Neuropsychopharmacology
October 2024
Cognitive flexibility and working memory are important executive functions mediated by the prefrontal cortex and can be impaired by circadian rhythm disturbances such as chronic jet lag (CJL) or shift work. In the present study, we used mice to investigate whether (1) simulated CJL impairs cognitive flexibility, (2) the orexin system is involved in such impairment, and (3) nasal administration of orexin A is able to reverse CJL-induced deficits in cognitive flexibility and working memory. Mice were exposed to either standard light-dark conditions or simulated CJL consisting of series of advance time shifts.
View Article and Find Full Text PDFThe brown rat () is one of the major animals both in the laboratory and in urban centers. Brown rats communicate various types of information using pheromones, the chemicals that mediate intra-species communication in minute amounts. Therefore, analyses of pheromones would further our understanding of the mode of life of rats.
View Article and Find Full Text PDFCognitive flexibility refers to the ability to modify learned behavior in response to changes in the environment. In laboratory rodents, cognitive flexibility can be assessed in reversal learning, i.e.
View Article and Find Full Text PDFBackground: Sedative-hypnotic (SH) medications are often used to treat chronic insomnia, with potentially serious long-term side effects. The objective of this study is to evaluate an interprofessional SH deprescribing program within a community team-based, primary care practice, with or without cognitive behavioural therapy for insomnia (CBT-I).
Methods: Retrospective chart review for patients referred to the team pharmacist for SH deprescribing from February 2016 to June 2019.
Relief learning is the association of environmental cues with the cessation of aversive events. While there is increasing knowledge about the neural circuitry mediating relief learning, the respective molecular pathways are not known. Therefore, the aim of the present study was to examine different putative molecular pathways underlying relief learning.
View Article and Find Full Text PDFNeuropeptide S (NPS) is a neuropeptide involved in the regulation of fear. Because safety learning is impaired in patients suffering from anxiety-related psychiatric disorders, and polymorphisms of the human neuropeptide S receptor (NPSR) gene have also been associated with anxiety disorders, we wanted to investigate whether NPSR-deficiency interferes with safety learning, and how prior stress would affect this type of learning. We first investigated the effect of pre-exposure to two different types of stressors (electric stimuli or immobilization) on safety learning in female and male C57Bl/6 mice, and found that while stress induced by electric stimuli enhanced safety learning in males, there were no differences in safety learning following immobilization stress.
View Article and Find Full Text PDFProteolysis as mediated by one of the major cellular protein degradation pathways, the ubiquitin-proteasome system (UPS), plays an essential role in learning and memory formation. However, the functional relevance of immunoproteasomes in the healthy brain and especially their impact on normal brain function including processes of learning and memory has not been investigated so far. In the present study, we analyzed the phenotypic effects of an impaired immunoproteasome formation using a β5i/LMP7-deficient mouse model in different behavioral paradigms focusing on locomotor activity, exploratory behavior, innate anxiety, startle response, prepulse inhibition, as well as fear and safety conditioning.
View Article and Find Full Text PDFThe relief from an aversive event is rewarding. Since organisms are able to learn which environmental cues can cease an aversive event, relief learning helps to better cope with future aversive events. Literature data suggest that relief learning is affected in various psychopathological conditions, such as anxiety disorders.
View Article and Find Full Text PDFNucleolar stress results when ribosome biogenesis is disrupted. An excellent example is the human Treacher Collins syndrome in which the loss of the nucleolar chaperone, Treacle, leads to p53-dependent apoptosis in embryonic neural crest cells and ultimately to craniofacial birth defects. Here, we show that depletion of the related nucleolar phosphoprotein, Nopp140, in Drosophila melanogaster led to nucleolar stress and eventual lethality when multiple tissues were depleted of Nopp140.
View Article and Find Full Text PDFThe identification and purification of murine multipotent mesenchymal stem cells (MSCs) have been difficult due to their low frequency, the presence of contaminating cell types and lack of unambiguous markers. Using a magnetic micro-beads negative selection technique to remove hematopoietic cells from mouse bone marrow stromal cells (BMSCs), our lab recently isolated a highly purified osteoprogenitor (HipOP) population that was also enriched for other mesenchymal precursors, including MSCs [Itoh and Aubin, 2009]. We now report that HipOPs are also highly enriched in vascular endothelial cells (VECs), which we hypothesized were an accessory cell type regulating osteogenesis.
View Article and Find Full Text PDFMorphine is a poor inducer of micro-opioid receptor (MOR) internalization, but a potent inducer of cellular tolerance. Here we show that, in contrast to full agonists such as [D-Ala(2)-MePhe(4)-Gly-ol]enkephalin (DAMGO), morphine stimulated a selective phosphorylation of the carboxy-terminal residue 375 (Ser(375)). Ser(375) phosphorylation was sufficient and required for morphine-induced desensitization of MOR.
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