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Dive into the research topics where Wulf Pohle is active.

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Featured researches published by Wulf Pohle.


Behavioral and Neural Biology | 1992

Kindling and its consequences on learning in rats

Axel Becker; Gisela Grecksch; Heide-Linde Rüthrich; Wulf Pohle; Bernhard Marx; Hansjürgen Matthies

To study the learning performance of pentylenetetrazol- and amygdala-kindled Wistar rats we used the following learning tests: short-term memory was tested in the response-to-change model, brightness discrimination was tested in a Y-chamber, and two-way active avoidance learning was tested in a shuttle-box. Short-term memory was not impaired by both kindling procedures. Considering two-way active avoidance learning the performance of pentylenetetrazol (PTZ)-kindled rats was significantly diminished. This effect persists over a period of 4 weeks. However, amygdala (AMY)-kindled rats acquired this task like the controls. In brightness discrimination reaction (BDR) the learning performance of PTZ-kindled animals was not influenced. Although the acquisition of BDR was nearly identical, the 24-h retention was remarkably diminished in AMY-kindled rats. It was hypothesized that the different kindling procedures interfere in different ways and extent with neuronal circuits resulting in different functional impairments.


Seizure-european Journal of Epilepsy | 1997

Piracetam prevents pentylenetetrazol kindling-induced neuronal loss and learning deficits

Wulf Pohle; Axel Becker; Gisela Grecksch; A. Juhre; A. Willenberg

The effect of the nootropic drug piracetam (100 mg/kg) on kindled seizures, kindling-induced learning deficits, and histological alterations due to changes in central excitability was investigated in Wistar rats. The animals were kindled by repeated i.p. injections of an initially subconvulsive dose of pentylenetetrazol (PTZ). As a control, piracetam or physiological saline was given 60 minutes before PTZ. Twenty-four hours after completion of kindling the rats were tested in a shuttle-box paradigm. Seven days after the final kindling injection, the animals received a challenge dose of PTZ. Finally, the brains of the rats were processed for histological investigation. Pentylenetetrazol-kindled animals showed increasing seizure scores, and a learning deficit in the shuttle-box. Piracetam had no effect either on kindling development or on the reaction to a challenge dose of PTZ, but it protected the animals against the kindling-induced reduction of learning performance. The substance had no effect on learning performance in control animals. In distinct hippocampal structures, a neuronal cell loss was found in kindled rats. Interestingly, piracetam counteracted this damage efficaciously. The effects of piracetam are discussed in terms of its cytoprotective action. It is suggested that a coadministration of piracetam with clinically used antiepileptic drugs might be useful in antiepileptic therapy.


Brain Research | 1994

Hypoxia protects against the neurotoxicity of kainic acid

Wulf Pohle; Christine Rauca

A normobar hypoxia (9% oxygen) of 8 h reduces the neurotoxicity of a subcutaneous injection of 10 mg/kg kainic acid given one week later. Both seizures and degenerative changes, including cell death of hippocampal and cortical neurons are markedly decreased by hypoxia. It is also shown that hypoxia also markedly reduced the extensive depletion of zinc from mossy fiber terminals normally induced by kainic acid. This suggests that a protective mechanism induced by hypoxia may affect the glutamatergic transmission in these synapses and prevent excessive synaptic excitation. The possible involvement of adenosine and/or GABA in this protective mechanism is discussed.


Peptides | 2004

Trefoil factor family (TFF) expression in the mouse brain and pituitary: changes in the developing cerebellum

Margitta Hinz; Herbert Schwegler; Caroline E. Chwieralski; Gregor Laube; R. Linke; Wulf Pohle; Werner Hoffmann

Trefoil factor family (TFF) peptides, besides their prominent expression in mucous epithelia, are also synthesized in the central nervous system. Previously TFF1 expression was observed in mouse brain astrocytes, while oxytocinergic neurons of the hypothalamo-pituitary axis are recognized sites of TFF3 synthesis. Here, the expression of TFF1, TFF2, and TFF3 was systematically studied using reverse transcription-polymerase chain reaction (RT-PCR) analysis of dissected adult mouse brain regions including the pituitary. Additionally, the developmental profile of TFF expression in murine cerebral cortex and cerebellum was monitored. Overall, the expression patterns of the three TFF genes differed. The TFF1 and TFF2 profiles shared some similarities, whereas the TFF3 expression pattern was completely different. TFF1 was nearly uniformly, but weakly expressed in all brain regions tested. The TFF1 and TFF2 expression patterns differed characteristically in the pituitary where abundant TFF2 transcription was detected in the anterior and not the posterior lobe and the expression level in males was higher than in females. In contrast, TFF3 expression was limited to the hippocampus, the temporal cortex, and the cerebellum, the latter being surprisingly the major site of expression. Here, TFF3 mRNA appeared to be restricted mainly to neurons and not glial cells. Cerebellar TFF3 expression is clearly developmentally regulated (maximum at P15), indicating a role for TFF3 during postnatal cerebellar development.


