Gábor Juhász - Academia.edu (original) (raw)

Papers by Gábor Juhász

szakdolgozat, 2023

Napjaink egyik égető problémája a közlekedés által felhasznált véges fosszilis energia hozzáférhe... more Napjaink egyik égető problémája a közlekedés által felhasznált véges fosszilis energia hozzáférhetősége, valamint a hozzá kapcsolódó környezetszennyezés és szén-dioxid kibocsátás. A dolgozat fenntarthatóság oldaláról közelíti meg a problémát, azon belül is az elektromos technológiára való átállás lehetőségét, technológiai és gazdasági megközelítéssel.

Brain research bulletin, Jan 10, 2015

We showed previously that the number of spike-wave discharges (SWDs) was increased after intraper... more We showed previously that the number of spike-wave discharges (SWDs) was increased after intraperitoneal (i.p.) injection of lipopolysaccharide (LPS), inosine (Ino) and muscimol alone whereas i.p. guanosine (Guo), uridine (Urd), bicuculline, theophylline and (+)-5-methyl-10,11-dihydro-5H-dibenzo(a,d)cyclohepten-5,10-imine maleate (MK-801) alone decreased the SWD number in Wistar Albino Glaxo/Rijswijk (WAG/Rij) rats. These drugs may exert their effects on absence epileptic activity mainly via proinflammatory cytokines-evoked increase in cortical excitability (such as LPS), GABAergic system (LPS, Ino, Urd, muscimol and bicuculline), glutamatergic system (LPS, Guo and MK-801) and adenosinergic system (LPS, Ino, Guo, Urd and theophylline). Both GABAergic system and glutamatergic system are involved in the pathomechanism of absence epilepsy, the LPS-evoked increase in absence epileptic activity and the pro- or antiepileptic effects of non-adenosine (non-Ado) nucleosides Ino, Guo and Urd....

Electroencephalography and Clinical Neurophysiology, 1976

Autophagy, 2013

Defining new roles and mechanisms of autophagy, mainly in Drosophila. Model system Drosophila and... more Defining new roles and mechanisms of autophagy, mainly in Drosophila. Model system Drosophila and cultured insect cells.

Neuroscience Letters, 1989

Neuroscience Letters, 2007

Antiepileptic and network inhibitory actions of Q5 (2-methyl-4-oxo-3H-quinazoline-3-acetyl piperi... more Antiepileptic and network inhibitory actions of Q5 (2-methyl-4-oxo-3H-quinazoline-3-acetyl piperidine) have recently been described in hippocampal slices. Here we present evidence on the in vivo antiabsence effect of Q5. All doses of Q5 tested (0.3 mg/kg, 0.9 mg/kg, 2.8 mg/kg) decreased the number, but not the duration and the frequency of absence spike-wave discharges (SWDs) in freely moving WAG/Rij rats. In vivo network inhibitory action of Q5 was monitored by following c-fos expression in different brain areas of Wistar rats. Significant depletion of c-fos expression was observed after single or repeated injections of Q5 (2.8 mg/kg and 2 × 2.8 mg/kg) in various brain areas, including hypothalamic paraventricular nucleus, medial amygdaloid nucleus, piriform cortex, somatosensory cortex, periventricular thalamic nucleus and periaqueductal central gray. Thus, our in vivo results demonstrate that in addition to the prevention of absence seizures, Q5 effectively suppresses neuronal activation in various stress-and pain-sensitive brain areas.

Neuron, 2009

Several aspects of perception, particularly those pertaining to vision, are closely linked to the... more Several aspects of perception, particularly those pertaining to vision, are closely linked to the occipital alpha (a) rhythm. However, how the a rhythm relates to the activity of neurons that convey primary visual information is unknown. Here we show that in behaving cats, thalamocortical neurons in the lateral geniculate nucleus (LGN) that operate in a conventional relay-mode form two groups where the cumulative firing is subject to a cyclic suppression that is centered on the negative a rhythm peak in one group and on the positive peak in the other. This leads to an effective temporal framing of relay-mode output and results from phasic inhibition from LGN interneurons, which in turn are rhythmically excited by thalamocortical neurons that exhibit high-threshold bursts. These results provide a potential cellular substrate for linking the a rhythm to perception and further underscore the central role of inhibition in controlling spike timing during cognitively relevant brain oscillations.

