their non-lethal sibs.     

Morphology of the carnation-light synthetic lethal focus inDrosophila melanogaster

Summary A histological study of the carnation-light lethal focus revealed morphological abnormalities in brain tissue. The ratio of core width to total brain width and brain texture consistently differed between lethal (car-lt) and their non-lethal sibs.     

Brain factor from Galleria mellonella (Lepidoptera) stimulating silk gland activity.

Brain extracts from day 1-4 last instar larvae of Galleria mellonella (Lepidoptera) stimulate RNA synthesis in cultured silk glands from day 3 last instar larvae. When the fibroin-synthesizing posterior parts of silk glands were incubated for 3 h in vitro in the presence of brain extract (0.1 brain equivalent), [3H]-uridine incorporation into RNA was stimulated more than twofold. The stimulating effect of brain extract showed a dose response relationship. It is suggested that the heat-resistant and protease-sensitive brain factor is a peptide.     

The serum levels of unbound bilirubin that induce changes in some brain mitochondrial reactions in newborn guinea-pigs

Bilirubin in different concentrations was injected in newborn guinea-pigs and the following parameters were determined: serum total and unbound bilirubin, whole brain bilirubin content and oxygen consumption, NADH-cytochrome c reductase and ATPase activities in brain mitochondria. The results showed a significant correlation between decreased rates of brain metabolism and the elevation of serum total and unbound bilirubin.     

Aneuploidy in the normal and diseased brain

The brain is remarkable for its complex organization and functions, which have been historically assumed to arise from cells with identical genomes. However, recent studies have shown that the brain is in fact a complex genetic mosaic of aneuploid and euploid cells. The precise function of neural aneuploidy and mosaicism are currently being examined on multiple fronts that include contributions to cellular diversity, cellular signaling and diseases of the central nervous system (CNS). Constitutive aneuploidy in genetic diseases has proven roles in brain dysfunction, as observed in Down syndrome (trisomy 21) and mosaic variegated aneuploidy. The existence of aneuploid cells within normal individuals raises the possibility that these cells might have distinct functions in the normal and diseased brain, the latter contributing to sporadic CNS disorders including cancer. Here we review what is known about neural aneuploidy, and offer speculations on its role in diseases of the brain. Received 13 April 2006; received after revision 2 June 2006; accepted 13 July 2006     

A convulsant, 3-mercaptopropionic acid,decreases the level of GABA and GAD in rat pancreatic islets and brain

To investigate the properties of the gamma-aminobutyric acid (GABA) synthesizing enzyme, glutamate decarboxylase (GAD), in the brain and the pancreatic islets of the rat, GABA concentration in the brain and the pancreatic islets was measured after intraperitoneal administration of 3-mercaptopropionic acid (3-MP) at 25 mg/kg. 60 min after the administration of 3-MP, GABA concentration in the hypothalamus, the superior colliculus and the hippocampus of the brain decreased by 20–30% and in the pancreatic islets by 35%. The concentration in the pancreatic acini did not change. Western blotting showed that GAD activity in the pancreatic islets decreased after administration of 3-MP compared to the control. The activity of GAD in the pancreatic islets as well as brain can be modified by a convulsant, in this case 3-MP. These results suggest the properties of GAD may be similar in the pancreatic islets and brain.     

Monoamines in brain and urine of rats with hereditary hypothalamic diabetes insipidus

Summary Monoamine levels in brain and urine of homozygous and heterozygous diabetes insipidus (DI) rats (Brattleboro strain) were assessed. Homozygous DI rats had a higher whole brain content of serotonin than their heterozygous littermates. However, when corrected for differences in brain weight, homozygous DI also appeared to have higher brain concentrations of noradrenaline, tyrosine and GABA. The total 24 h excretion of all amines and their precursors was greater in the homozygous than in the heterozygous rats.The authors thankHerman Müller andIneke van de Veerdonk for their assistance with part of this study.     

Inter omental-cerebral vascularization induced by omental graft to the rat brain

Summary The omentum of 13 rats were removed from the abdomen and placed directly on the brain. 5–14 days later the omentum and the underlying brain were joined by numerous vascular anastomoses in 9 rats. The purpose of this work was to study the use of omentum to establish extracranial vascularization of the brain.Supported by funds from Grant RR 514 from the Jefferson Medical College General Research Fund.     

Glutamine synthetase activity during mouse brain development

The specific activity of glutamine synthetase (GS) in mouse brain was 2-fold higher in the olfactory bulbs than in other regions. After birth, the specific activity of GS increased more rapidly in medulla oblongata and in olfactory bulbs, than in cerebral and cerebellar cortex. The activity of GS in primary cultures of brain hemispheres increased more slowly than in homogenates of whole brains. However, when astroblasts were treated in vitro with glucocorticoids or mouse brain extracts, GS activity reached 4 times the level measured in the homogenate of an adult mouse brain. We conclude that levels of GS activity may relate to the maturation of astrocytes, and propose that GS may be used as a marker of astrocytic maturation.     

