IMMUNOHISTOCHEMICAL IDENTIFICATION AND DISTRIBUTION OF GLUTAMATERGIC NMDA AND mGlu1 RECEPTORS IN THE PONTINE INTERTRIGEMINAL REGION IN RATS

Local glutamate simulation of intertrigeminal region (ITR) in the lateral pons evoked immediate cardiovascular and respiratory effects proposing its role in central cardiorespiratory control. Since pharmacological studies provided only functional evidence for the existence of glutamate receptors in the ITR and thereby specifying putative neurochemical substrate involved in this control, here we employed immunohistochemistry to examine expression and distribution of NMDA and mGlu1 receptors in this structure. Thirty adult male Sprague-Dawley rats were perfuse-fixed, their brains frozen and cut into sequential series of 20 µm thick sections through the ITR. Immunohistochemistry was performed using polyclonal antibodies against NMDA-NR1, NMDA-NR2A and mGlu1 receptors. Labeled neurons in the ITR were analyzed using light microscope and computerized image analysis system for quantification of relative immunoreactivity as the mean of integrated optical density (IOD), and counting the immunopositive cells. Light microscopic analyses demonstrated NMDA-NR1-immunoreactivity mainly localized in the neuronal cell bodies with sparse distribution on primary dendrites, while NMDA-NR2A-immunoreactivity was basically somatically distributed. The mGlu1-immunoreactivity was moderate and observed both in neuronal bodies and primary dendrites or extracellular matrix suggesting somatodendritic localization. Quantitative analyses of IOD showed very strong expression of NMDA-NR1, weak of NMDA-NR2A and strong-to-moderate expression of mGluR1, with differences in immunostaining signal distribution over rostro-caudal span of the ITR. Counting of immunopositive cells followed similar expression profile. Our data directly confirm the presence of glutamatergic NMDA and mGlu1 receptors in the ITR apparently involved in signaling pathways by which this region modulates cardiorespiratory functions such as blood pressure, heart rate and breathing

Salicylic Acid Attenuates Gentamicin-Induced Nephrotoxicity in Rats

Gentamicin (GM) is a widely used antibiotic against serious and life-threatening infections, but its usefulness is limited by the development of nephrotoxicity. The present study was designed to determine the protective effect of salicylic acid (SA) in gentamicin-induced nephrotoxicity in rats. Quantitative evaluation of gentamicin-induced structural alterations and degree of functional alterations in the kidneys were performed by histopathological and biochemical analyses in order to determine potential beneficial effects of SA coadministration with gentamicin. Gentamicin was observed to cause a severe nephrotoxicity which was evidenced by an elevation of serum urea and creatinine levels. The significant increases in malondialdehyde (MDA) levels and protein carbonyl groups indicated that GM-induced tissue injury was mediated through oxidative reactions. On the other hand, simultaneous SA administration protected kidney tissue against the oxidative damage and the nephrotoxic effect caused by GM treatment. Exposure to GM caused necrosis of tubular epithelial cells. Necrosis of tubules was found to be prevented by SA pretreatment. The results from our study indicate that SA supplement attenuates oxidative-stress associated renal injury by reducing oxygen free radicals and lipid peroxidation in gentamicin-treated rats

Nutrients status in maize grain from sustainable agriculture

Maize cultivation with application of proper organic and bio-fertilizers could increase nutritional value of crop grain and maintain soil fertility. The aim of the study was to examine variations in concentrations of phytate, soluble phenols, total glutathione (GSH), yellow pigment (YP), DPPH radical scavenging capacity (DPPH), Ca, Mg, Fe, Zn and Mn in maize hybrids with white, yellow and red colour grain, under the influence of bio-, organic fertilizer and urea in regard to control (without fertilization). Results indicated that phytate, DPPH, Ca, Mg and, Mn varied slightly (< 10%). Red grain maize was characterized with the highest concentrations of phenols, Ca, Mg, Fe, Zn, and DPPH. White grain maize, particularly in urea and bio-fertilizer treatment, accumulated higher GSH values, while red and especially yellow grain hybrid accumulated higher YP amount in urea treatment. Irrespective to lower variations in Mn concentration, higher values were determined in yellow hybrid. Organic fertilizer mainly induced increase in Mg bio-fertilizer which positively affected Fe accumulation, while urea caused higher Zn and Mn accumulation in maize grain. It could be concluded that yellow and particularly red grain hybrid enabled increased accumulation of mineral elements, together with higher DPPH values, mainly in treatments with organic fertilizer and urea giving it advantage in production of highly nutritious food

