Lesions of the basal forebrain cholinergic system in mice disrupt idiothetic navigation

Loss of integrity of the basal forebrain cholinergic neurons is a consistent feature of Alzheimer's disease, and measurement of basal forebrain degeneration by magnetic resonance imaging is emerging as a sensitive diagnostic marker for prodromal disease. It is also known that Alzheimer's disease patients perform poorly on both real space and computerized cued (allothetic) or uncued (idiothetic) recall navigation tasks. Although the hippocampus is required for allothetic navigation, lesions of this region only mildly affect idiothetic navigation. Here we tested the hypothesis that the cholinergic medial septo-hippocampal circuit is important for idiothetic navigation. Basal forebrain cholinergic neurons were selectively lesioned in mice using the toxin saporin conjugated to a basal forebrain cholinergic neuronal marker, the p75 neurotrophin receptor. Control animals were able to learn and remember spatial information when tested on a modified version of the passive place avoidance test where all extramaze cues were removed, and animals had to rely on idiothetic signals. However, the exploratory behaviour of mice with cholinergic basal forebrain lesions was highly disorganized during this test. By contrast, the lesioned animals performed no differently from controls in tasks involving contextual fear conditioning and spatial working memory (Y maze), and displayed no deficits in potentially confounding behaviours such as motor performance, anxiety, or disturbed sleep/wake cycles. These data suggest that the basal forebrain cholinergic system plays a specific role in idiothetic navigation, a modality that is impaired early in Alzheimer's disease

The role of p75NTR in cholinergic basal forebrain structure and function

The role of the p75 neurotrophin receptor (p75NTR) in adult cholinergic basal forebrain (cBF) neurons is unclear due to conflicting results from previous studies and to limitations of existing p75NTR-knock-out mouse models. In the present study we used a novel conditional knock-out line (ChAT-cre p75in/in) to assess the role of p75NTR in the cBF by eliminating p75NTR in choline acetyl-transferase-expressing cells. We show that the absence of p75NTR results in a lasting increase in cBF cell number, cell size, and cholinergic innervation to the cortex. Analysis of adult ChAT-cre p75in/in mice revealed that mutant animals show a similar loss of cBF neurons with age to that observed in wild-type animals, indicating that p75NTR does not play a significant role in mediating this age-related decline in cBF neuronal number. However, the increased cholinergic axonal innervation of the cortex, but not the hippocampus, corresponded to alterations in idiothetic but not allothetic navigation. These findings support a role for p75NTR-mediated regulation of cholinergic-dependent cognitive function, and suggest that the variability in previous reports of cBF neuron number may stem from limited spatial and temporal control of p75NTR expression in existing knock-out models

Prinos i kvalitet krtola krompira u zavisnosti od đubrenja

Research on the effect of different rates and methods of application of mineral NPK fertilizers on the yield and quality of potato variety ‘Carrera’ was conducted on a luvisol of the Radočelo Mountain massif. Treatments included an unfertilized control, NPK 16:16:16 (1500 kg ha) applied in-furrow at planting, NPK 16:16:16 (1200kg ha-1) applied in-furrow at planting, and NPK 16:16:16 applied at 700 kg ha-1 during seedbed preparation and 500 kg ha-1 in-furrow at planting. Mineral fertilizers led to a very significant increase in tuber yield compared to the control, giving the highest total yield under 1500 kg ha-1 NPK treatment. Results on the nutritional value of potato tubers showed that the levels of tested nutrients were higher in the skin than in the flesh. The concentrations of tested nutrients in potato tubers were highest at the highest NPK fertilizer rate.Ispitivanje uticaja različitih doza i načina primene mineralnog đubriva NPK 16:16:16 (1500 kg ha-1, primenjenog u brazde zavreme sadnje, 1200 kg ha-1, primenjenog u brazde za vreme sadnje i 700 kg ha-1 za vreme predsetvene pripreme uz 500 kg ha-1 u brazde za vreme sadnje) na prinos i kvalitet krompira sorte Karera izvedeno je na lesiviranom zemljištu (luvisolu) planinskog masiva Radočelo. Primenjena mineralna đubriva su uticala na značajno povećanje prinosa u odnosu na kontrolu, pri čemu je značajno veći prinos postignut na varijanti sa većom količinom đubriva u odnosu na ostale varijante. Primena iste doze NPK đubriva različitim načinima unošenja nije značajno uticala na prinos i kvalitet krtola krompira. Analizom krtola krompira je utvrđeno da je sadržaj svih elemenata bio veći u kori u odnosu na srž krtole, kao i da je najveći sadržaj bio na varijanti sa najvećom dozom NPK đubriva

