Jörg A. Nagel

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The effects of injections of the neuropeptide substance P or the GABA agonist muscimol on performance of a step-down inhibitory avoidance task were examined. Immediately after the training trial, rats with chronically implanted cannulas were injected with 100 or 10 ng of substance P or 500 or 50 ng of muscimol into the region of the nucleus basalis(More)
Performance on visual tracking tasks was measured in groups of Alzheimer-type dementia, pseudodementia of depression, and elderly normal controls. Smooth pursuit tracking errors were identified by counting the number of catch-up saccades required to compensate for failure of the smooth pursuit system. The group with Alzheimer-type dementia had significantly(More)
The effect of age and gender on eye tracking performance was studied in normal healthy subjects. Two measures of tracking performance, phase corrected cross-correlation coefficients and number of catch-up saccades were determined. The cross-correlation measures revealed a differential effect with the elderly men demonstrating significantly better tracking(More)
High mortality rate in rats with large medial preoptic lesions discourage their use in studies of brain function. However, virtually all such animals (six out of seven) survived indefinitely if kept at an ambient temperature of 15 degrees C for 2 hours before and 10 to 12 hours after the lesions were made. Although these rats appeared otherwise healthy,(More)
Concentrations of dopamine, serotonin, and some of their metabolites were analyzed by means of high-performance liquid chromatography in brain samples obtained from rats operantly conditioned to use one paw for water-reinforced lever pressing. In the first experiment, the side of paw usage was determined by physical constraint (forced-handedness condition),(More)
The Artificial Accommodation System is a mechatronic lens implant that will restore the ability of the human eye to accommodate. Therefore, the accommodation demand has to be acquired. One possibility is to measure the vergence angle of the eyeballs in reference to an external field. Using the earth magnetic field as reference the proof of this measuring(More)
The effect of peripheral injections of substance P (SP) on performance in two different configurations of an automated tunnel maze was examined in three experiments. In two experiments, the effect of pretrial SP injections (10-1000 micrograms/kg) on performance in the hexagonal and radial maze configuration of an automated tunnel maze was investigated. In(More)
The Artificial Accommodation System is a micro mechatronic system which will be implanted into the capsular bag to replace the human crystalline lens. Depending on the patients' actual need for accommodation, the system autonomously adapts the refractive power of its integrated optical element in a way that the projection on the patients' retina results in(More)
Extensive septal lesions produced a persistent (76 days) reduction in rearing behavior which was not directly attributable to altered deprivation states, emotionality, activity levels, or competing behaviors and which occurred in familiar as well as various novel testing environments. Changes in visual, olfactory, or conspecific stimuli ameliorated or had(More)