Neurochemistry International, 2010

Journal of Neuroscience Methods, 2005

There is an increasing attention paid for nucleoside metabolism and changes of nucleoside concent... more There is an increasing attention paid for nucleoside metabolism and changes of nucleoside concentrations in human brain because of its pathological and physiological relevance. In order to determine the post mortem degradation of nucleosides and nucleoside metabolites, the concentrations of four nucleosides and three nucleobases were measured in rat and neurosurgical human cerebral cortical samples with 30 s to 24 h post mortem delay. Adenosine degradation coefficient (a multiplying factor for calculating concentrations of investigated substances for the living state) was 0.886 for human brain at 2 h post mortem time, while it was 1.976 for rats. Hypoxanthine, an adenosine degradation product had coefficients 0.564 for human brain and 0.812 for the rat brain. We provide data and degradation coefficients for the concentrations of adenosine, guanosine, inosine, uridine, uracil, hypoxanthine and xanthine with 2, 4, 6 and 24 h post mortem delay. We also report a method how to validate human neurosurgical brain samples in terms of sample preparation and statistical analysis.

Journal of Neural Transmission, 2010

Antagonising the NMDA (N-methyl-D: -aspartate) receptor complex is a widely hypothesised therapeu... more Antagonising the NMDA (N-methyl-D: -aspartate) receptor complex is a widely hypothesised therapeutic approach in several neurodegenerative conditions, such as Alzheimer's disease. Memantine, a moderate affinity uncompetitive NMDA receptor antagonist, has been in clinical use for several years and numerous experimental data support its NMDA receptor blocking effects. It has recently been reported in transfected HEK293T cells that physiological concentrations of Mg(2+) may impart partial NMDA receptor subtype selectivity and weaken the overall inhibitory actions of memantine in NMDA receptor-mediated cellular events. In the present study, we set out to investigate the effect of intravenously applied memantine on iontophoresed NMDA-evoked firing of hippocampal CA1 neurons using in vivo conditions. Cumulative doses of memantine in the rat (4, 8 and 16 mg/kg i.v.) caused the firing rate to decrease in a dose-dependent manner to 77 ± 7, 58 ± 8 and 34 ± 12% of control, respectively, while saline application had no significant effect. We show that therapeutic doses of memantine are able to antagonize NMDA receptor-mediated activity in the principal cells of the hippocampus in vivo, i.e. in the presence of physiological concentrations of Mg(2+).

International Journal of Psychophysiology, 2005

It has long been known that readers of this page will move their eyes from one fixation to the ne... more It has long been known that readers of this page will move their eyes from one fixation to the next two to four times per second. It follows from this fact that each fixation triggers a unique optic nerve volley lasting up to 300 ms that contains all the information the retina processes between fixations. Here we give such volleys a name (Retinal Functional Unit, RFU) and use human subjects and interstimulus interval (ISI) experiments to define some of their properties. We report that RFUs can be dissected into an initial fraction that reaches the cortex and a later fraction that may not, depending on the ISI between successive stimuli. During the dissection process the perceptions of the stimuli change in an orderly way, such that successive thresholds of ''twoness'', color, and duration are reached as a function of increasing ISI. We conclude that volleys from the tens or hundreds of thousands of active axons contained in every RFU exit the retina in a precisely determined temporal order, and add this conclusion to three others for which we have already published the supporting data. 1) The mammalian retina normally takes about 300 ms to process a visual stimulus. 2) The ca. 300 ms end product, an RFU, contains in neuronal form all the photochemical information acquired during one fixation. 3) These information-rich volleys reach the cortex with little or no change thanks to monosynaptic transfer in the thalamus.

