Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    PSYCHOLOGICAL STRESS REDUCES CYCLIC 3′,5′-ADENOSINE MONOPHOSPHATE LEVELS IN THE CEREBRAL CORTEX OF CONSCIOUS RATS, AS DETERMINED BY A NEW CRYOGENIC METHOD OF RAPID TISSUE FIXATION (1978)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 30 (1978), S. 0 
    Details
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract— Cryoplates were implanted on the surface of the cortex in 32 chronic rat preparations. These devices were used both to freeze and to extract small samples of tissue. Coolant was circulated through each device by small flexible polyethylene tubes. Two series of experiments were performed. In the first, the animals were unrestrained and showed no behavioral signs of stress during the freeze fixation. The temperature responses of the cryoplates were very rapid (−632°C/s), and samples more than 1 mm thick were frozen and extracted within a few hundred ms following the onset of cooling. Each sample was analyzed for 3′.5′-adenosine monophosphate (cyclic AMP) and protein content. The results from the cryoplate group (25.6 ± 15.6pmol cyclic AMP/mg protein) were compared to those obtained from two other groups in which freeze fixation was produced by immersion in liquid nitrogen (13.6 ± 4.6pmol/mg protein) or decapitation into liquid nitrogen (18.6 + 7.6pmol/mg protein). In the second series of experiments, three types of stress (limb restraint, non-adaptation to the experimental situation, and moderate cutaneous electric shock) were induced separately in order to determine the influence of each on cortical levels of cyclic AMP. Control animals were highly adapted to the experimental situation, freely moving and not shocked. The samples from each of the stressed groups showed a statistically significant (P≤. 0.01) reduction in cyclic AMP in comparison with the level in the controls (control: 29.3 pmol/mg protein; restrained: 14.2pmol/mg protein; unadapted: 9.6pmol/mg protein; shocked: 7.1 pmol/mg protein). Thus, psychological and physical stress reduced cyclic AMP content in parietal cortex.Results from the second series of experiments suggest that the significantly higher mean and larger standard deviation of the cryoplate group in the first series are due to less psychological and physical stress being evoked by our method; different types of stress appear to account for the two different lower levels found in the immersion and decapitation groups. We believe that our method of cryogenic tissue fixation offers an improved approach to study of the neurochemical correlates of behavioral and neuroelectric events in the conscious animal.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1471-4159.1978.tb10773.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    CUTANEOUS SHOCK PRODUCES CORRELATED SHIFTS IN SLOW POTENTIAL AMPLITUDE AND CYCLIC 3′,5′-ADENOSINE MONOPHOSPHATE LEVEL IN THE PARIETAL CORTEX OF THE CONSCIOUS RAT (1978)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 30 (1978), S. 0 
    Details
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract— Fourteen animals each received 4 cutaneous shocks with an interval of 3–5 min between them. During a fifth trial 3–5 min later, eleven subjects received a fifth shock and then 3–30 s afterwards, as cerebral slow potentials developed in response to the stimulus, samples of parietal cortex were rapidly frozen and extracted by a cryoplate. Three baseline subjects received no shock at the time of the fifth trial and had their parietal tissue samples taken without the presence of slow potentials. A correlation coefficient of r=−0.77 (P 〈 0.01) was observed between the slow potential amplitude on the surface of the parietal cortex at the time of the sampling and the analyzed level of cyclic AMP in the underlying tissue. Five of the shocked animals whose samples were taken before the slow potentials increased significantly showed a tissue level of 11.1 ± 3.0 pmol cyclic AMP/mg protein. This level was significantly higher (P 〈 0.01) than that of the baseline animals (3.1 ± 2.0 pmol cyclic AMP/mg protein). The other six shocked animals who had developed large slow potentials manifested a cyclic AMP level that was not different from the baseline group. It is concluded that a reoccurring cutaneous shock results in the immediate increase in the level of cyclic AMP in the parietal cortex and that within 30 s this level decreases in proportion to the amplitude of the slow potential that develops in the same region.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1471-4159.1978.tb10774.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    ESTIMATION OF LEVELS OF SEROTONIN AND 5-HYDROXYINDOLES IN WHOLE BLOOD BY AN AUTOANALYTICAL PROCEDURE: OBSERVATIONS ON THE BLOOD-BRAIN BARRIER (1972)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 19 (1972), S. 0 
    Details