The role of sustainable agriculture in production of nutrient dense food

Industrialization of agriculture, as the main food source, resolved the problem of food quantity, but other problems, present in environment degradation and hidden malnutrition (deficiency in essential minerals and vitamins) were upraised. The situation is aggravating when climate change was taken into account, whereas conventional agriculture is highly contributing to climate change. Thus, a shift to sustainability paradigm and systems are a necessary solution. Sustainable systems combine various measures to achieve a high and nutrient dense yield of agricultural crops and to preserve or improve agro ecosystem. Soil recovery could be realized by increasing soil organic matter, diversity of soil microbiota and other organisms, as a part of the agro ecosystem balance, thus contributing to the increased productivity and food quality. Together, sustainable agriculture and sustainable food systems, have an important role in the health enhancement of humankind and the agro ecosystem

Adaptation of food production systems to global changes

Agricultural plants, mainly for food production are prone to variability of agro-ecolog ical conditions, particularly to meteorological conditions.Relatively frequent meteo rological extremes are reflecting negatively on agro-ecosystem, depleting soil fertility and raising its erosion, spreading invasive weeds, hard to control, thus reducing rapidly arable areas. At the same time, meteorological extremes are diminishing production of agricultural plants, their yields, as well as quality, reflecting negative on food security. It is well known that reduced yields of staple crops, like wheat, maize, rice and others are present in drier seasons, while increased concentration of protein, some vitamins and antioxidants is pres ent at the same time. However, in the most of the cases higher infestation with pathogenic fungus is present, thus increasing mycotoxines level. Meteorological extremes are mainly driven by anthropogenic factors, which are also responsible for reduced quality of agri cultural products. For example, globalisation trends mirrored through “Green revolution” were conceptualised to resolve worldwide hunger, by introducing of high yield genotypes, prone to stressful conditions, together with high inputs of water, mineral fertilizers (mainly based on nitrogen, phosphorus and potassium) and other toxic agro-chemicals, impairing agro-ecosystem by reduction of biodiversity, depleting of soil fertility through decrease of organic matter, microbiome diversity and particularly micro-elements, important for both, plants and humans, thus contributing to the low quality of produced food, i.e. hidden mal nutrition. Worldwide present malnutrition with essential minerals and vitamins contrib utes to the rapid increase of chronic diseases, such as inflammation, metabolic syndrome, diabetes, cardio-vascular diseases, cancer, variety of auto-immune conditions, etc. even to the pandemic level.One of the important facts lies in depletion of phosphorus deposits, leaving agriculture without the main source of this essential mineral. Novel trends that in troduce recycling, usage of alternative, renewable and less used sources of plant nutrients and energy, from the point of rationalisation, together with breeding of genotypes tolerant to various abiotic and biotic stressors, such as meteorological extremes, plant pathogens and low inputs could contribute not just to increased security of plant production, but also to increased quality of agricultural product

Sustainable fertilization systems as a prerequisite for improved quality of agricultural products