European Journal of Social Quality, 2006

This paper hypothesises that public support for the economic and political transformation in east... more This paper hypothesises that public support for the economic and political transformation in east-central Europe in 1989 was fuelled by enthusiasm for the reception of the (west) European Social Model, where the capitalist mode of production was combined with a high degree of social protection. In the first part of the article the author identifies the basic values of and the challenges to the European Social Model. Them he analyses the impact of the European Union on the transformation of east-central European social policy in the 1990s, and concludes that the negotiations concerning the accession of post-communist east-central European countries to the EU hardly contributed to the reception of the core values of the European Social Model in the new member states. Giving an overview of he social situation in the accession countries, the third part of the article calls the reader's attention to the alarming differences regarding the quality of life between the EU Fifteen and the new member states. In the final part, the author raises questions about the European Union's capacity to preserve the European Social Model, taking reactions of the members states to post-enlargement fears of social gaps between the east and west of Europe into consideration.

Epilepsy Research, 2010

The noradrenergic and serotonergic system may have a role in modulation of absence seizures. We i... more The noradrenergic and serotonergic system may have a role in modulation of absence seizures. We investigated whether the single injection of monoamine reuptake inhibitor clomipramine has an acute effect on spike-wave discharge (SWD) activity in Wistar Albino Glaxo/Rijswijk (WAG/Rij) rats. We injected a single dose of 20 or 50 mg/kg clomipramine intraperitoneally into WAG/Rij rats and measured the incidence and duration of SWD episodes for 4h after injection. The changes in SWDs were compared to the preceding 5-day average control level. The 20 mg/kg clomipramine significantly increased the incidence of SWDs in the first measured hour while the 50 mg/kg dose significantly increased the incidence and duration of SWDs in the whole measured 4-h period. Clomipramine, by acutely elevating synaptic monoamine levels, could exacerbate absence seizures.

Current Biology, 2007

Background: To survive starvation and other forms of stress, eukaryotic cells undergo a lysosomal... more Background: To survive starvation and other forms of stress, eukaryotic cells undergo a lysosomal process of cytoplasmic degradation known as autophagy. Autophagy has been implicated in a number of cellular and developmental processes, including cell-growth control and programmed cell death. However, direct evidence of a causal role for autophagy in these processes is lacking, resulting in part from the pleiotropic effects of signaling molecules such as TOR that regulate autophagy. Here, we circumvent this difficulty by directly manipulating autophagy rates in Drosophila through the autophagy-specific protein kinase Atg1. Results: We find that overexpression of Atg1 is sufficient to induce high levels of autophagy, the first such demonstration among wild-type Atg proteins. In contrast to findings in yeast, induction of autophagy by Atg1 is dependent on its kinase activity. We find that cells with high levels of Atg1-induced autophagy are rapidly eliminated, demonstrating that autophagy is capable of inducing cell death. However, this cell death is caspase dependent and displays DNA fragmentation, suggesting that autophagy represents an alternative induction of apoptosis, rather than a distinct form of cell death. In addition, we demonstrate that Atg1-induced autophagy strongly inhibits cell growth and that Atg1 mutant cells have a relative growth advantage under conditions of reduced TOR signaling. Finally, we show that Atg1 expression results in negative feedback on the activity of TOR itself. Conclusions: Our results reveal a central role for Atg1 in mounting a coordinated autophagic response and demonstrate that autophagy has the capacity to induce cell death. Furthermore, this work identifies autophagy as a critical mechanism by which inhibition of TOR signaling leads to reduced cell growth.

Clinical Biochemistry, 1997

Cellular and Molecular Neurobiology, 2006

1. Nucleosides potentially participate in the neuronal functions of the brain. However, their dis... more 1. Nucleosides potentially participate in the neuronal functions of the brain. However, their distribution and changes in their concentrations in the human brain is not known. For better understanding of nucleoside functions, changes of nucleoside concentrations by age and a complete map of nucleoside levels in the human brain are actual requirements. 2. We used post mortem human brain samples in the experiments and applied a recently modified HPLC method for the measurement of nucleosides. To estimate concentrations and patterns of nucleosides in alive human brain we used a recently developed reverse extrapolation method and multivariate statistical analyses. 3. We analyzed four nucleosides and three nucleobases in human cerebellar, cerebral cortices and in white matter in young and old adults. Average concentrations of the 308 samples investigated (mean ± SEM) were the following (pmol/mg wet tissue weight):

