Although Parkinson's disease is a movement disorder, in many patients cognitive dysfunction is an important clinical sign. It is not yet clear whether this is attributable solely to a decrease in dopamine levels, or whether other neurotransmitter systems might be involved as well. In the present study, the importance of the mesocorticolimbic dopamine pathway and a possible convergence with forebrain cholinergic projections to neocortex and hippocampus in the regulation of learning and memory abilities were investigated by using specific lesion paradigms in one or both systems. Lesioning of dopaminergic neurons in the ventral tegmental area resulted in an impaired performance in the reference memory task, whereas the execution of the working memory tasks appeared to be unaffected in the Morris water maze. Analysis of the swim paths revealed that the dopamine-depleted animals were capable of adapting a search strategy on a given testing day but failed to transfer this information to the next day, suggesting a deficit in information storage and/or recall. In contrast, cholinergic lesions alone were without effect in all test paradigms. However, when both dopamine and acetylcholine were depleted, animals were also impaired in the working memory task, indicating that a functional convergence of the inputs from these systems was critical for acquisition of spatial memory. Interestingly, such an additional acquisition deficit appeared only after hippocampal cholinergic depletion regardless of a concurrent disruption of basalocortical cholinergic afferents. Thus, further analyses of cholinergic alterations may prove useful in better understanding the cognitive symptoms in Parkinson's disease.
This bioequivalence study with a trastuzumab biosimilar in healthy male volunteers demonstrated bioequivalence of FTMB with Herceptin(®). FTMB was well tolerated in doses up to 6 mg/kg. Non-linear target elimination was also observed in the pharmacokinetic profile of trastuzumab.
Amyotrophic lateral sclerosis is an incurable disease in which cerebral and spinal motoneurons degenerate, causing paralysis and death within 2-5 years. One of the pathogenic factors of motoneuron death is a chronic excess of glutamate, which exceeds its removal by astrocytes, i.e. excitotoxicity. Extra glutamate uptake in the spinal cord may slow down or prevent motoneuron death. We have engineered cells over-expressing the main glutamate transporter and tested their potential to rescue motoneurons exposed to high levels of glutamate in vitro. The engineered cells protected motoneurons in a motoneuron-astrocyte co-culture at glutamate concentrations when astrocytes were no longer capable of removing glutamate. This suggests that engineered cells, introduced into the spinal column, can help remove glutamate, thereby preventing motoneuron death.
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