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Voss B.,RWTH Aachen | Voss B.,Julich Aachen Research Alliance Translational Brain Medicine JARA BRAIN | Thienel R.,University of Newcastle | Reske M.,Julich Research Center | And 3 more authors.
European Archives of Psychiatry and Clinical Neuroscience

The cholinergic system is essential in mediating cognitive processes. Although there has been extensive research regarding cholinergic receptor subsystems, the specific contribution of the muscarinic and nicotinic receptor system to cognitive processes still has not been sufficiently explored. In the present study, we examined the selective contribution of muscarinic and nicotinic antagonism to cognitive performance in healthy human subjects. A single-blind, double-dummy, time-elapsed, repeated measures cross-over design was used on 15 healthy males. Subjects completed a neuropsychological test battery assessing a wide range of cognitive domains after 0.4 mg scopolamine (intravenous), 0.2 mg/kg mecamylamine (max. 15 mg; oral) or placebo. Subjects were tested under three conditions: placebo/placebo (PP), scopolamine/placebo (SP) and mecamylamine/placebo (MP). Results show that scopolamine significantly impaired the free recall and recognition performance in the verbal learning test. No other cognitive domain was affected, neither by scopolamine nor by mecamylamine. In line with the existing literature, antagonism of muscarinic receptors resulted in specific cognitive impairments, predominantly memory performance. © 2010 Springer-Verlag. Source

Kriebel A.,RWTH Aachen | Kriebel A.,Maastricht University | Rumman M.,RWTH Aachen | Scheld M.,RWTH Aachen | And 8 more authors.
Journal of Biomedical Materials Research - Part B Applied Biomaterials

Peripheral nerve injuries can be surgically repaired by suturing the transected nerve stumps or, in case of larger lesions, by the transplantation of an autologous nerve graft. To avoid donor site morbidity, the development of artificial implants is desired. Clinically, hollow conduits have been used for this purpose but are inferior to the autograft because they lack internal guidance cues for Schwann cells and regenerating axons. In this article, we describe the design of a three-dimensional (3D) scaffold consisting of parallel fibers embedded in a collagen matrix. For this purpose, an electrospinning device was developed to produce and manipulate a 3D array of aligned poly(É-caprolactone) (PCL) microfibers. This fiber array was then incorporated into biodegradable PCL tubes to serve as artificial nerve bridges. Using primary cultures of embryonic chicken dorsal root ganglia, we show that PCL microfibers in the 3D matrix of our composite scaffold guide the direction of Schwann cell migration and axonal growth. Copyright © 2013 Wiley Periodicals, Inc. Source

Bozkurt A.,RWTH Aachen | Bozkurt A.,Goethe University Frankfurt | Boecker A.,RWTH Aachen | Tank J.,RWTH Aachen | And 11 more authors.

An increasing number of biomaterial nerve guides has been developed that await direct comparative testing with the 'gold-standard' autologous nerve graft in functional repair of peripheral nerve defects. In the present study, 20 mm rat sciatic nerve defects were bridged with either a collagen-based micro-structured nerve guide (Perimaix) or an autologous nerve graft. Axons regenerated well into the Perimaix scaffold and, the majority of these axons grew across the 20 mm defect into the distal nerve segment. In fact, both the total axon number and the number of retrogradely traced somatosensory and motor neurons extending their axons across the implant was similar between Perimaix and autologous nerve graft groups. Implantation of Schwann cell-seeded Perimaix scaffolds provided only a beneficial effect on myelination within the scaffold. Functional recovery supported by the implanted, non-seeded Perimaix scaffold was as good as that observed after the autologous nerve graft, despite the presence of thinner myelin sheaths in the Perimaix implanted nerves. These findings support the potential of the Perimaix collagen scaffold as a future off-the-shelf device for clinical applications in selected cases of traumatic peripheral nerve injury. © 2015 Elsevier Ltd. Source

Pauly K.,RWTH Aachen | Pauly K.,Julich Aachen Research Alliance Translational Brain Medicine JARA BRAIN | Seiferth N.Y.,RWTH Aachen | Kellermann T.,RWTH Aachen | And 16 more authors.
Schizophrenia Research

Subtle emotional and cognitive dysfunctions may already be apparent in individuals at risk for psychosis. However, there is a paucity of research on the neural correlates of the interaction of both domains. It remains unclear whether those correlates are already dysfunctional before a transition to psychosis.We used functional magnetic resonance imaging to examine the interaction of working memory and emotion in 12 persons clinically at high risk for psychosis (CHR) and 12 healthy subjects individually matched for age, gender and parental education. Participants performed an n-back task while negative or neutral emotion was induced by olfactory stimulation.Although healthy and psychosis-prone subjects did not differ in their working memory performance or the evaluation of the induced emotion, decreased activations were found in CHR subjects in the superior parietal lobe and the precuneus during working memory and in the insula during emotion induction. Looking at the interaction, CHR subjects, showed decreased activation in the right superior temporal gyrus, which correlated negatively with psychopathological scores. Decreased activation was also found in the thalamus. However, an increase of activation emerged in several cerebellar regions.Dysfunctions in areas associated with controlling whether incoming information is linked to emotional content and in the integration of multimodal information might lead to compensatory activations of cerebellar regions known to be involved in olfactory and working memory processes. Our study underlines that cerebral dysfunctions related to cognitive and emotional processes, as well as their interaction, can emerge in persons with CHR, even in absence of behavioral differences. © 2009 Elsevier B.V. Source

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