Brain, Behavior, and Immunity, 2014

Peripheral injection of bacterial lipopolysaccharide (LPS) facilitates 8-10 Hz spike-wave dischar... more Peripheral injection of bacterial lipopolysaccharide (LPS) facilitates 8-10 Hz spike-wave discharges (SWD) characterizing absence epilepsy in WAG/Rij rats. It is unknown however, whether peripherally administered LPS is able to alter the generator areas of epileptic activity at the molecular level. We injected 1 mg/kg dose of LPS intraperitoneally into WAG/Rij rats, recorded the body temperature and EEG, and examined the protein expression changes of the proteome 12 h after injection in the frontoparietal cortex and thalamus. We used fluorescent two-dimensional differential gel electrophoresis to investigate the expression profile. We found 16 differentially expressed proteins in the fronto-parietal cortex and 35 proteins in the thalamus. It is known that SWD genesis correlates with the transitional state of sleep-wake cycle thus we performed meta-analysis of the altered proteins in relation to inflammation, epilepsy as well as sleep. The analysis revealed that all categories are highly represented by the altered proteins and these protein-sets have considerable overlap. Protein network modeling suggested that the alterations in the proteome were largely induced by the immune response, which invokes the NFkB signaling pathway. The proteomics and computational analysis verified the known functional interplay between inflammation, epilepsy and sleep and highlighted proteins that are involved in their common synaptic mechanisms. Our physiological findings support the phenomenon that high dose of peripheral LPS injection increases SWD-number, modifies its duration as well as the sleep-wake stages and decreases body temperature.

Brain Research Bulletin, 2001

The vascularised rat retina could be one of the most useful experimental objects in visual neuros... more The vascularised rat retina could be one of the most useful experimental objects in visual neuroscience to understand human visual physiological and pathological processes. We report here on a new method of implantation for studying the visual system of freely moving rats that provides a rat model for simultaneous recording at corneal and cortical level and is stable enough to

szakdolgozat, 2023

Napjaink egyik égető problémája a közlekedés által felhasznált véges fosszilis energia hozzáférhe... more Napjaink egyik égető problémája a közlekedés által felhasznált véges fosszilis energia hozzáférhetősége, valamint a hozzá kapcsolódó környezetszennyezés és szén-dioxid kibocsátás. A dolgozat fenntarthatóság oldaláról közelíti meg a problémát, azon belül is az elektromos technológiára való átállás lehetőségét, technológiai és gazdasági megközelítéssel.

Brain research bulletin, Jan 10, 2015

We showed previously that the number of spike-wave discharges (SWDs) was increased after intraper... more We showed previously that the number of spike-wave discharges (SWDs) was increased after intraperitoneal (i.p.) injection of lipopolysaccharide (LPS), inosine (Ino) and muscimol alone whereas i.p. guanosine (Guo), uridine (Urd), bicuculline, theophylline and (+)-5-methyl-10,11-dihydro-5H-dibenzo(a,d)cyclohepten-5,10-imine maleate (MK-801) alone decreased the SWD number in Wistar Albino Glaxo/Rijswijk (WAG/Rij) rats. These drugs may exert their effects on absence epileptic activity mainly via proinflammatory cytokines-evoked increase in cortical excitability (such as LPS), GABAergic system (LPS, Ino, Urd, muscimol and bicuculline), glutamatergic system (LPS, Guo and MK-801) and adenosinergic system (LPS, Ino, Guo, Urd and theophylline). Both GABAergic system and glutamatergic system are involved in the pathomechanism of absence epilepsy, the LPS-evoked increase in absence epileptic activity and the pro- or antiepileptic effects of non-adenosine (non-Ado) nucleosides Ino, Guo and Urd....

Electroencephalography and Clinical Neurophysiology, 1976

Autophagy, 2013

Defining new roles and mechanisms of autophagy, mainly in Drosophila. Model system Drosophila and... more Defining new roles and mechanisms of autophagy, mainly in Drosophila. Model system Drosophila and cultured insect cells.

