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
    Brain Insults in Rats Induce Increased Expression of the BDNF Gene through Differential Use of Multiple Promoters (1994)
    Oxford, UK : Blackwell Publishing Ltd
    European journal of neuroscience 6 (1994), S. 0 
    Details
    ISSN: 1460-9568
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The rat brain-derived neurotrophic factor (BDNF) gene consists of four short 5-exons linked to separate promoters and one 3′-exon encoding the mature BDNF protein. Using in situ hybridization we demonstrate here that kindling-induced seizures, cerebral ischaemia and insulin-induced hypoglycaemic coma increase BDNF mRNA levels through insult- and region-specific usage of three promoters within the BDNF gene. Both brief (2 min) and longer (10 min) periods of forebrain ischaemia induced significant and major increases only of exon III mRNA in the dentate gyrus. Following hypoglycaemic coma (1 and 30 min), exon III mRNA was markedly elevated in the dentate gyrus and, in addition, exon I mRNA showed a moderate increase. Single and recurrent (n= 40) hippocampal seizures significantly increased expression of exon I, II and III mRNAs in the dentate gyrus granule cells. After recurrent seizures, including generalized convulsions, there were also major increases of both exon I and III mRNAs in the CA3 region, amygdala, piriform cortex and neocortex, whereas in the hippocampal CA1 sector marked elevations were detected only for exon III mRNA. The insults had no effect on the level of exon IV mRNA in the brain. The region- and insult-specific pattern of promoter activation might be of importance for the effectiveness of protective responses as well as for the regulation of plastic changes following brain insults.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1460-9568.1994.tb00303.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
    Regional Forebrain Noradrenalin Release in Response to Focal and Generalized Seizures Induced by Hippocampal Kindling Stimulation (1992)
    Oxford, UK : Blackwell Publishing Ltd
    European journal of neuroscience 4 (1992), S. 0 
    Details
    ISSN: 1460-9568
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: In vivo microdialysis was used to monitor noradrenalin (NA) release in the rat hippocampus, sensorimotor cortex and amygdala in response to seizures induced by electrical kindling stimulation in the hippocampus. Generalized seizures increased NA output in the hippocampus five-fold above baseline level (as assessed with 2-min sampling periods). The peak value was seen 2–4 min after onset of seizure activity and baseline was reached after another 6–8 min. In the sensorimotor cortex, there was a seven-fold increase showing a similar time-course. Focal hippocampal seizures gave rise to three-fold and 80% increases above baseline in the hippocampus and sensorimotor cortex, respectively. A unilateral knife transection of the dorsal noradrenergic bundle reduced hippocampal NA release induced by focal seizures by 53%. In animals subjected to 30 stimulus-evoked seizures with 5-min intervals (‘rapid kindling’), maximal NA output was observed after the third seizure in both hippocampus (237% increase) and amygdala (122% increase). NA levels tapered off with repeated stimulation and reached baseline after nine stimulations in the hippocampus; in the amygdala, the NA output was still slightly elevated at the end of the stimulation period. These results indicate that there is a general activation of the locus coeruleus system during focal as well as generalized seizures, as evidenced by marked increases in transmitter release from noradrenergic terminals in all forebrain areas studied. NA output in areas exhibiting seizure activity is dependent on impulse flow in locus coeruleus neurons and probably also on local regulatory mechanisms active at the noradrenergic terminal level. The increase in inhibitory noradrenergic transmission in both epileptic and non-epileptic brain regions may dampen ongoing seizure activity as well as lessen its spread and generalization.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1460-9568.1992.tb00875.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
    Afferent-specific modulation of short-term synaptic plasticity by neurotrophins in dentate gyrus (2000)
    Oxford, UK : Blackwell Science Ltd
    European journal of neuroscience 12 (2000), S. 0 
    Details
    ISSN: 1460-9568
