3D microscopy and image analysis provide reliable measurements of length, branching, density, tortuosity and orientation of tubular structures in biological samples. We present a survey of methods for analysis of large samples by measurement of local differences in geometrical characteristics. The methods are demonstrated on the structure of the capillary bed in a rat brain., J. Janáček ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Our previous experiments revealed that water intoxication and osmotic BBB disruption in the rat allow penetration of high- molecular substances into the brain and that resulting changes in the internal environment of th e CNS lead to pathological development, such as the loss of integrity of myelin. The aim of the present study was to determine whether the previously described phenomena are associated with increased water content in the brain. To answer the question following methods were used: a) water intoxication : intraperitoneal administration of distilled water, b) osmotic BBB disruption: application of mannitol (20 %) selectively into the internal carotid artery, c) brain wet weight was measured after decapitation, and subsequently (after six days in thermostat set at 86 °C) the dry weight were estimated d) in animals with 20 % and 30 % hyperhydration the degree of myelin deterioration was estimated e) animal locomotor activity was tested by continuous behavior tracking and analysis. Brai n water content after water intoxication and following the administration of mannitol was higher than in the control group. Different degrees of hyperhydration led to different levels of brain water content and to different degrees of myelin impairment. Hyperhydration corresponding to 20 % of the body weight brought about lower locomotor activity. Increased water content in the brain after the BBB osmotic disruption is surprising because this method is frequently used in the clinical practice., P. Kozler, V. Riljak, J. Pokorný., and Obsahuje bibliografii a bibliografické odkazy
Brain Awareness Week is a series of events held around the world to increase public awareness of the brain. Top Czech scientists attracted more then 1,300 students with lectures as part of the annual Brain Awareness Week that took place in the administration building of the Czech Academy of Sciences extending from 10-13 March 2008. and Gabriela Adámková.
The endothelium of different organs displays a remarkable heterogeneity, although it presents many common functional and morphological features. However, despite our knowledge of heterogeneity among endothelial cells from different sites, the differences between brain microvascular endothelial cells (BMEC) and coronary microvascular endothelial cells (CMEC) are poorly defined. The aim of this study was to investigate whether BMEC are distinct from CMEC at the protein level. Using the proteomic approach, we comparatively analyzed the proteome of cultured BMEC and CMEC. We reproducibly separated over 2000 polypeptides by using two-dimensional electrophoresis (2-DE) at pH range of 3-10. Using PDQuest software to process the 2-DE gel images, forty-seven protein spots were differentially expressed in the two-endothelial cells. Of these, thirty-five proteins are highly expressed in BMEC, whereas twelve proteins are highly expressed in CMEC. Fifteen proteins in BMEC and seven proteins in CMEC were identified with high confidence by matrix-associated laser desorption ionization time-of-flight mass spectrometer (MALDI-TOF-MS). Our data suggested that BMEC and CMEC were different in several aspects including cytokine and growth-related molecules, stress-related proteins, metabolic enzymes, signal transduction proteins and others. The identification of a set of proteins preferentially expressed in BMEC and CMEC provided new data on the heterogeneity of the endothelium., L. Lu, P.-Y. Yang, Y.-Ch. Rui, H. Kang, J. Zhang, J.-P. Zhang, W.-H. Feng., and Obsahuje bibliografii a bibliografické odkazy
The role of brain derived nitric oxide in the physiology and behavior remains disputable. One of the reasons of the controversies might be systemic side effects of nitric oxide synthase inhibitors. Therefore, under nNOS inhibition by 7- nitroindazole (7-NI) we carried out recordings of blood gasses, blood pressure and spontaneous EEG in conscious adult rats. Locomotion and spontaneous behavior were assessed in an open field. In addition skilled walking and limb coordination were evaluated using a ladder rung walking test. The blood gas analysis revealed a significant increase in pCO2 180 min and 240 min after the application of 7-NI. The power and entropy decreased simultaneously with a shift of the mean frequency of the spontaneous EEG toward slow oscillations after 7-NI treatment. The thresholds of evoked potentials underwent a significant drop and a trend towards a slight increase in the I-O curve slope was observed. 7-NI significantly suppressed open field behavior expressed as distance moved, exploratory rearing and grooming. As for the ladder rung walking test the 7-NI treated animals had more errors in foot placement indicating impairment in limb coordination. Therefore our findings suggest that 7-NI increased cortical excitability and altered some physiological and behavioral parameters., C. Boržíčková, A. Mikulecká, J. Otáhal., and Obsahuje bibliografii
The role of neuronal nitric oxide synthase (nNOS) in the pathophysiology of epilepsy and seizures remains disputable. One of the reasons why results from the acute in vivo studies display controversies might be the effect on the regulation of cerebral blood flow (CBF) during pharmacologically induced alterations of NO system. We examined neurovascular coupling in the rat sensorimotor cortex in response to transcallosal stimulation under nNOS inhibition by 7-nitroindazole (7-NI). Adult Wistar rats were anesthetized with urethane and epidural silver EEG electrodes were implanted over sensorimotor cortices. Regional CBF was measured by Laser Doppler Flowmetry (LDF). We catheterized a common carotid artery to measure arterial blood pressure (BP). 7-NI did not significantly affect blood pressure and heart rate. Electrophysiological recordings of evoked potentials (EPs) revealed no effect on their ampl itude, rhythmic potentiation or depression of EPs. Transcallosal stimulation of the contralateral cortex induced a frequency dependent rise in CBF. Although 7-NI did not significantly affect basal CBF and cortical excitability, hemodynamic responses to the transcallosal stimulation were diminished implicating a role of nNOS in neurovascular coupling. Urethane anesthesia is suitab le for future epileptological experiments. Our findings demonstrate that NO contributes to the hemodynamic response during brain activation., C. Brožíčková, J. Otáhal., and Obsahuje bibliografii a bibliografické odkazy
Abundant evidence indicates that ATP and adenosine act as neurotransmitters or co-transmitters, influencing nerve cell physiology in various ways. Therefore, regulation of ATP-metabolizing enzymes is essential for the normal development and function of neuronal tissue. In the present study we have examined the effect of gonadal (OVX) or adrenal (ADX) steroid hormone deprivation on the activity and expression of synaptic membrane ecto-ATPase in three extrahypothalamic brain areas of female rats, primarily not associated with reproductive function. It was shown that OVX significantly increased ecto-ATPase activity and the relative abundance of this enzyme in the hippocampal (Hip) and caudate nucleus (CN), but not in brain stem (BS) membrane preparations. ADX was followed by an upregulation of the enzyme activity and its relative abundance in all the brain areas investigated. The highest enzyme activity and the most profound effects of OVX and ADX were detected in the CN. The results obtained indicate that ADX and OVX upregulate the expression of ecto-ATPase, potentiating the production of adenosine in synaptic cleft thus modulating the activity of numerous neurotransmitter systems in distinct areas of the CNS., N. Nedeljkovic, V. Djordjevic, A. Horvat, G. Nikezic, D.T. Kanazir., and Obsahuje bibliografii