Stanje ribarstva u Srbiji

Fishery in Serbia comprises of aquaculture and fishery. Aquaculture in Serbia concerns fish culturing. For production of other aquatic animals, mainly ornamental plants and crayfish, only occasional interest and small scale production in aquarium type of units exists. Fish are produced in carp and trout fish farms (over 95%), to a smaller extent in cages, enclosed or partitioned natural or man made aquatic ecosystems. Aquaria fish culture is mainly low scale, with a small number of specialized breeders and one public aquarium (M a r k o v i ć i M i t r o v i ć T u t u n d ž i ć, 2003, 2005; M a r k o v i ć i P o l e k s i ć, 2007, M a r k o v i ć i sar., 2009). In Serbia freshwater species cultured are: common carp, white and gray bighead, wells, pike perch, rainbow trout and to a lesser degree Northern pike, tench, brown trout, beluga, Russian starlet. There is 13 500 – 14 000 ha of fish farms in Serbia, with 99.9% of carp farms and 0.1% of trout farms. The total fish production in recent years is between 10 000 and 15 000 tons with 70 to 75% of consumable fish. All three types of production systems are present: extensive, semi-intensive and intensive. Extensive production is sporadic and is present only at a few carp production units, mostly not economic for semi-intensive production due to remoteness from other production units or neglect. The principal type of production (75 – 80%) is semi-intensive production of cyprinids, with common carp as the main species. Common carp is present with more than 80% of the total production in warmwater fish farms. The traditional (old) type of feeding is slowly changing. Cereals are more often, at over 50% of production surfaces, totally of partially replaced by complete, peletted and even more extruded feed. This has resulted in an increase of production per surface unit in recent years. Intensive production systems in carp culture are less present, at a small number of earthen ponds with aeration systems, mainly for fish fry production, and in cages. However, rainbow trout, the only salmonid species cultured for consummation, is exclusively produced in intensive systems at trout farms in Serbia. The number of people involved full-time in fish production in Serbia is about 1100 and approximately 400 seasonal workers that are hired mainly prior to harvest. With the rising of standard and returning to traditional habits during religious fasting, as well as with a slow increase of “healthy food” supporters, fish consumption has a growing trend. However, although fish production is increasing in recent years, the country’s production and open-water capture fishery barely represent a quarter of the total needs of inhabitants. This results in increase of import, mainly marine and frizzed fish, but also freshwater fish. Open-water capture fishery is performed in Serbia’s fishing waters. They are represented by 66 000 km of water currents (rivers and streams), flood plains, backwaters, 50 lakes, 150 reservoir lakes and around 30 000 km of canal systems, hydromeliorative systems, as well as all other waters with fish. All fishing waters are divided into 6 fishing regions (Serbia – Vojvodina, Serbia – West, Serbia – South West, Srbia - South, Serbia – East, Serbia – Center) since year 2007. Sports fishing is obtainable at all regions but commercial fishery is aloud only at two regions (Serbia – Vojvodina, Serbia – west), and in rivers Tisa, Sava and Danube. Number of fisherman with purchased license in the last couple of years is between 50 000 and 100 000. Number of commercial fishermen is between 500 and 2000 in the last ten years. The amount of captured fish is between 2000 and 3000 tons in the few past years

Electrical properties and percolation concentration in Si3N4-TiN based composites

