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A Bioinspired Astrocyte-Derived Coating Promotes the In Vitro Proliferation of Human Neural Stem Cells While Maintaining Their Stemness
Get PDFThe repair of neuronal tissue is a challenging process due to the limited proliferative capacity of neurons. Neural stem cells (NSCs) can aid in the regeneration process of neural tissue due to their high proliferation potential and capacity to differentiate into neurons. The therapeutic potential of these cells can only be achieved if sufficient cells are obtained without losing their differentiation potential. Toward this end, an astrocyte-derived coating (HAc) was evaluated as a promising substrate to promote the proliferation of NSCs. Mass spectroscopy and scanning electron microscopy were used to characterize the HAc. The proliferation rate and the expression of stemness and differentiation markers in NSCs cultured on the HAc were evaluated and compared to the responses of these cells to commonly used coating materials including Poly-L-Ornithine (PLO), and a Human Induced Pluripotent Stem Cell (HiPSC)-based coating. The use of the HAc promotes the in vitro cell growth of NSCs. The expression of the stemness markers Sox2 and Nestin, and the differentiation marker DCX in the HAc group was akin to the expression of these markers in the controls. In summary, HAc supported the proliferation of NSCs while maintaining their stemness and neural differentiation potential
Cocaine Diminishes Consolidation of Cued Fear Expression in Female Rats Through Interactions With Dopamine D2 Receptors
Get PDFIn addition to cocaine’s addictive properties, cocaine use may lead to heightened risk-taking behaviors in individuals despite potentially aversive consequences. One possible reason for this may be cocaine’s disruptive effect on aversive memory formation. The present study investigated the effects of cocaine on fear memory formation using a cued fear conditioning paradigm in female Sprague Dawley rats. On day 1, animals received tone-shock pairings and on day 2 (24 hours later) were returned to the fear chamber and tested for recall of fear memory. Fear was measured as percent time the animal spent freezing during the tone presentation. In Experiment 1 (n = 48), cocaine (15mg/kg; i.p.) was administered prior to or immediately after the conditioning trials to assess the effect of cocaine on fear memory acquisition and consolidation. To determine whether cocaine’s effects on memory consolidation are mediated by D2 receptors, the D2 receptor antagonist eticlopride (0.1mg/kg; i.p.) was administered concurrently with cocaine. No drugs were administered on test day. Results from Experiment 1 revealed that pre-training cocaine diminishes fear acquisition and that post-conditioning cocaine resulted in diminished fear expression during fear test. Concurrent D2 antagonism attenuated the impairing effect of cocaine on fear memory consolidation, with animals showing increased freezing relative to animals receiving cocaine alone. In Experiment 2 (n = 15), animals received direct infusions of eticlopride (0.05 μl/min) into the ventral hippocampus (VH), a structure known to be involved in cued fear conditioning and a target region of ventral tegmental area, substantia nigra, and locus coeruleus dopaminergic neurons. Intra-VH eticlopride or saline was directly infused into the VH immediately after conditioning concurrent to cocaine administration. Results from Experiment 2 suggest that the antagonism of VH D2 receptors may disrupt the impairing effects of cocaine on fear memory consolidation, suggesting the VH as a potential region mediating this effect. The present study provides evidence that acute cocaine administration impairs aversive memory formation and establishes a potential circuit through which cocaine induces its detrimental effects on fear memory consolidation. Moreover, these results provide insight into why cocaine users might engage in impulsive and risk-taking behavior that could lead to fatal consequences
Exploring Surface-Induced Protein Folding of Amyloidogenic Proteins on Neuronal Membrane Surfaces using Molecular Dynamics Simulations
