91 research outputs found
Matrilineal behavioral and physiological changes following the death of a non-alpha matriarch in rhesus macaque
In many species, the loss of alpha matriarchs is associated with a number of negative outcomes such as troop fission, eviction, wounding, and reduced vitality. However, whether
the dramatic consequences of their loss are due to their role as an old experienced figure or
to their alpha status remains unclear. In a retrospective study, we tested that in a semi-free
ranging colony of rhesus macaques (Macaca mulatta), the removal of a non-alpha matriarch, who had a large set of kin, led to changes in behavior and physiological stress within
her matriline. Following her removal, her matriline increased in aggression, vigilance, and
social grooming. Additionally, hierarchical stability, measured by levels of rank changes,
decreased within her matriline, and levels of intense aggression by high-ranking animals
were more frequent, as well as matrilineal wounding. Although ordinal rank was positively
associated with higher chronic hair cortisol concentrations (HCCs) in the months before the
matriarch’s removal, following her removal, only those who experienced large increases in
rank within her matriline displayed higher HCCs. Changes in matrilineal stability, aggression, behavior, and HCCs within the other two matrilines in the troop were not evident,
although caution is needed due to the small sample sizes. We conclude that the removal of
the non-alpha matriarch led to matrilineal instability, characterized by higher levels of
aggression and subsequent vigilance, rank changes, physiological stress, and grooming.
We suggest that non-alpha matriarchs with a large number of kin and social support can be
integral to the stability of matrilines.Division of Intramural Research, National Institute of Child Health and Human Development, 1ZIAHD001107- 3
Resilient emotionality and molecular compensation in mice lacking the oligodendrocyte-specific gene Cnp1
Altered oligodendrocyte structure and function is implicated in major psychiatric illnesses, including low cell number and reduced oligodendrocyte-specific gene expression in major depressive disorder (MDD). These features are also observed in the unpredictable chronic mild stress (UCMS) rodent model of the illness, suggesting that they are consequential to environmental precipitants; however, whether oligodendrocyte changes contribute causally to low emotionality is unknown. Focusing on 2′-3′-cyclic nucleotide 3′-phosphodiesterase (Cnp1), a crucial component of axoglial communication dysregulated in the amygdala of MDD subjects and UCMS-exposed mice, we show that altered oligodendrocyte integrity can have an unexpected functional role in affect regulation. Mice lacking Cnp1 (knockout, KO) displayed decreased anxiety- and depressive-like symptoms (i.e., low emotionality) compared with wild-type animals, a phenotypic difference that increased with age (3–9 months). This phenotype was accompanied by increased motor activity, but was evident before neurodegenerative-associated motor coordination deficits (⩽9–12 months). Notably, Cnp1KO mice were less vulnerable to developing a depressive-like syndrome after either UCMS or chronic corticosterone exposure. Cnp1KO mice also displayed reduced fear expression during extinction, despite normal amygdala c-Fos induction after acute stress, together implicating dysfunction of an amygdala-related neural network, and consistent with proposed mechanisms for stress resiliency. However, the Cnp1KO behavioral phenotype was also accompanied by massive upregulation of oligodendrocyte- and immune-related genes in the basolateral amygdala, suggesting an attempt at functional compensation. Together, we demonstrate that the lack of oligodendrocyte-specific Cnp1 leads to resilient emotionality. However, combined with substantial molecular changes and late-onset neurodegeneration, these results suggest the low Cnp1 seen in MDD may cause unsustainable and maladaptive molecular compensations contributing to the disease pathophysiology
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An eye-movement study of relational memory in adults with Autism Spectrum Disorder
Persons with Autism Spectrum Disorder (ASD) demonstrate good memory for single items but difficulties remembering contextual information related to these items. Recently, we found compromised explicit but intact implicit retrieval of object-location information in ASD (Ring et al. 2015). Eye-movement data collected from a sub-sample of the participants are the focus of the current paper. At encoding, trial-by-trial viewing durations predicted subsequent retrieval success only in typically developing (TD) participants. During retrieval, TD compared to ASD participants looked significantly longer at previously studied objectlocations compared to alternative locations. These findings extend similar observations recently reported by Cooper et al. (2017a) and demonstrate that eye-movement data can shed important light on the source and nature of relational memory difficulties in ASD