Glutamine synthetase activity during mouse brain development

Summary The specific activity of glutamine synthetase (GS) in mouse brain was 2-fold higher in the olfactory bulbs than in other regions. After birth, the specific activity of GS increased more rapidly in medulla oblongata and in olfactory bulbs, than in cerebral and cerebellar cortex. The activity of GS in primary cultures of brain hemispheres increased more slowly than in homogenates of whole brains. However, when astroblasts were treated in vitro with glucocorticoids or mouse brain extracts, GS activity reached 4 times the level measured in the homogenate of an adult mouse brain. We conclude that levels of GS activity may relate to the maturation of astrocytes, and propose that GS may be used as a marker of astrocytic maturation.     

Brain response to calorie restriction

Calorie restriction extends longevity and delays ageing in model organisms and mammals, opposing the onset and progression of an array of age-related diseases. These beneficial effects also extend to the maintenance of brain cognitive functions at later age and to the prevention, at least in rodents, of brain senescence and associated neurodegenerative disorders. In recent years, the molecular mechanisms underlying brain response to calorie restriction have begun to be elucidated, revealing the unanticipated role of a number of key nutrient sensors and nutrient-triggered signaling cascades in the translation of metabolic cues into cellular and molecular events that ultimately lead to increased cell resistance to stress, enhanced synaptic plasticity, and improved cognitive performance. Of note, the brain’s role in CR also includes the activation of nutrient-sensitive hypothalamic circuitries and the implementation of neuroendocrine responses that impact the entire organism. The present review addresses emerging molecular themes in brain response to dietary restriction, and the implications of this knowledge for the understanding and the prevention of brain disorders associated with ageing and metabolic disease.     

Distribution of glycerophosphorylcholine diesterase in rat brain.

The distribution of glycerylphosphorylcholine diesterase in the rat brain has been examined. The enzyme was evenly distributed throughout the brain but was localized in the synaptosome (nerve ending) fraction which was prepared by ultracentrifugation.     

Distribution of glycerophosphorylcholine diesterase in rat brain

Summary The distribution of glycerylphosphorylcholine diesterase in the rat brain has been examined. The enzyme was evenly distributed throughout the brain but was localized in the synaptosome (nerve ending) fraction which was prepared by ultracentrifugation.     

盐酸戊乙奎醚对大鼠感染性脑水肿AQP4表达的影响

目的：研究盐酸戊乙奎醚对感染性脑水肿保护作用的机制。方法：采用左颈内动脉注射脂多糖复制大鼠感染性脑水肿模型,将84只雄性SD大鼠随机分为对照组（C组）、水肿组（I组）、盐酸戊乙奎醚治疗组（P组）。检测6h、12h、24h、48h时各组大鼠脑组织含水量、病理形态;脑组织SOD活性、MDA含量;免疫组化法及RT—PCR法检测AQP4蛋白分布与AQP4mRNA含量。结果：（1）与C组相比,I组、P组脑含水量、MDA含量均升高,同时SOD活性、AQP4蛋白、AQP4mRNA表达均减少（P〈0．01）。与对应时间点P组相比,I组脑含水量、MDA含量均升高,同时SOD活性、AQP4蛋白、AQP4mRNA表达均减少,于24h达高峰,48h仍在较高水平（P〈0．01）。（2）脑组织光镜检查：I组大鼠脑组织损伤严重,P组损伤明显减轻。结论：盐酸戊乙奎醚能在一定程度上可减轻感染所致的脑组织损伤,上调AQP4表达,对脑水肿有一定治疗作用,其机制可能与抗氧化作用有关。     

Pre- and postnatal lead exposure affects the serotonergic system in the immature rat brain

Summary The effect of pre- and postnatal lead exposure on the development of the serotonergic system in striatum and brain stem was investigated. Serotonin and its metabolite 5-HIAA where determined by HPLC-EC. A significant decrease of 5-HT was detected in the brain stem at postnatal day 28. At both days 6 and 28 postnatal, 5-HIAA was reduced in striatum and brain stem. The results provide support to the hypothesis that developing 5-HT neurons are sensitive to relatively low levels of lead exposure.     

Pre- and postnatal lead exposure affects the serotonergic system in the immature rat brain.

The effect of pre- and postnatal lead exposure on the development of the serotonergic system in striatum and brain stem was investigated. Serotonin and its metabolite 5-HIAA where determined by HPLC-EC. A significant decrease of 5-HT was detected in the brain stem at postnatal day 28. At both days 6 and 28 postnatal, 5-HIAA was reduced in striatum and brain stem. The results provide support to the hypothesis that developing 5-HT neurons are sensitive to relatively low levels of lead exposure.     

Brain factor fromGalleria mellonella (Lepidoptera) stimulating silk gland activity

Brain extracts from day 1–4 last instar larvae ofGalleria mellonella (Lepidoptera) stimulate RNA synthesis in cultured silk glands from day 3 last instar larvae. When the fibroin-synthesizing posterior parts of silk glands were incubated for 3 h in vitro in the presence of brain extract (0.1 brain equivalent), [³H]-uridine incorporation into RNA was stimulated more than twofold. The stimulating effect of brain extract showed a dose response relationship. It is suggested that the heat-resistant and protease-sensitive brain factor is a peptide.