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1. Are embryonal neurones used for transplantation "sufficiently immature"?

Creator:
Pokorný, J., Langmeier, M., and Trojan, S.
Type:
article, model:article, and TEXT
Subject:
hippocampus, embryonal neurones, neuronal suspension, and dendritic development
Language:
English
Description:
Live neuronal suspensions, prepared from the hippocampal region of donors aged 20 embryonal days, were observed in the Nomarski Differential Interference Contrast. Many neurones displayed profiles, resembling dendrites or axons and both principal hippocampal neurones (pyramidal and granular cells) were identified. For transplantation studies, donors of a younger embryonal age are thus recommended.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

2. Changes in the density of nitrergic neurons in the hippocampus of rats following kainic acid and melatonin administration

Creator:
Jain, A., Sharma, D., Suhalka, P., Sukhwal, P., and Bhatnagar, M.
Type:
article, články, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, fyziologie člověka, human physiology, NADPH-diaphorase, kainic acid, melatonin, nitric oxide, hippocampus, 14, and 612
Language:
English
Description:
Nitric oxide (NO) may play a role in the pathophysiology of excitotoxicity. It is also possible that increase in Ca2+ overload and NO-mediated events are involved in neuronal loss during excitotoxicity. Using nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemistry, we have investigated the effects of melatonin on NADPH-d positive hippocampal neurons after kainic acid (KA) induced excitotoxicity in female rats of Wistar strain. Cytosolic Ca2+ (free calcium) in all the respective experimental groups was also studied. Kainic acid was administered, with a single dose of 10 mg/kg/bw (body weight) to the animals. KA treated rats were given melatonin at a dose of 20 mg/kg/bw (for 14 day). On the last day of treatment, animals were transcardially perfused with 4 % paraformaldehyde under deep thiopental anaesthesia. Cryostat sections (20 µm) were cut and stained for NADPH-d positive neurons. KA exposed animals showed a significantly increased number of NADPH-d positive neurons in the dorsal and ventral blade of the dentate gyrus (DG), hilus, CA1 and CA3 area of hippocampus, with a parallel increase in intracellular free Ca2+ ion concentration, as compared to the control group. KA + melatonin-treated animal groups showed reduced number of NADPH-d positive neurons in DG, hilus, CA1 and CA3 areas and a decline in cytosolic Ca2+ concentration, as compared to KA treated group. Our study suggests that the enhanced levels of cytosolic Ca2+ and nitric oxide (NO) play an important role in kainate induced excitotoxicity. Inhibition of NO production may be another means whereby melatonin can reduce oxidative damage and seems to play important role in neuroprotection., A. Jain, ... [et al.]., and Obsahuje seznam literatury
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

3. Changes of hippocampal neurons after perinatal exposure to ethanol

Creator:
Milotová, M., Vladimír Riljak, Kateřina Jandová, Jana Bortelová, Dana Marešová, Jaroslav Pokorný, and Miloš Langmeier
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, fyziologie, ethanol, neurodegenerace, apoptóza, physiology, neurodegeneration, apoptosis, hippocampus, dentate gyrus, 14, and 612
Language:
English
Description:
The effect of ethanol on the structural development of the central nervous system was studied in offspring of Wistar rats, drinking 20 % ethanol during pregnancy and till the 28th day of their postnatal life. The structural changes in the hippocampus and dentate gyrus were analyzed at the age of 18, 35 and 90 days. A lower width of pyramidal and granular cell layers, cell extinction and fragmentation of numerous nuclei were found in all experimental animals compared to control animals. The extent of neural cell loss was similar in all monitored areas and in all age groups. At the age of 18 and 35 days, the degenerating cells were observed in the CA1 and CA3 area of the hippocampus and in the ventral and dorsal blade of the dentate gyrus. Numerous glial cells replaced the neuronal population of this region. Some degenerating cells with fragmented nuclei were observed at the age of 90 days. Our experiments confirmed the vulnerability of the developing central nervous system by ethanol intake during the perinatal period and revealed a long-lasting degeneration process in the hippocampus and dentate gyrus., M. Milotová, V. Riljak, K. Jandová, J. Bortelová, D. Marešová, K. Pokorný, M. Langmeier., and Obsahuje bibliografii a bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

