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A Wagner

Publications and source records attributed to A Wagner.

At least 415 records · Page 23Linked to original sources
PubMed1984

Identification of projecting neurons in rat neostriatal slices.

Spiny neurons projecting to substantia nigra (SN) were identified by combining retrograde transport of tracers in vivo with intracellular staining in vitro. First, neostriatal projection neurons were retrogradely labeled by the injection of fluorescent tracers into the ipsilateral SN. Then, slices were taken from the neostriata containing the retrogradely labeled cells. Cells were impaled for intracellular recording and stained by intracellular dye injection. All cells were of the spiny type and 75% contained both dyes, the intracellularly injected dye as well as the retrogradely transported tracer. Thus, most intracellular recordings in neostriatal slices are obtained from spiny neurons projecting to SN.

Animals↗
PubMed1984

Clinical value of immunohistochemistry with AF-antibody in the diagnosis of familial amyloid neuropathy.

Peripheral polyneuropathy associated with recurrent diarrhoea and orthostatic hypotension was observed in two unrelated German kinships and two sporadic cases. Congo red staining and polarization microscopy of biopsy specimens revealed amyloid deposits. Immunohistochemical investigation using the indirect immunoperoxidase staining with antisera to several purified amyloid fibril proteins showed a positive reaction with an antiserum to the prealbumin-related AF-amyloid in the families and one of the sporadic cases and with an antiserum to the immunoglobulin light chain amyloid (A lambda) in the other sporadic case. Therefore, the amyloid of the families and one of the sporadic cases was identified as the prealbumin-related AF amyloid, while the amyloid of the other sporadic case was of immunoglobulin origin. It is concluded that immunohistochemistry with antisera to the different amyloid proteins is useful in the differential diagnosis of amyloid neuropathy.

Adult↗
PubMed1984

Effects of frontal motor cortex ablation on the ultrastructure of cat substantia nigra.

3,4 and 5 days after the removal by suction of the left motor and premotor cortex in cats, the presence of ultrastructural changes in the substantia nigra was investigated. Whereas after 3 days dark bouton degeneration was rare, after 4- and 5-day survival it was regularly found for a distinct type of synapse containing in its bouton densely packed small round vesicles and possessing an asymmetric synaptic junction with a dendrite. Often these darkly degenerated boutons contained dense bodies which were also observed in the same type of synapse not yet exhibiting a dark axoplasm. Various inclusions, especially glycogen depots, were present in these boutons suggesting that they were in the process of degeneration. The glial reaction was comparatively severe. In addition, darkly shrunken dendrites contacted both, by intact and by altered boutons were frequently encountered as well as single degenerated neuronal perikarya. The nature of this effect, i.e. whether transneuronal or retrograde, could not be clarified. All these alterations were found bilaterally after the unilateral cortex ablation, and were confined to the substantia nigra pars compacta along its whole anterior-posterior extent. In the pars reticulata, solely traversing myelinated axons in the process of degeneration were observed. Thus, the results are in agreement with the older studies and with evidence from primates demonstrating that the substantia nigra receives a bilateral projection from the motor and premotor cortex.

Animals↗
PubMed1984

Types of synapses and degeneration in the thalamic nucleus ventralis oralis posterior after cerebellar lesions in the squirrel monkey.

The thalamic nucleus ventralis oralis posterior (V.o.p) of Saimiri sciureus corresponds to the posterior basal part of the ventral lateral nucleus and is characterized by medium-sized nerve cells. Electron microscopic study revealed seven different types of synapses and the size of vesicles in each has been quantitatively determined. The synapse of type I LR (Large with Rounded vesicles) is considerably larger than the similar type IV MR (Medium-sized with Rounded vesicles) both contain round to ovoid vesicles and a large amount of mitochondria. Their contacts are asymmetric with presynaptic aggregations of synaptic vesicles. The type I LR synapses may also form button-like contacts (adhering junctions) without presynaptic accumulation of synaptic vesicles. The type II F (large with Flattened vesicles) symmetric synapses are formed by large boutons containing flattened vesicles and are partially encircled by astrocytic processes. The type III SR (Small with Rounded vesicles) bouton possesses small, nearly round till ovoid dense vesicles and forms a strongly asymmetric contact. In the type V SO (Small with Ovoid vesicles) bouton, the pleomorphic vesicles are larger than in type III and form asymmetric contacts with relatively small dendrites. Finally, two types of dendritic terminals were distinguished (VI and VII), which can be differentiated chiefly by the distribution of synaptic vesicles; VI DE (Dendritic terminal with Evenly distributed vesicles) and VII DC (Dendritic terminal with Clustered vesicles). Following hemicerebellectomy (4 experiments), only the type I LR and type IV MR synapses were found to be degenerated in the thalamic nucleus V.o.p. Similar degeneration was found in the ventral intermediate nucleus (V.im) which corresponds to the most rostral part of the VPL nucleus (VPLo). After three days survival, the forms of degeneration were largely neurofilamentous or pale, becoming mostly dark after four days. Degeneration of these same types of synapses appeared also in the nucleus ventralis oralis internus (V.o.i) and in the nucleus dorsalis intermedius (D.im), which lies above the ventral intermediate and ventrocaudal nuclei of the thalamus. These results are in good agreement with the findings in the light microscopic investigations if one considers the cyto- and myeloarchitectonic boundaries between the V.o.p and V.im.