Neuroscience Letters, 1989

Neuroscience Letters, 2007

Antiepileptic and network inhibitory actions of Q5 (2-methyl-4-oxo-3H-quinazoline-3-acetyl piperi... more Antiepileptic and network inhibitory actions of Q5 (2-methyl-4-oxo-3H-quinazoline-3-acetyl piperidine) have recently been described in hippocampal slices. Here we present evidence on the in vivo antiabsence effect of Q5. All doses of Q5 tested (0.3 mg/kg, 0.9 mg/kg, 2.8 mg/kg) decreased the number, but not the duration and the frequency of absence spike-wave discharges (SWDs) in freely moving WAG/Rij rats. In vivo network inhibitory action of Q5 was monitored by following c-fos expression in different brain areas of Wistar rats. Significant depletion of c-fos expression was observed after single or repeated injections of Q5 (2.8 mg/kg and 2 × 2.8 mg/kg) in various brain areas, including hypothalamic paraventricular nucleus, medial amygdaloid nucleus, piriform cortex, somatosensory cortex, periventricular thalamic nucleus and periaqueductal central gray. Thus, our in vivo results demonstrate that in addition to the prevention of absence seizures, Q5 effectively suppresses neuronal activation in various stress-and pain-sensitive brain areas.

Neuron, 2009

Several aspects of perception, particularly those pertaining to vision, are closely linked to the... more Several aspects of perception, particularly those pertaining to vision, are closely linked to the occipital alpha (a) rhythm. However, how the a rhythm relates to the activity of neurons that convey primary visual information is unknown. Here we show that in behaving cats, thalamocortical neurons in the lateral geniculate nucleus (LGN) that operate in a conventional relay-mode form two groups where the cumulative firing is subject to a cyclic suppression that is centered on the negative a rhythm peak in one group and on the positive peak in the other. This leads to an effective temporal framing of relay-mode output and results from phasic inhibition from LGN interneurons, which in turn are rhythmically excited by thalamocortical neurons that exhibit high-threshold bursts. These results provide a potential cellular substrate for linking the a rhythm to perception and further underscore the central role of inhibition in controlling spike timing during cognitively relevant brain oscillations.

Neurochemistry International, 2010

Journal of Neuroscience Methods, 2005

There is an increasing attention paid for nucleoside metabolism and changes of nucleoside concent... more There is an increasing attention paid for nucleoside metabolism and changes of nucleoside concentrations in human brain because of its pathological and physiological relevance. In order to determine the post mortem degradation of nucleosides and nucleoside metabolites, the concentrations of four nucleosides and three nucleobases were measured in rat and neurosurgical human cerebral cortical samples with 30 s to 24 h post mortem delay. Adenosine degradation coefficient (a multiplying factor for calculating concentrations of investigated substances for the living state) was 0.886 for human brain at 2 h post mortem time, while it was 1.976 for rats. Hypoxanthine, an adenosine degradation product had coefficients 0.564 for human brain and 0.812 for the rat brain. We provide data and degradation coefficients for the concentrations of adenosine, guanosine, inosine, uridine, uracil, hypoxanthine and xanthine with 2, 4, 6 and 24 h post mortem delay. We also report a method how to validate human neurosurgical brain samples in terms of sample preparation and statistical analysis.

Journal of Neural Transmission, 2010

Antagonising the NMDA (N-methyl-D: -aspartate) receptor complex is a widely hypothesised therapeu... more Antagonising the NMDA (N-methyl-D: -aspartate) receptor complex is a widely hypothesised therapeutic approach in several neurodegenerative conditions, such as Alzheimer's disease. Memantine, a moderate affinity uncompetitive NMDA receptor antagonist, has been in clinical use for several years and numerous experimental data support its NMDA receptor blocking effects. It has recently been reported in transfected HEK293T cells that physiological concentrations of Mg(2+) may impart partial NMDA receptor subtype selectivity and weaken the overall inhibitory actions of memantine in NMDA receptor-mediated cellular events. In the present study, we set out to investigate the effect of intravenously applied memantine on iontophoresed NMDA-evoked firing of hippocampal CA1 neurons using in vivo conditions. Cumulative doses of memantine in the rat (4, 8 and 16 mg/kg i.v.) caused the firing rate to decrease in a dose-dependent manner to 77 ± 7, 58 ± 8 and 34 ± 12% of control, respectively, while saline application had no significant effect. We show that therapeutic doses of memantine are able to antagonize NMDA receptor-mediated activity in the principal cells of the hippocampus in vivo, i.e. in the presence of physiological concentrations of Mg(2+).