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Neurotrophins modulate synaptic transmission and plasticity in the adult brain. We here show a novel feature of this synaptic modulation, i.e. that two populations of excitatory synaptic connections to granule cells in the dentate gyrus, lateral perforant path (LPP) and medial perforant path (MPP), are differentially influenced by the neurotrophins BDNF and NT-3. Using field recordings and whole-cell patch-clamp recordings in hippocampal slices, we found that paired-pulse (PP) depression at MPP–granule cell synapses was impaired in BDNF knock-out (+/–) mice, but PP facilitation at LPP synapses to the same cells was not impaired. In accordance, scavenging of endogenous BDNF with TrkB–IgG fusion protein also impaired PP depression at MPP–granule cell synapses, but not PP facilitation at LPP–granule cell synapses. Conversely, in NT-3+/– mice, PP facilitation was impaired at LPP–granule cell synapses whilst PP depression at MPP–granule cell synapses was unaffected. These deficits could be reversed by application of exogenous neurotrophins in an afferent-specific manner. Our data suggest that BDNF and NT-3 differentially regulate the synaptic impact of different afferent inputs onto single target neurons in the CNS.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1460-9568.2000.00956.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
    Functional properties and synaptic integration of genetically labelled dopaminergic neurons in intrastriatal grafts (2005)
    Oxford, UK : Blackwell Science Ltd
    European journal of neuroscience 21 (2005), S. 0 
    Details
    ISSN: 1460-9568
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Intrastriatal grafts of fetal ventral mesencephalic tissue, rich in dopaminergic neurons, can reverse symptoms in Parkinson's disease. For development of effective cell replacement therapy, other sources of dopaminergic neurons, e.g. derived from stem cells, are needed. However, the electrophysiological properties grafted cells need to have in order to induce substantial functional recovery are poorly defined. It has not been possible to prospectively identify and record from dopaminergic neurons in fetal transplants. Here we used transgenic mice expressing green fluorescent protein under control of the rat tyrosine hydroxylase promoter for whole-cell patch-clamp recordings of endogenous and grafted dopaminergic neurons. We transplanted ventral mesencephalic tissue from E12.5 transgenic mice into striatum of neonatal rats with or without lesions of the nigrostriatal dopamine system. The transplanted cells exhibited intrinsic electrophysiological properties typical of substantia nigra dopaminergic neurons, i.e. broad action potentials, inward rectifying currents with characteristic ‘sag’, and spontaneous action potentials. The grafted dopaminergic neurons also received functional excitatory and inhibitory synaptic inputs from the host brain, as shown by the presence of both spontaneous and stimulation-evoked excitatory and inhibitory postsynaptic currents. Occurrence of spontaneous excitatory and inhibitory currents was lower, and of spontaneous action potentials was higher, in neurons placed in the dopamine-depleted striatum than of those in the intact striatum. Our findings define specific electrophysiological characteristics of transplanted fetal dopaminergic neurons, and we provide the first direct evidence of functional synaptic integration of these neurons into host neural circuitries.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1460-9568.2005.04116.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
    Seizure suppression in kindling epilepsy by intracerebral implants of GABA- but not by noradrenaline-releasing polymer matrices (1994)
    Springer
    Experimental brain research 79 (1994), S. 385-394 
    Details
    ISSN: 1432-1106
    Keywords: Epilepsy ; GABA ; Noradrenaline Graft ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Gamma-aminobutyric acid (GABA)-releasing polymer matrices were implanted bilaterally, immediately dorsal to the substantia nigra, in rats previously kindled in the amygdala. Two days after implantation, rats with GABA-releasing matrices exhibited only focal limbic seizures in response to electrical stimulation, whereas animals with control matrices devoid of GABA had generalized convulsions. GABA release from the polymer matrices was high during the first days after implantation, as demonstrated both in vitro and, using microdialysis, in vivo. The anticonvulsant effect was no longer observed at 7 and 14 days at which time GABA release was found to be low. In a parallel experiment, polymer matrices containing noradrenaline (NA) were implanted bilaterally into the hippocampus of rats with extensive forebrain NA depletion induced by an intra-ventricular 6-hydroxydopamine injection. No effect on the development of hippocampal kindling was observed, despite extracellular NA levels exceeding those of rats with intrahippocampal locus coeruleus grafts that have previously been shown to retard kindling rate. The results indicate that GABA-releasing implants located in the substantia nigra region can suppress seizure generalization in epilepsy, even in the absence of synapse formation and integration with the host brain. In contrast, the failure of NA-releasing polymer matrices to retard the development of seizures in NA-depleted rats suggests that such an effect can only be exerted by grafts acting through a well-regulated, synaptic release of NA.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00229179
    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...