Animals↗
PubMed1984

[Oculo-auricular phenomenon and its value in neurologic diagnosis].

The oculoauricular phenomenon is a synergism between an external eye muscle, the m. rectus lateralis, and the facialis innervated m. retroauricularis. In the neurological diagnostic this phenomenon permits a differentiation between the abducens nerve paresis of peripheral and of nuclear origine. In addition to this electromyographic examination from the m. retroauricularis can discover disturbances of the neuromuscular transmission and facilitate an early prognostic estimation of peripheral facialis paresis.

Abducens Nerve↗
PubMed1984

[Acoustically evoked brain stem potential in Wilson disease].

By 48 patients with Wilson's disease the brainstem acoustic evoked potentials were stated. There were 35 pathological findings (73%), 13 were normal (27%). The waves, determined by the middle and upper brainstem (Pons and Mesencephalon) showed most of all pathological changes. Those patients with forms of Wilson's disease called Pseudoskelerose and Pseudoparkinson showed the most pathological findings. But one could watch these findings by about 30% of patients in preclinical stage. This method can possibly be used for early detection of disorders of brainstem functions and in the same way it can be used for control of treatment by patients in preclinical stage.

Adult↗
PubMed1984

[The quantification of drug information].

The necessary intensification of the information activity in the pharmacy service raises the question of the demand of each drug on the pharmacist as regards its information volume. The wealth of information on the application of drugs necessitates their differentiation and systematization. One differentiates between basic and additional information. On determining the frequency of occurrence of 21 pieces of additional information concerning 1321 pharmaceutical preparations, the mean information content according to Shannon [17] is calculated. The quantified results determine drug information as a statistical quantity from which their semantics for the receiver (user of the drug) must be abstracted. To consider the aspects concerning the contents and function of additional information, the weighting coefficients of 85 drug groups were calculated (by means of the triangular matrix method), and introduced. It is suggested to combine the numerical values of the statistically defined amounts of information with the quantities deduced from the meaningfulness in a parameter of the informational potential (IP) of pharmaceutical preparations. Finally, the authors convey their ideas of the benefit from, and the possible uses of, the IP.

Drug Information Services↗
PubMed1984

[Value of mechanographic studies in neuromuscular function diagnosis].

Mechanographic examinations have hitherto played only a minor role in general clinical neuromuscular functional diagnostics. The purpose of this contribution is, therefore, to present an appropriate recording apparatus (W. Zett , 1969), to report on the values that can be considered normal and to outline the diagnostic value of the method using clinical applications as examples. Special value is attached to simultaneous recording of the EMG and the mechanograph because this method permits differentiated conclusions to be drawn regarding disturbances in muscular activity, the electromechanical coupling and the actual process of contraction. The method is also important for pharmacological investigations and should be used principally in connection with musclepathology for objectifying the effects of medication.

Adolescent↗
PubMed1983

Retrograde labeling of striato-nigral neurons in the rat by three different tracers.

The three tracers horseradish peroxidase (HRP), 4',6-diamidino-2-phenylindol-2HCl (DAPI) and Fast Blue (FB) differ in retrograde labeling of striato-nigral neurons. After a 24 h survival, injection of DAPI into the ventral tegmentum labeled numerous cells throughout the neostriatum, whereas an identical amount of HRP only labeled cells in circumscribed areas of the neostriatum. Injections of FB labeled a substantial number of neostriatal neurons after a survival time of 4 days, but not after 24 h. In addition, differences between retrograde staining of striato-nigral neurons and layer V pyramidal cells of the ipsilateral neocortex, also labeled in these experiments, were found.

Amidines↗
PubMed1983

Electrophysiologic studies on the pallido- and cerebellothalamic projections in squirrel monkeys (Saimiri sciureus).