International Journal of Psychophysiology, 2005

It has long been known that readers of this page will move their eyes from one fixation to the ne... more It has long been known that readers of this page will move their eyes from one fixation to the next two to four times per second. It follows from this fact that each fixation triggers a unique optic nerve volley lasting up to 300 ms that contains all the information the retina processes between fixations. Here we give such volleys a name (Retinal Functional Unit, RFU) and use human subjects and interstimulus interval (ISI) experiments to define some of their properties. We report that RFUs can be dissected into an initial fraction that reaches the cortex and a later fraction that may not, depending on the ISI between successive stimuli. During the dissection process the perceptions of the stimuli change in an orderly way, such that successive thresholds of ''twoness'', color, and duration are reached as a function of increasing ISI. We conclude that volleys from the tens or hundreds of thousands of active axons contained in every RFU exit the retina in a precisely determined temporal order, and add this conclusion to three others for which we have already published the supporting data. 1) The mammalian retina normally takes about 300 ms to process a visual stimulus. 2) The ca. 300 ms end product, an RFU, contains in neuronal form all the photochemical information acquired during one fixation. 3) These information-rich volleys reach the cortex with little or no change thanks to monosynaptic transfer in the thalamus.

European Journal of Social Quality, 2006

This paper hypothesises that public support for the economic and political transformation in east... more This paper hypothesises that public support for the economic and political transformation in east-central Europe in 1989 was fuelled by enthusiasm for the reception of the (west) European Social Model, where the capitalist mode of production was combined with a high degree of social protection. In the first part of the article the author identifies the basic values of and the challenges to the European Social Model. Them he analyses the impact of the European Union on the transformation of east-central European social policy in the 1990s, and concludes that the negotiations concerning the accession of post-communist east-central European countries to the EU hardly contributed to the reception of the core values of the European Social Model in the new member states. Giving an overview of he social situation in the accession countries, the third part of the article calls the reader's attention to the alarming differences regarding the quality of life between the EU Fifteen and the new member states. In the final part, the author raises questions about the European Union's capacity to preserve the European Social Model, taking reactions of the members states to post-enlargement fears of social gaps between the east and west of Europe into consideration.

Epilepsy Research, 2010

The noradrenergic and serotonergic system may have a role in modulation of absence seizures. We i... more The noradrenergic and serotonergic system may have a role in modulation of absence seizures. We investigated whether the single injection of monoamine reuptake inhibitor clomipramine has an acute effect on spike-wave discharge (SWD) activity in Wistar Albino Glaxo/Rijswijk (WAG/Rij) rats. We injected a single dose of 20 or 50 mg/kg clomipramine intraperitoneally into WAG/Rij rats and measured the incidence and duration of SWD episodes for 4h after injection. The changes in SWDs were compared to the preceding 5-day average control level. The 20 mg/kg clomipramine significantly increased the incidence of SWDs in the first measured hour while the 50 mg/kg dose significantly increased the incidence and duration of SWDs in the whole measured 4-h period. Clomipramine, by acutely elevating synaptic monoamine levels, could exacerbate absence seizures.