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract— We describe a method for the fluorometric determination of 5-hydroxyindoles in the physiological range of 0.010–1.30 μg/ml of whole blood by means of an autoanalytical procedure. Serotonin is dialysed free from haemolysed blood constituents and a complex between 5-HT and o-phthaldialdehyde is formed in the dialysand to provide a considerable increase over the native fluorescence of 5-HT in strong acid. The method has been evaluated and considered to be accurate for the continuous monitoring of levels of 5-HT in whole blood and for the determination of cerebral arteriovenous differences. The range of values for human patients with cerebrovascular disease was 0.09–0.34 μg/ml of whole blood. In experimental studies on the baboon the range was 0.538–1.28 μg/ml. A mean positive cerebral arteriovenous difference for 5-HT (and possibly other 5-hydroxyindoles) of 0.037 μg/ml was measured in 10 baboons. This finding suggests the possibility of physiological movement of 5-HT and 5-hydroxyindoles into brain across the blood-brain barrier.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1471-4159.1972.tb01428.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    EFFECT OF TRANSIENT ISCHEMIA ON MONOAMINE LEVELS IN THE CEREBRAL CORTEX OF GERBILS (1978)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 30 (1978), S. 0 
    Details
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract— Cortical monoamine changes during ischemic episodes of varied duration and their sequence of changes following cerebral reperfusion were studied in the gerbil. Forty-one percent of 280 animals exhibited signs of cerebral hemispheric ischemia (stroke) after unilateral common carotid artery occlusion. Norepinephrine (NE) levels decreased after 60 min in the occluded hemisphere of stroked animals but dopamine (DA) levels were unaltered. S-Hydroxytryptamine (5-HT) levels became bilaterally reduced in both stroked and non-stroked animals as soon as S min after occlusion.Upon reperfusion after periods of 30 or 60 min of occlusion there was a bilateral rebound increase of cortical NE and DA levels to well above control values in stroked and non-stroked animals. 5-HT levels remained reduced in both groups.Results suggest disorder of monoamine metabolism in ischemic brain which persists during the early reperfusion period, perhaps contributing to deficits in neurological function.Monoamine changes in contralateral non-ischemic hemispheres both during the occlusion and reperfusion periods are thought further evidence of diaschisis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1471-4159.1978.tb10781.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Brain pH in migraine: An in vivo phosphorus-31 magnetic resonance spectroscopy study (1988)
    USA/Oxford, UK : Blackwell Science Ltd
    Cephalalgia 8 (1988), S. 0 
    Details
    ISSN: 1468-2982
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The intracellular pH (pHi ) of cerebral cortex was measured in migraine patients by use of in vivo phosphorus-31 NMR spectroscopy. No changes in pHi were measured during a migraine attack. The long-standing concept that the headache of migraine is due to cerebral vaso-dilatation induced by prodromal vasospasm-induced ischemic acidosis is not substantiated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1468-2982.1988.0804273.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Asymmetric cerebral blood flow patterns in migraine (1987)
    USA/Oxford, UK : Blackwell Science Ltd
    Cephalalgia 7 (1987), S. 0 
    Details
    ISSN: 1468-2982
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Although asymmetric EEG abnormalities have been reported during the headache-free period in migraineurs, asymmetries of regional cerebral blood flow (rCBF) have not been studied. Headache-free rCBF values measured by 133Xe inhalation were lower in migraineurs than in controls. Interhemispheric CBF and regional (anterior versus posterior) CBF did not differ between the groups. When a novel scoring system was used to obtain a mean asymmetry index (MAI), the MAI of the classiccomplicated group was significantly higher than that of the controls but not significantly different from that of the common migraine group. These data suggest that in the headache-free interval rCBF asymmetries, variable in location, exist in classiccomplicated migraineurs. These rCBF changes may be related to the cause or the effect of the focal neurologic dysfunction that occurs during an attack in these patients
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1468-2982.1987.0704245.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Chronic changes in brain Mg2+ concentration after forebrain ischemia in the rat (1991)
    Springer
    Metabolic brain disease 6 (1991), S. 199-206 
    Details
    ISSN: 1573-7365
    Keywords: [Mg2+] ; brain ; forebrain ischemia ; in vivo31P NMR
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Brain Mg2+ ion concentrations, [Mg2+], were evaluated in three groups of animals subjected to either 8 minutes (n=10), or 12 minutes (n=10) of near-complete forebrain ischemia, or sham operation (n=10), from their31P NMR spectra. No significant differences were observed in [Mg2+] among sham operated animals prior to or at any time point after surgery. In the 8-min ischemia group, mean [Mg2+] were significantly lower at 48 (0.28 ± 0.06 mM, p=0.014) and 72 (0.29 ± 0.07 mM, p=0.005) hours post-ischemia when compared to their mean pre-ischemia levels (0.39 ± 0.08 mM). [Mg2+] was restored to preischemia values at 96 hours after induction of ischemia. In the 12 min ischemia group, [Mg2+] were lower at all time points post-ischemia when compared to their pre-ischemia levels. Our data shows that forebrain ischemia causes a chronic decline of cerebral Mg2+ concentration, and the observed reduction of this cation can be partially attributed to concurrent brain tissue alkalosis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00996919
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...