Environmental enrichment requires adult neurogenesis to facilitate the recovery from psychosocial stress
The subgranular zone of the adult hippocampal dentate gyrus contains a pool of neural stem cells that continuously divide and differentiate into functional granule cells. It has been shown that production of new hippocampal neurons is necessary for amelioration of stress-induced behavioral changes by antidepressants in animal models of depression. The survival of newly born hippocampal neurons is decreased by chronic psychosocial stress and increased by exposure to enriched environments. These observations suggest the existence of a link between hippocampal neurogenesis, stress-induced behavioral changes, and the beneficial effects of enriched environment. To show causality, we subjected transgenic mice with conditionally suppressed neurogenesis to psychosocial stress followed by environmental enrichment. First, we showed that repeated social defeat coupled with chronic exposure to an aggressor produces robust and quantifiable indices of submissive and depressive-like behaviors; second, subsequent exposure to an enriched environment led to extinction of the submissive phenotype, while animals exposed to an impoverished environment retained the submissive phenotype; and third, enrichment was not effective in reversing the submissive and depressive-like behaviors in transgenic mice lacking neurogenesis. Our data show two main findings. First, living in an enriched environment is highly effective in extinguishing submissive behavioral traits developed during chronic social stress, and second, these effects are critically dependent on adult neurogenesis, indicating that beneficial behavioral adaptations are dependent on intact adult neurogenesis
Towards an understanding of medical student resilience in longitudinal integrated clerkships
Sulfonylated aminothiazoles as new small molecule inhibitors of protein phosphatases
Based on a previously identified lead structure, SC-ααδ9, we have developed a versatile new chemical scaffold that can be readily modified to generate libraries of both Tyr and dual specificity phosphatase inhibitors with reduced molecular weight and lipophilicity. The most potent analogue identified to date, aminothiazole 8z, inhibits the dual specificity phosphatase Cdc25B with a Ki of 4.6 ± 0.4 μM and a Hill coefficient of 2. © 2001 Elsevier Science Ltd
New inhibitors of the thioredoxin-thioredoxin reductase system based on a naphthoquinone spiroketal natural product lead
Natural products of the naphthoquinone spiroketal structural type served as lead structures for the development of novel inhibitors of the thioredoxin-thioredoxin reductase redox system. The most potent compound in this series inhibited thioredoxin with an IC50 of 350 nM, and many derivatives showed low micromolar activities for growth inhibition against two breast cancer cell lines. © 2001 Elsevier Science Ltd. All rights reserved
Identification of a potent and selective pharmacophore for Cdc25 dual specificity phosphatase inhibitors
Small molecules provide powerful tools to interrogate biological pathways but many important pathway participants remain refractory to inhibitors. For example, Cdc25 dual-specificity phosphatases regulate mammalian cell cycle progression and are implicated in oncogenesis, but potent and selective inhibitors are lacking for this enzyme class. Thus, we evaluated 10,070 compounds in a publicly available chemical repository of the National Cancer Institute for in vitro inhibitory activity against oncogenic, full-length, recombinant human Cdc25B. Twenty-one compounds had mean inhibitory concentrations of 75% were quinones and >40% were of the paranaphthoquinone structural type. Most notable was NSC 95397 (2,3-bis-[2-hydroxyethylsulfanyl]-[1,4]naphthoquinone), which displayed mixed inhibition kinetics with in vitro Ki values for Cdc25A, -B, and -C of 32, 96, and 40 nM, respectively. NSC 95397 was more potent than any inhibitor of dual specificity phosphatases described previously and 125- to 180-fold more selective for Cdc25A than VH1-related dual-specificity phosphatase or protein tyrosine phosphatase 1b, respectively. Modification of the bis-thioethanol moiety markedly decreased enzyme inhibitory activity, indicating its importance for bioactivity. NSC 95397 showed significant growth inhibition against human and murine carcinoma cells and blocked G2/M phase transition. A potential Cdc25 site of interaction was postulated based on molecular modeling with these quinones. We propose that inhibitors based on this chemical structure could serve as useful tools to probe the biological function of Cdc25
Fatal Septic Thrombosis of the Superior Sagittal Sinus After Face-lift Surgery Caused by Community-Associated Methicillin-Resistant Staphylococcus aureus
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