Current Biology, 2007

Background: To survive starvation and other forms of stress, eukaryotic cells undergo a lysosomal... more Background: To survive starvation and other forms of stress, eukaryotic cells undergo a lysosomal process of cytoplasmic degradation known as autophagy. Autophagy has been implicated in a number of cellular and developmental processes, including cell-growth control and programmed cell death. However, direct evidence of a causal role for autophagy in these processes is lacking, resulting in part from the pleiotropic effects of signaling molecules such as TOR that regulate autophagy. Here, we circumvent this difficulty by directly manipulating autophagy rates in Drosophila through the autophagy-specific protein kinase Atg1. Results: We find that overexpression of Atg1 is sufficient to induce high levels of autophagy, the first such demonstration among wild-type Atg proteins. In contrast to findings in yeast, induction of autophagy by Atg1 is dependent on its kinase activity. We find that cells with high levels of Atg1-induced autophagy are rapidly eliminated, demonstrating that autophagy is capable of inducing cell death. However, this cell death is caspase dependent and displays DNA fragmentation, suggesting that autophagy represents an alternative induction of apoptosis, rather than a distinct form of cell death. In addition, we demonstrate that Atg1-induced autophagy strongly inhibits cell growth and that Atg1 mutant cells have a relative growth advantage under conditions of reduced TOR signaling. Finally, we show that Atg1 expression results in negative feedback on the activity of TOR itself. Conclusions: Our results reveal a central role for Atg1 in mounting a coordinated autophagic response and demonstrate that autophagy has the capacity to induce cell death. Furthermore, this work identifies autophagy as a critical mechanism by which inhibition of TOR signaling leads to reduced cell growth.

Clinical Biochemistry, 1997

Cellular and Molecular Neurobiology, 2006

1. Nucleosides potentially participate in the neuronal functions of the brain. However, their dis... more 1. Nucleosides potentially participate in the neuronal functions of the brain. However, their distribution and changes in their concentrations in the human brain is not known. For better understanding of nucleoside functions, changes of nucleoside concentrations by age and a complete map of nucleoside levels in the human brain are actual requirements. 2. We used post mortem human brain samples in the experiments and applied a recently modified HPLC method for the measurement of nucleosides. To estimate concentrations and patterns of nucleosides in alive human brain we used a recently developed reverse extrapolation method and multivariate statistical analyses. 3. We analyzed four nucleosides and three nucleobases in human cerebellar, cerebral cortices and in white matter in young and old adults. Average concentrations of the 308 samples investigated (mean ± SEM) were the following (pmol/mg wet tissue weight):

Brain, Behavior, and Immunity, 2014

Peripheral injection of bacterial lipopolysaccharide (LPS) facilitates 8-10 Hz spike-wave dischar... more Peripheral injection of bacterial lipopolysaccharide (LPS) facilitates 8-10 Hz spike-wave discharges (SWD) characterizing absence epilepsy in WAG/Rij rats. It is unknown however, whether peripherally administered LPS is able to alter the generator areas of epileptic activity at the molecular level. We injected 1 mg/kg dose of LPS intraperitoneally into WAG/Rij rats, recorded the body temperature and EEG, and examined the protein expression changes of the proteome 12 h after injection in the frontoparietal cortex and thalamus. We used fluorescent two-dimensional differential gel electrophoresis to investigate the expression profile. We found 16 differentially expressed proteins in the fronto-parietal cortex and 35 proteins in the thalamus. It is known that SWD genesis correlates with the transitional state of sleep-wake cycle thus we performed meta-analysis of the altered proteins in relation to inflammation, epilepsy as well as sleep. The analysis revealed that all categories are highly represented by the altered proteins and these protein-sets have considerable overlap. Protein network modeling suggested that the alterations in the proteome were largely induced by the immune response, which invokes the NFkB signaling pathway. The proteomics and computational analysis verified the known functional interplay between inflammation, epilepsy and sleep and highlighted proteins that are involved in their common synaptic mechanisms. Our physiological findings support the phenomenon that high dose of peripheral LPS injection increases SWD-number, modifies its duration as well as the sleep-wake stages and decreases body temperature.

Brain Research Bulletin, 2001

The vascularised rat retina could be one of the most useful experimental objects in visual neuros... more The vascularised rat retina could be one of the most useful experimental objects in visual neuroscience to understand human visual physiological and pathological processes. We report here on a new method of implantation for studying the visual system of freely moving rats that provides a rat model for simultaneous recording at corneal and cortical level and is stable enough to