4. Changes of hippocampal noradrenergic capacity in stress condition

Creator:
Gavrilović, L., Popović, N., Stojiljković, V., Pejić, S., Todorović, A., Pavlović, I., and Pajović, S. B.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
chronic restraint stress, noradrenaline, hippocampus, and rats
Language:
English
Description:
This study aimed to investigate the effects of chronic restraint stress (CRS) on the protein levels of dopamine-β-hydroxylase (DBH), noradrenaline transporter (NET), vesicular monoamine transporter 2 (VMAT2) and brain-derived neurotrophic factor (BDNF), as well as the concentration of noradrenaline (NA) in the rat hippocampus. The investigated parameters were quantified by Western blot analyses and ELISA kits. We found that CRS increased the protein levels of DBH by 30 %, VMAT2 by 11 %, BDNF by 11 % and the concentration of NA by 104 %, but decreased the protein levels of NET by 16 % in the hippocampus of chronically stressed rats. The molecular mechanisms by which CRS increased the hippocampal NA level are an important adaptive phenomenon of the noradrenergic system in the stress condition.
Rights:
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5. Distinct effect of stress on 11β-hydroxysteroid dehydrogenase type 1 and corticosteroid receptors in dorsal and ventral hippocampus

Creator:
Ergang, P., Kuželová, A., Matúš Soták, Klusoňová, P., Makal, J., and Jiří Pácha
Format:
print
Type:
article, články, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, stres (fyziologie), kortikosteroidy, stress (physiology), corticosteroids, 11β-hydroxysteroid dehydrogenase, hippocampus, corticosteroid receptors, 14, and 612
Language:
English
Description:
Multiple lines of evidence suggest the participation of the hippocampus in the feedback inhibition of the hypothalamus- pituitary-adrenal axis during stress response. This inhibition is mediated by glucocorticoid feedback due to the sensitivity of the hippocampus to these hormones. The sensitivity is determined by the expression of glucocorticoid (GR) and mineralocorticoid (MR) receptors and 11 β -hydroxysteroid dehydrogenase type 1 (11HSD1), an enzyme that re gulates the conversion of glucocorticoids from inactive to active form. The goal of our study was to assess the effect of stress on the expression of 11HSD1, GR and MR in the ventral and dorsal region of the CA1 hippocampus in three different rat strains with diverse responses to stress: Fisher 344, Lewis and Wistar. Stress stimulated 11HSD1 in the ventral but not dorsal CA1 hippocampus of Fisher 344 but not Lewis or Wistar rats. In contrast, GR expression following stress was decreased in the dorsal but not ventral CA1 hippocampus of all three strains. MR expression was not changed in either the dorsal or ventral CA1 region. These results indicate that (1) depending on the strain, stress stimulates 11HSD1 in the ventral hippocampus, which is known to be involved in stress and emotion reactions whereas (2) independent of strain, stress inhibits GR in the dorsal hippocampus, which is predominantly involved in cognitive functions., P. Ergang ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

6. Downregulation of HCN1 channels in hippocampus and prefrontal cortex in methamphetamine re-exposed mice with enhanced working memory