Brain Research | 1976

Increased fucose incorporation into rat hippocampus during learning. A biochemical and microautoradiographic study

N. Popov; Heide-Linde Rüthrich; Wulf Pohle; S. Schulzeck; Hansjürgen Matthies

The incorporation of intraventricularly infected L-[1-3H]fucose into proteins of the hippocampus and visual cortex was studied during the acquisition of a shock-motivated brightness discrimination in rats. The labeling of Tris-soluble proteins from both regions was not significantly changed during learning, whereas solubilized insoluble proteins obtained from the hippocampus revealed an increased fucose incorporation in learned animals. A significant enhanced incorporation into some distinct, slow-moving, carbohydrate-rich protein bands, separated by polyacrylamide gel electrophoresis, was observed in material from CA1 and CA3 sectors as well as from area dentata of the hippocampus formation during acquisition. The corresponding gel bands from the visual cortex exhibited no differences between trained animals and controls. Jointly performed microautoradiography showed an increased fucose incorporation into most areas of the hippocampus in learned animals compared with active and passive controls. The most significant differences were found to occur mainly in substructures consisting of densely packed neuronal cells.


Brain Research | 1987

Incorporation of [3H]fucose in rat hippocampal structures after conditioning by perforanth path stimulation and after LTP-producing tetanization

Wulf Pohle; Lisette Acosta; Heinz Ru¨thrich; Manfred Krug; Hansju¨rgen Matthies

The contribution of glycoprotein synthesis to functional synaptic changes and to the formation of memory traces was investigated by autoradiographic determination of the incorporation of [3H]fucose into the hippocampal structures of rats. In the first experiment, the fucose incorporation was measured after induction of post-tetanic long-term potentiation (LTP) in granular cell synapses by repeated tetanization (200 cps) of the perforant path, and after stimulation of this hippocampal input by the same number of impulses with very low frequency (0.2 cps) not producing LTP. In the second experiment, the incorporation of fucose was determined after an active avoidance training using the stimulation of the perforant path by impulse trains of 15 cps as conditioning stimuli, and after a session of corresponding unpaired stimulations of the perforant path. Unstimulated animals were used in both experiments to measure the basal glycosylation. LTP-producing tetanization resulted only in a slight increase of incorporation into the ipsilateral hippocampal structures without significant differences to similar changes after the corresponding control stimulation with single impulses. After a session of unpaired stimulation of the perforant path with impulse trains of 15 cps only slight and inconsistent changes of incorporation occurred in the hippocampus too. However, after conditioning by the corresponding perforant path stimulation as conditioned stimulus, considerable increases of incorporation were observed in all structures of the ipsilateral hippocampus, when compared to the unpaired control stimulation. An enhanced labeling occurred also in some structures of the contralateral hippocampus mainly receiving commissural inputs. The results suggest again, that the activation of one single hippocampal afferent, even if producing LTP, would not be sufficient to induce an increased glycosylation of neuronal proteins. The increase of glycoprotein formation seems to require the convergence of several inputs, which can be assumed to occur during learning. Therefore, LTP of a single synaptic population seems not to represent the complete long-lasting memory trace, but only one of its components, or a preceding transient storage mechanism.


Brain Research | 1976

Time course and disposition of fucose radioactivity in rat hippocampus. A biochemical and microautoradiographic study.

N. Popov; Wulf Pohle; Heide-Linde Rüthrich; S. Schulzeck; Hansjürgen Matthies

Male adult rats were injected intraventricularly with L-[1-3H]fucose. At various intervals, ranging between 30 min and 11 days, one-half of the brain was prepared for microautoradiography, and the hippocampus from the other side was prepared for biochemical investigations. The TCA-precipitable proteins from the hippocampus homogenate were maximally labeled at between 8 and 24 h and remained at a high radioactivity level even 11 days after [3H]-fucose injection, the labeling being predominantly present in the solubilized insoluble proteins. Using gel electrophoretic separation, study of Tris-soluble material indicated a rapid turnover of soluble fucose-containing glycoproteins, whereas several slow-migrating bands of solubulized proteins revealed a time course suggesting the presence of fucose-containing glycoproteins with slower turnover rates. Using microautoradiography, a rapid labeling of neuronal cell bodies of the hippocampus was found, whereas the nuclei were not labeled. Perikarya were maximally labeled 4 h after [3H]fucose application. The radioactive material was continuously transported from the soma into the corresponding fiber layers, the latter being maximally labeled at a pulse interval of one day; even 10 days later a considerable amount of radioactivity could be detected in the neuropil.