Human health is dependent not just on diet, but mainly on quality of agricultural products as a part of diet. If crops were grown on poorly fertile soils, or they are exposed to severe stresses, lesser amount of mineral elements, particularly essential elements, such as zinc, copper, manganese, magnesium, calcium, iron, and even sulphur, will be absorbed and accumulated, resulting in their deficiency in diets and increased incidence of various chronic diseases. Together with naturally low soil fertility, climate change, intensive agriculture is one of the main contributors of soil depletion. Thus, various long-term strategies, which are sustainable for agricultural plants and soils, at the same time, must be developed. It is of particular importance to increase a level of organic matter, as a source of mineral nutrients from the soil. The application through soil, as well as via plant foliage of various complex and organic fertilizers, containing macro- and micro-elements, and many stimulating compounds, enables better absorption and metabolisation of nutrients required for plants and nutrients essential for humans. Besides, bio-fertilizers, containing beneficial microorganisms have an important role in nutrients mobilization in soils, particularly from poorly accessible forms. Many bio fertilizers contain microorganisms that are able to absorb atmospheric nitrogen, thus enriching soil, delivering it to the plants, enabling reduction in amount and costs of nitrogen addition into the soil. Promoting microorganisms are also able to enhance plants ability to absorb water and nutrients by their synergy with roots, resulting in stable and better growth performances of agricultural plants, thus increasing yield and its quality. Some other cropping practices, such as crop rotation, intercropping and use of cover crops, enriches soil with organic matter, reduces losses of nutrients through recycling of harvest residues, therefore increasing soil fertility, as well as quantity and quality of crop yield, at the same time

Combined effect of cover crops and bio-fertilizer on sustainable popcorn maize production

Cover crops play an important role in low-input cropping systems, increasing the use of agro-ecosystem services. Due to the lack of information about the impact of cover crops and bio-fertilizers on popcorn maize (Zea mays everta Sturt.) growth and yield quality, especially the popping volume and nutritive quality, such as concentrations of protein and mineral elements, this research aimed to provide essential information. The interrelation between popcorn maize productivity and quality with important groups of soil microorganisms presents additional novelty. The results demonstrated that field pea is a beneficial cover crop, especially when combined with a bio-fertilizer, supporting the accumulation of maize biomass, chlorophyll, yield potential, and the concentrations of protein, Ca, Mg, Fe, and Zn. In addition, field pea residues promoted N-fixing bacteria, and the number of total microorganisms, especially actinomycetes and decomposing bacteria, which could promote nutrient uptake and grain quality. Residues of cover crop mixtures, common vetch + winter oats and field pea + winter oats, promoted the total number of microorganisms in the soil, and up to the end of vegetation, a greater number of decomposition and ammonification microorganisms were found, especially when the bio-fertilizer was applied, which consequently could support greater maize biomass. Popping volume, as a main trait of popcorn maize, had the highest value in the common vetch + winter oats variant, supporting again the statement that quality traits could be enhanced in sustainable production. Unlike living cover crops, mulch mainly affected soil microbial communities and promoted the development of actinomycetes and cellulolytic microorganisms during the growing season. The results of this research could contribute to the development of sustainable popcorn maize production for improved grain quality. They could also serve as a basis for isolating beneficial soil microorganisms to develop new bio-fertilizers that could improve maize production in synergy with cover crop

Cerebellar Kv3.3 potassium channels activate TANK-binding kinase 1 to regulate trafficking of the cell survival protein Hax-1.

Mutations in KCNC3, which encodes the Kv3.3 potassium channel, cause degeneration of the cerebellum, but exactly how the activity of an ion channel is linked to the survival of cerebellar neurons is not understood. Here, we report that Kv3.3 channels bind and stimulate Tank Binding Kinase 1 (TBK1), an enzyme that controls trafficking of membrane proteins into multivesicular bodies, and that this stimulation is greatly increased by a disease-causing Kv3.3 mutation. TBK1 activity is required for the binding of Kv3.3 to its auxiliary subunit Hax-1, which prevents channel inactivation with depolarization. Hax-1 is also an anti-apoptotic protein required for survival of cerebellar neurons. Overactivation of TBK1 by the mutant channel leads to the loss of Hax-1 by its accumulation in multivesicular bodies and lysosomes, and also stimulates exosome release from neurons. This process is coupled to activation of caspases and increased cell death. Our studies indicate that Kv3.3 channels are directly coupled to TBK1-dependent biochemical pathways that determine the trafficking of cellular constituents and neuronal survival