Electrical resistivity Of Si3N4-TiN based composites obtained during liquid phase sintering was investigated regarding the amount of TiN and influence of yttria and various rare earth oxides used as sintering aids. The electrical resistivity of composites decreases remarkably at certain concentration of conductive TiN phase, known as percolation concentration. In this paper different conductivity models have been reviewed in order to discuss the experimental results. On the basis of starting particle size and microstructure characteristics the computer simulation of conductivity-concentration curves have been done and corresponding parameters that determine the power of conductivity were determined.7th Conference of the European-Ceramic-Society, Sep 09-13, 2001, Brugge, Belgiu

Acute Down-regulation of BDNF Signaling Does Not Replicate Exacerbated Amyloid-beta Levels and Cognitive Impairment Induced by Cholinergic Basal Forebrain Lesion

Degeneration of basal forebrain cholinergic neurons (BFCNs) precedes hippocampal degeneration and pathological amyloid-beta (A beta) accumulation, and underpins the development of cognitive dysfunction in sporadic Alzheimer's disease(AD). We hypothesized that degeneration of BFCNs causes a decrease in neurotrophin levels in innervated brain areas, which in turn promotes the development of A beta pathology and cognitive impairment. Here we show that lesion of septo-hippocampal BFCNs in a pre-symptomatic transgenic amyloid AD mouse model (APP/PS1 mice) increases soluble A beta levels in the hippocampus, and induces cognitive deficits in a spatial memory task that are not seen in either unlesioned APP/PS1 or non-transgenic littermate control mice. Furthermore, the BFCN lesion results in decreased levels of brain-derived neurotrophic factor (BDNF). However, viral knockdown of neuronal BDNF in the hippocampus of APP/PS1 mice (in the absence of BFCN loss) neither increased the level of A beta nor caused cognitive deficits. These results suggest that the cognitive decline and A beta pathology induced by BFCN loss occur independent of dysfunctional neuronal BDNF signaling, and may therefore be directly underpinned by reduced cholinergic neurotransmission

Role of bioinformatics as a tool for oilseed Brassica species

Genetics and genomics have progressed rapidly in the last decade due in part to the increased automation in the generation of data. Biology is now very much an information science and bioinformatics provides the means to connect biological data to hypotheses. Bioinformatics applications assist with the processing and management of this genetic, genomic and phenotypic data as well as providing interfaces for the interrogation and use of this data for conventional biologists. In this chapter, we describe tools fo rthe rapid and automated discovery of SNP and SSR molecular markers, the management and visualisation of genetic mapping data, the interrogation second generation DNA sequence data and the annotation and visualisation of assembled genome information

Acute Down-regulation of BDNF Signaling Does Not Replicate Exacerbated Amyloid-β Levels and Cognitive Impairment Induced by Cholinergic Basal Forebrain Lesion

Degeneration of basal forebrain cholinergic neurons (BFCNs) precedes hippocampal degeneration and pathological amyloid-beta (Aβ) accumulation, and underpins the development of cognitive dysfunction in sporadic Alzheimer’s disease (AD). We hypothesized that degeneration of BFCNs causes a decrease in neurotrophin levels in innervated brain areas, which in turn promotes the development of Aβ pathology and cognitive impairment. Here we show that lesion of septo-hippocampal BFCNs in a pre-symptomatic transgenic amyloid AD mouse model (APP/PS1 mice) increases soluble Aβ levels in the hippocampus, and induces cognitive deficits in a spatial memory task that are not seen in either unlesioned APP/PS1 or non-transgenic littermate control mice. Furthermore, the BFCN lesion results in decreased levels of brain-derived neurotrophic factor (BDNF). However, viral knockdown of neuronal BDNF in the hippocampus of APP/PS1 mice (in the absence of BFCN loss) neither increased the level of Aβ nor caused cognitive deficits. These results suggest that the cognitive decline and Aβ pathology induced by BFCN loss occur independent of dysfunctional neuronal BDNF signaling, and may therefore be directly underpinned by reduced cholinergic neurotransmission