European Journal of Neuroscience | 2000

Repeated long‐term potentiation induces mossy fibre sprouting and changes the sensibility of hippocampal granule cells to subconvulsive doses of pentylenetetrazol

Hadir Hassan; Wulf Pohle; Heinz Rüthrich; Rudolf Brödemann; Manfred Krug

Electrical and chemical kindling induces sprouting of the mossy fibre system and potentiation of evoked field potentials in the dentate gyrus. It has been postulated that such changes may also be induced by repeated induction of long‐term potentiation (LTP) with tetanic stimulation of the perforant pathway. LTP was induced in rats chronically implanted with stimulation electrodes in the ipsilateral and contralateral angular bundles and with a recording electrode in the ipsilateral dorsal dentate gyrus. The animals were stimulated 10 times on 10 consecutive days but with different tetanization strengths. Sprouting of the mossy fibres terminating in the CA3 region was significantly induced only in the group of ‘strongly’ tetanized animals, but not in that of ‘weakly’ tetanized animals, or in low‐frequency stimulated animals. Additionally, a novel form of potentiation which was previously found in pentylenetetrazol (PTZ)‐kindled animals was also observed in the group of ‘strongly’ and ‘weakly’ tetanized rats. Differences in duration of this potentiation were found between the two groups of animals tetanized with different strengths. The results further demonstrate that morphological and functional changes in the hippocampus, similar to those seen after kindling, can also occur in an activation paradigm leading to long‐lasting synaptic plasticity but not accompanied by seizure activity.


Pharmacology, Biochemistry and Behavior | 2000

Hypothermia Inhibits Pentylenetetrazol Kindling and Prevents Kindling-Induced Deficit in Shuttle-Box Avoidance

Christine Rauca; Wulf Pohle; Katrin Grunenberg; Sören Franze

In this study, we evaluated the effects of hypothermic exposure on pentylenetetrazol (PTZ) kindling and the resulting deficit of shuttle-box avoidance learning in rats. Additionally, to acknowledge neuronal cell loss, we estimated the number of toluidine blue-positive cells in different brain regions after PTZ kindling and hypothermia exposure in comparison to different normothermic and hypothermic controls. To obtain hypothermic conditions over a period of up to about 3 h, 30 min after PTZ application the animals were treated with 5 mg/kg chlorpromazine (CP) and 25 min later exposed to 15 degrees C cold water for 5 min. Under these conditions the rectal and the striatal temperature were reduced up to a maximum of 5 degrees C. The additional injection of CP did not influence the development of PTZ kindling. Animals treated with PTZ/CP and exposed to hypothermia did not reach the criterion for kindling. Furthermore, this group of animals did not demonstrate any learning deficit. Forty-eight hours after the last kindling application the number of toluidine blue-stained cells was decreased in the investigated brain regions (hippocampal CA1 and CA3 sector, hilus, and cingular cortex) of kindled rats. Hypothermia protected from cell damage in the hippocampal CA3 sector and in the hilus. Results suggest that the inhibiting effect of hypothermia on the development of kindling and the following learning deficit possibly resulted from the suppression of cell damage in distinct brain structures on PTZ-kindled rats.


Naunyn-schmiedebergs Archives of Pharmacology | 1996

Neuropeptide Y and somatostatin immunoreactivity in the rat hippocampus after moderate hypoxia

Christoph Schwarzer; Günther Sperk; Christine Rauca; Wulf Pohle

Transient moderate hypoxia has been previously shown to exert a potent protective role to subsequently applied convulsant drugs. We now investigated neuropeptide Y and somatostatin immunoreactivities seven days after moderate hypoxia (9% O2 in N2 for two times 8 h) in the hippocampus of the rat. A slight reduction of somatostatin immunoreactive cells was observed in the hilus of the dorsal and ventral hippocampus. At the same time, the total number of neuropeptide Y immunoreactive neurons was increased in this area due to a pronounced increase in staining of presumable basket cells. There was also increased staining of neuropeptide Y positive fibers in the outer molecular layer. Our data suggest activation of neuropeptide Y containing interneurons after a moderate or a mild transient hypoxia. Activation of these inhibitory neurons may contribute to the protective effect of this treatment.

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Christine Rauca

Otto-von-Guericke University Magdeburg

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Heide-Linde Rüthrich

Otto-von-Guericke University Magdeburg

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Axel Becker

Otto-von-Guericke University Magdeburg

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Gisela Grecksch

Otto-von-Guericke University Magdeburg

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Heinz Rüthrich

Otto-von-Guericke University Magdeburg

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Manfred Krug

Otto-von-Guericke University Magdeburg

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A. Juhre

Otto-von-Guericke University Magdeburg

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A. Willenberg

Otto-von-Guericke University Magdeburg

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Caroline E. Chwieralski

Otto-von-Guericke University Magdeburg

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