TOPOGRAPHIC IDENTIFICATION OF THE PONTOMEDULLARY RESPIRATORI-SENSITIVE NUCLEI OF THE RAT BRAIN BY GLUTAMATE MICRO-STIMULATIONS

Automatic control of breathing is highly dependent on the integrity of the pontomedullary network of reciprocally connected neurons localized in a number of functionally and neurochemically different compartments. Glutamate is considered the key neurotransmitter mediating signal transmission in the respiratory regions of the brainstem. Identification of the respiratory-sensitive neurons using this neurotransmitter for microstimulations provides an insight into the topographic organization of the pontomedullary nuclei involved in the modulation and control of breathing.Three types of respiratory responses were observed following glutamate microinjections: hyperpnea, apneusis (inspiratory cramp) and hypopnea or apnea. Hyperpnea was obtained as a result of microstimulations in the region of lateral parabrachium and caudal Kölliker-Fuse nuclei. Apneustic response was observed in the region localized ventrally from superior cerebellar peduncle, while hypopneic or apneic responses followed glutamate microinjections in the region of ventral Kölliker-Fuse nucleus and a narrow area between motor and principal sensory trigeminal nucleus, which is referred to as intertrigeminal region.Anatomical distribution of the obtained respiratory responses depends on the localization of microinjections and ascendant and descendent projections stemming from the sites of stimulation

Neurophysiological signals as predictive translational biomarkers for Alzheimer’s disease treatment: effects of donepezil on neuronal network oscillations in TgF344-AD rats

Abstract Background Translational research in Alzheimer’s disease (AD) pathology provides evidence that accumulation of amyloid-β and hyperphosphorylated tau, neuropathological hallmarks of AD, is associated with complex disturbances in synaptic and neuronal function leading to oscillatory abnormalities in the neuronal networks that support memory and cognition. Accordingly, our recent study on transgenic TgF344-AD rats modeling AD showed an age-dependent reduction of stimulation-induced oscillations in the hippocampus, and disrupted long-range connectivity together with enhanced neuronal excitability in the cortex, reflected in greatly increased expression of high-voltage spindles, an epileptic absence seizure-like activity. To better understand the translational value of observed oscillatory abnormalities in these rats, we examine here the effects of donepezil, an acetylcholine esterase inhibitor clinically approved for AD treatment. Methods Brainstem nucleus pontis oralis stimulation-induced hippocampal oscillations were recorded under urethane anesthesia in adult (6-month-old) and aged (12-month-old) TgF344-AD and wild-type rats. Spontaneous cortical activity was monitored in a cohort of freely behaving aged rats implanted with frontal and occipital cortical electroencephalography (EEG) electrodes. Results Subcutaneous administration of donepezil significantly augmented stimulation-induced hippocampal theta oscillation in aged wild-type rats and both adult and aged TgF344-AD rats, which have been previously shown to have diminished response to nucleus pontis oralis stimulation. Moreover, in adult TgF344-AD rats, donepezil also significantly increased theta phase-gamma amplitude coupling in the hippocampus during stimulation. However, neither of these effects were significantly changed in adult wild-type rats. Under freely behaving conditions, donepezil treatment had the opposite effect on cortical oscillatory connectivity in TgF344-AD and wild-type rats, and it reduced the occurrence of high-voltage spindle activity in TgF344-AD rats. Conclusions Together, these results imply that pharmacologically enhancing cholinergic tone with donepezil could partially reverse oscillatory abnormalities in TgF344-AD rats, which is in line with its clinical effectiveness in AD patients. Therefore, our study suggests good translational opportunities for these neurophysiological signals recorded in TgF344-AD rats, and their application could be considered in drug discovery efforts for developing therapies with disease-modifying potential