Thalamic projections of the pallidum and the deep cerebellar nuclei were studied by unitary recordings as well as field potential analysis in the thalamus of squirrel monkeys (Saimiri Sciureus) under sodium pentobarbital anesthesia. Stimulation of the pallidum produced a positive field potential preceded by incoming afferent fiber volleys in the thalamus. Spontaneous discharges of thalamic neurons were suppressed during this positive potential corresponded to that of the hyperpolarizing potential. The hyperpolarization was presumed to be a monosynaptic inhibitory post synaptic potential by the short synaptic delay (about 0.5--0.7 ms) and responsiveness to high frequency stimulation (over 150 Hz). The positive field potential on stimulation of the external pallidal segment was distributed in L.po (VA) and the reticular thalamic nucleus around L.po, whereas that on stimulation of the internal segment was in V.o.a (the anterior basal part of VL) and in Z.o (upper part of VL). The projection of the external segment appeared to be less dense than that of the internal segment. The projection of deep cerebellar nuclei was situated in V.o.a, V.o.p (posterior part of basal part of VL), V.o.i (VLm), the intralaminar nucleus (CL), and some part of V. im (the rostral part of VPLo). Projections of the interpositus and dentate nuclei were distributed in a more anterior part than those of the fastigial nucleus. A certain topographical arrangement of the projections of these three nuclei was found in V.o.p, V.o.i and V.im. No significant overlap was detected between pallidum and the deep cerebellar nuclei within the thalamus.

Animals↗
PubMed1983

Neuronal and synaptic arrangements of the lateral geniculate nucleus in night-active primates.

The lateral geniculate nucleus (LGN) of Aotus trivirgatus and Nycticebus coucang shows two types of neurons at the ultrastructural level: a large thalamo-cortical relay neuron (TCR) and a small neuron of Golgi type II, which is considered to be an interneuron. The interneuron contains small aggregations of synaptic vesicles in the perikaryon adjacent to the cell membrane in synaptic contact to a TCR neuron. Only in the perikaryon of the interneurons can cilia have their origin. After unilateral enucleation, neurofilamentous or dark degenerations of large boutons with round vesicles (type RL) occur in the outer layers of the contralateral LGN and in the inner layers of the ipsilateral LGN. The optic terminals establish synaptic contacts in the glomerulus with dendritic spines of the TCR neurons and with presynaptic dendrites (F2) of interneurons.

Animals↗
PubMed1983

Studies on the cerebellocerebral and thalamocortical projections in squirrel monkeys (Saimiri sciureus).

Laminar field potential analysis of the cerebellocerebral and thalamocortical (T-C) responses was carried out in the cerebral cortex of squirrel monkeys (Saimiri sciureus) under pentobarbital anesthesia. Anatomical studies using horseradish peroxidase (HRP) were combined with electrophysiological studies. Stimulation of the fastigial nucleus induced bilaterally surface positive-depth negative potentials, i.e., deep T-C responses, in the medial part of the motor cortex and in the parietal cortex (mainly area 5) with a latency of 4 to 5 ms. Stimulation of the interpositus and dentate nucleus evoked contralaterally surface negative-depth positive potentials (superficial T-C responses) in the intermediate and lateral part of the motor cortex and in the premotor cortex (area 6) with a latency of 3 to 4 ms. Stimulation of the thalamic nuclei as well as the HRP study revealed that the medial part of V.o.p. (posterior basal part of VL) and Z.o (upper part of VL) and the intralaminar nucleus (CL) mediate the interpositus- and dentate-induced responses to the motor and premotor cortex, and that the ventrolateral part of V.o.p. and Z.im (upper part of VPLo) relays the fastigial-induced responses to the motor cortex.

Animals↗
PubMed1983

Effects of desglycinamide-arginine-vasopressin (DG-AVP) on memory processes in diabetes insipidus patients and non-diabetic subjects.

The effects of desglycinamide9-arginine8-vasopressin (DG-AVP) on memory processes have been studied in patients with central diabetes insipidus (DI) and in non-diabetic control patients. Acute im injection of DG-AVP improved some aspects of short-term memory. Subchronic intranasal administration of DG-AVP facilitated short-term memory more consistently and in addition improved long-term memory. DG-AVP increased the attention, but only in the non-diabetic subjects. The effects of DG-AVP on memory processes persisted after discontinuation of treatment. DG-AVP did not affect the parameters for water and electrolyte metabolism, blood pressure and pulse rate neither in DI nor in the control patients. Thus, the memory effects of DG-AVP are probably mediated by a direct action on the central nervous system.

Adolescent↗
PubMed1983

[Modification of 2,4-dichlorophenoxyacetate-induced myotonia of cold blood muscles by variations in external Ca++ and K+ concentrations].

The influence of several Ca++- and K+-concentrations on the mechanograms, electromyograms, membrane potentials and ion contents of myotonic cold blood muscle was investigated. In accordance with the wellknown effects of the warm blood muscle the results show that the application of Ca++ and the withdrawal of K+ improve the myotonic phenomena while the withdrawal of Ca++ and the application of K+ reinforce the myotonic reaction. The results show that 2,4-D blocks the Ca++-influx as well the transport of Na+ and K+ through the membrane. As a consequence of these results it is supposed that 2,4-D changes the charges of the muscle fiber membrane and in this way induces the myotonic phenomena. In the paper the results of the authors' investigations are being discussed in connection with the chloride-hypothesis.

2,4-Dichlorophenoxyacetic Acid↗