Neuroscience
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The olfactory epithelium constitutes the sole source of regenerating neural cells that can be obtained from a living human. As such, primary cultures derived from human olfactory epithelial biopsies can be utilized to study neurobiological characteristics of individuals under different conditions and disease states. Here, using such human cultures, we report in vitro generation of cells that exhibit a complex neuronal phenotype, encompassing receptors and signaling pathways pertinent to both olfaction and other aspects of CNS function. ⋯ The array of neuronal characteristics observed here establishes that proliferating cells derived from the human olfactory epithelium differentiate in vitro to express functional and molecular attributes of mature olfactory neurons. These cultured neural cells exhibit neurotransmitter pathways important in a number of neuropsychiatric disorders. Their ready availability from living humans thus provides a new tool to link functional and molecular features of neural cells with clinical characteristics of individual living patients.
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Lack of sexual interest is the most common sexual complaint among women. However, factors affecting sexual desire in women have rarely been studied. While the role of the brain in integrating the sensory, attentional, motivational, and motor aspects of sexual response is commonly acknowledged as important, little is known about specific patterns of brain activation and sexual interest or response, particularly among women. ⋯ Findings were consistent across the three experimental sessions. The results suggest differences between women with NHSD and HSDD in encoding arousing stimuli, retrieval of past erotic experiences, or both. The findings of greater activation in BA 10 and BA 47 among women with HSDD suggest that this group allocated significantly more attention to monitoring and/or evaluating their responses than NHSD participants, which may interfere with normal sexual response.
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One way of investigating affective learning is the use of aversive pictures as unconditioned stimuli (UCS) in conditioning paradigms. In the last decades, there has been a heated debate on the influence of contingency awareness on conditioned responses (CRs). Only a few studies found CRs in contingency unaware subjects whereas other studies only reported conditioned reactions in contingency aware participants. ⋯ Investigation of SCRs and valence ratings revealed that only aware participants showed conditioned reactions. Our results point toward dissociations between response levels (e.g. brain activity) not affected by contingency awareness and more cognitive response levels (e.g. subjective ratings and SCRs) which are affected by contingency awareness. As a unique finding in human aversive conditioning, we discuss the role of the nucleus accumbens as well as practical implications for affective learning models.
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The endocannabinoid system is a neuromodulatory system which controls the release of multiple neurotransmitters, including glutamate and both, the endocannabinoid and glutamatergic systems, have been implicated in alcohol relapse. Cannabinoid agonists induce an increase in relapse-like drinking whereas glutamate receptor antagonists could prevent it. Here we hypothesize that cannabinoid-induced increases in relapse-like alcohol drinking could be mediated by glutamatergic N-methyl-d-aspartate (NMDA) receptors. ⋯ Interestingly, such changes were blocked after L-701 treatment. Finally, WIN treatment also caused a reduction in NR1 mRNA levels in the amygdala. In conclusion, pharmacological inactivation of the glycine-binding site of NMDA receptors may control cannabinoid-induced relapse-like drinking, which is associated with altered expression of CNR1 and NR1 gene expression as observed after WIN treatment.
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Memory consolidation and reconsolidation in an invertebrate model: the role of the GABAergic system.
Consolidation theory assumes that memories are labile during a limited time window after acquisition, but as time passes, memories become stable and resistant to amnesic agents. However, the vision of immutable memories after consolidation has been challenged. Thus, after the presentation of a reminder, the reactivated old memories become labile and again susceptible to amnesic treatments. ⋯ The ubiquity of the neurotransmitter and its receptors in the animal taxa allows us to use the classic agonist-and-antagonist administration procedure in this invertebrate. Thus, all the results reported in this paper can be judged as a result of the modulation exerted by the functional state of the GABAergic system in the CNS. To conclude, the results obtained in this report with an invertebrate model represent additional evidences supporting the view that some molecular mechanisms subserving different memory phases could be the basic tools employed by phylogenetically disparate animals.