Creator:
Zhou, M. , Lin, K. , Si, Y. , Ru, Q. , Chen, L. , Xiao, H. , and Li, C.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
methamphetamine, working memory, HCN channels, hippocampus, and prefrontal cortex
Language:
English
Description:
The hyperpolarization-activated cyclic-nucleotide-gated non-selective cation (HCN) channels play a potential role in the neurological basis underlying drug addiction. However, little is known about the role of HCN channels in methamphetamine (METH) abuse. In the present study, we examined the changes in working memory functions of METH re-exposed mice through Morris water maze test, and investigated the protein expression of HCN1 channels and potential mechanisms underlying the modulation of HCN channels by Western blotting analysis. Mice were injected with METH (1 mg/kg, i.p.) once per day for 6 consecutive days. After 5 days without METH, mice were re-exposed to METH at the same concentration. We found that METH re-exposure caused an enhancement of working memory, and a decrease in the HCN1 channels protein expression in both hippocampus and prefrontal cortex. The phosphorylated extracellular regulated protein kinase 1/2 (p-ERK1/2), an important regulator of HCN channels, was also obviously reduced in hippocampus and prefrontal cortex of mice with METH re-exposure. Meanwhile, acute METH exposure did not affect the working memory function and the protein expressions of HCN1 channels and p-ERK1/2. Overall, our data firstly showed the aberrant protein expression of HCN1 channels in METH re-exposed mice with enhanced working memory, which was probably related to the down-regulation of p-ERK1/2 protein expression.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

7. Early postnatal hypoxia induces behavioral deficits but not morphological damage in the hippocampus in adolescent rats

Creator:
Riljak, Vladimír, Laštůvka, Zdeněk, Mysliveček, Jaromír, Borbélyová, Veronika, and Otáhal, Jakub
Format:
počítač and online zdroj
Type:
model:article and TEXT
Subject:
behavior, hippocampus, short-term hypoxia, open field test, and sex differences
Language:
English
Description:
Hypoxia is one of the major pathological factors affecting brain function. The aim of the present study was to describe the effect of neonatal hypobaric hypoxia on the behavior of rats and to analyze its effect on hippocampal neurodegeneration. Hypobaric hypoxia at a simulated altitude of 9000 m was induced for one hour in neonatal rat pups (PND7 and PND9) of both sexes. Subsequently, the rats underwent behavioral testing on PND25 and PND35 using a LABORAS apparatus to assess spontaneous behavior. Hypoxia did not cause any morphological damage in the hippocampus of rats. However, hypoxia on PND7 led to less horizontal locomotor activity both in males (on PND25) and females (on PND35). Hypoxia on PND9 led to higher rearing in females on PND25. Hypoxic males exhibited higher grooming activity, while females lower grooming activity on PND35 following hypoxia induced on PND7. In females, hypoxia on PND9 resulted in higher grooming activity on PND25. Sex differences in the effect of hypoxia were observed on PND35, when hypoxic males compared to hypoxic females displayed more locomotor, rearing and grooming activity. Our data suggest that hypoxia on PND7 versus PND9 differently affects locomotion and grooming later in adolescence and these effects are sex-dependent.
Rights:
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8. Ecto-ATPase and ecto-ATP-diphosphohydrolase are co-localized in rat hippocampal and caudate nucleus synaptic plasma membranes

Creator:
Nedeljkovic, N., Banjac, A., Horvat, A., Stojiljkovic, M., and Nikezic, G.
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, Ecto-ATPase, ecto-ATPhydroxylase, hippocampus, caudate nucleus, rat, 14, and 612
Language:
English
Description:
Enzymes that hydrolyze extracellular ATP, i.e. ecto-ATPase and ecto-ATP diphosphohydrolase (ATPDase), can be differentiated by ability of the latter to hydrolyze ADP and by slightly different kinetic properties of the two enzymes. Synaptic plasma membrane fractions isolated from rat hippocampus and caudate nucleus exhibit ADP-hydrolyzing activity, as revealed by the enzyme assay, and the presence of ecto-ATPase protein, as revealed by immunological identification on Western blot. These findings indicate that both enzymes are co-expressed in the synaptic membrane compartment of hippocampal and caudate nucleus neurons. Kinetic analysis was performed to determine the relative contribution of each enzyme to the total ATP-hydrolyzing activity, while an inhibition study was carried out in order to exclude the interference of other nonspecific ATPase and phosphatase activities. Based on the kinetic properties, sensitivity to inhibitors and VATP/VADP ratio of about 2, we concluded that a substantial portion of ATP-hydrolyzing activity in both synaptic membrane preparations can be ascribed to the catalytic action of ATPDase. On the other hand, the highest catalytic efficacy when ATP is the substrate and the greater abundance of ecto-ATPase protein in caudate nucleus preparation suggest that the relative contribution of ecto-ATPase to the total ATP-hydrolyzing activity in the caudate nucleus is higher than in the hippocampus., N. Nedeljkovic, A. Banjac, A. Horvat, M. Stojiljkovic, G. Nikezic., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