Get PDFSelf-aggregation and misfolding of two major amyloidogenic proteins, tau and human islet amyloid polypeptide (hIAPP), have been implemented in the pathogenesis of Alzheimer’s disease, yet the exact mechanisms remain unknown. It has been suggested that the small oligomers are more toxic than mature fibrils, but the mechanisms of membrane disruption are unknown. Using molecular dynamics (MD) simulations, the membrane-binding and protein-folding behaviors of these amyloidogenic proteins were investigated. Using both coarse-grained (CG) and atomistic MD simulations, we successfully model protein oligomers binding to specific and non-specific lipid rafts and the subsequent surface-induced protein folding. The tau simulations revealed that the membrane binding deficient mutant k18 fragment experienced surface-induced helical conformations while the wild type k18 fragment did not, which may speak to the difference in toxicity. With hIAPP, we found that there was a significant difference in protein folding between the different model membranes, suggesting that nonspecific membranes are most likely to promote helical conformations. In addition, monomeric hIAPP is less likely to experience formation of ordered structures when bound to GM1. The hybrid system did not demonstrate any preferential folding based on model membrane or size of oligomer. In general, this study provides new mechanistic insights about the protein folding of membrane-bound amyloidogenic proteins
‘One Piro man I knew well’: A brief commentary on An Amazonian Myth and its History
Get PDFThis is a book review for An Amazonian myth and History, to the special volume to honor Peter Gow
Doing Animal Studies with Androids, Aliens, and Ghosts: Defamiliarizing Human-Nonhuman Animal Relationships in Fiction
No full textExploring what can be learnt when literary critics in the field of animal studies temporarily direct attention away from representations of nonhuman animals in literature and towards liminal figures like androids, aliens and ghosts, this book examines the boundaries of humanness. Simultaneously, it encourages the reader both to see nonhuman animals afresh and to reimagine the terms of our relationships with them.Examining imaginative texts by writers such as Octavia Butler, Philip K. Dick, Kazuo Ishiguro, Jeanette Winterson and J. M. Coetzee, this book looks at depictions of androids that redefine traditional humanist qualities such as hope and uniqueness. It examines alien visions that unmask the racist and heteronormative roots of speciesism. And it unpacks examples of ghosts and spirits who offer posthumous visions of having-been-human that decenter anthropocentrism. In doing so, it leaves open the potential for better relationships and futures with nonhuman animals.https://digitalcommons.trinity.edu/mono/1191/thumbnail.jp
“Too many meanings”: reading “Piro designs”
Get PDFThis paper explores the notion of painting as meaningful action (Gow 1999) and highlights the productivity of the idea as emerging from, and dovetailing, different strands of thought on the nature of symbols and actions. Bringing together Lévi-Strauss’ intuition on the dynamism and generativity of graphic systems, phenomenological studies on meaning making, and ethnographic analyses of Amazonian theories of corporeality and sociality, Gow has shown how Yine (Piro) designs provide a developmental model that combines ontogenesis and social change. This paper argues for the productivity of this approach in Amerindian studies, in anthropology, and in a dialogue with psychoanalytic theory incipient in Peter Gow’s writings. It points at future research within the framework of returning to the centrality of objects and images as vehicles of people’s meaningful actions and processes in time
Amy Reed-Sandoval and Luis Rubén Díaz Cepeda, eds. Latin American Immigration Ethics [Review of the book \u3cem\u3eLatin American Immigration Ethics\u3c/em\u3e, by A. Reed-Sandoval & L. R. Díaz Cepeda, Eds.]
No full textEliciting Emotional Attachment: Jordan Brand and College Fan Purchasers
Get PDF: It is widely documented that emotions play an important role in product marketing and branding. The current study explores the role that a human brand association can play in eliciting emotional responses and attachments from consumers that drive their subsequent behaviour. The human-centred Jordan Brand was examined because it uses the likeness/image of Michael Jordan. The study revealed the impact of consumer responses and decision-making through survey analysis (N = 1,133) at two Jordan Brand partner university’s athletic events. The results demonstrate that the partnership between the university athletic department and Jordan Brand elicits strong emotional responses, the propensity to donate to the university, and increased consumer willingness to pay for merchandise bearing the human brand’s likeness. The findings are useful for both scholars and practitioners as evidence that strategies designed to elicit emotional responses can yield positive results in consumer perception of the brand and financial success