9. Effect of endothelin-1 on the excitability of rat cortical and hippocampal slices in vitro

Creator:
Renata Konopková, Vilagi, I., Borbely, S., Hana Kubová, and Otáhal, J.
Type:
article, články, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, fyziologie člověka, human physiology, endothelin-1, excitability, hippocampus, somatosensory cortex, rat, epileptogenesis, 14, and 612
Language:
English
Description:
Endothelin-1 (ET-1) is a neuroactive protein produced in most brain cell types and participates in regulation of cerebral blood flow and blood pressure. In addition to its vascular effects, ET-1 affects synaptic and nonsynaptic neuronal and glial functions. Direct application of ET-1 to the hippocampus of immature rats results in cerebral ischemia, acute seizures, and epileptogenesis. Here, we investigated whether ET-1 itself modifies the excitability of hippocampal and cortical circuitry and whether acute seizures observed in vivo are due to nonvascular actions of ET-1. We used acute hippocampal and cortical slices that were preincubated with ET-1 (20 µM) for electrophysiological recordings. None of the slices preincubated with ET-1 exhibited spontaneous epileptic activity. The slope of the stimulus intensity-evoked response (input-output) curve and shape of the evoked response did not differ between ET-1-pretreated and control groups, suggesting no changes in excitability after ET-1 treatment. The threshold for eliciting an evoked response was not significantly increased in either hippocampal or cortical regions when pretreated with ET-1. Our data suggest that acute seizures after intrahippocampal application of ET-1 in rats are likely caused by ischemia rather than by a direct action of ET-1 on brain tissue., R. Konopková ... [et al.]., and Obsahuje seznam literatury
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

10. Effect of GABAB receptor agonist SKF97541 on cortical and hippocampal epileptic afterdischarges

Creator:
Fábera, P.
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, GABAB receptor, agonist, hippocampus, cortex, epileptic afterdischarges, rat, 14, and 612
Language:
English
Description:
Activation of GABAB receptors leads to longer inhibitory postsynaptic potentials than activation of GABAA receptors. Therefore GABAB receptors may be a target for anticonvulsant therapy. The present study examined possible effects of GABAB receptor agonist SKF97541 on cortical and hippocampal epileptic afterdischarges (ADs). Epileptic ADs elicited by electrical stimulation of sensorimotor cortex or dorsal hippocampus were studied in adult male Wistar rats. Stimulation series were applied 6 times with 10- or 20-min interval. Either interval was efficient for reliable elicitation of cortical ADs but stimulation at 10-min intervals did not reliably elicit hippocampal ADs, many stimulations were without effect. SKF97541 in dose 1 mg/kg significantly prolonged cortical ADs. Duration of hippocampal ADs was not significantly changed by either dose of SKF97541 in spite of a marked myorelaxant effect of the higher dose. Our present data demonstrated that neither cortical nor hippocampal ADs in adult rats were suppressed by GABAB receptor agonist SKF97541. Proconvulsant effect on cortical ADs indicates a different role in these two brain structures. In addition, duration of refractory period for electrically-induced ADs in these two structures in adult rats is different., P. Fábera, P. Mares., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public