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1.
Learn Behav ; 50(3): 339-348, 2022 09.
Article in English | MEDLINE | ID: mdl-35112315

ABSTRACT

In order to effectively thwart predation, antipredator defensive behaviors must be matched to the current spatio-temporal relationship to the predator. We have proposed a model where different defensive responses are organized along a predatory imminence continuum (PIC). The PIC is a behavior system organized as a sequence of innately programmed behavioral modes, each representing a different interaction with the predator or threat. Ranging from low threat to predator contact, the PIC categorizes defense modes as pre-encounter, post-encounter, and circa-strike, corresponding to states of anxiety, fear, and panic, respectively. This experiment examined if the same significant stressor caused overexpression of all defensive responses along the PIC, including anxiety-like behavior, freezing, and panic-like responses. Female and male mice were exposed to acute stress that consisted of a series of ten pseudorandomly presented unsignaled footshocks (or no shocks). Mice were subsequently tested on a battery of tasks to assess stress effects on pre-encounter (anxiety-like), post-encounter (fear), and circa-strike (panic-like) behaviors. Results revealed that following stress, mice exhibited increased anxiety-like behavior shown through reduced average velocity within a modified open field. Furthermore, stressed mice showed increased fear following a single footshock in a new context as well as an increase in reactivity to white noise in the original stress context, with stressed mice exhibiting a more robust circa-strike-like response than controls. Therefore, significant stress exposure influenced the defensive states of anxiety, fear, and panic across the predatory imminence continuum. This research could therefore reveal how such responses become maladaptive following traumatic stress in humans.


Subject(s)
Fear , Predatory Behavior , Animals , Anxiety , Behavior, Animal/physiology , Fear/physiology , Female , Humans , Male , Mice , Predatory Behavior/physiology
2.
Behav Pharmacol ; 30(2 and 3-Spec Issue): 115-121, 2019 04.
Article in English | MEDLINE | ID: mdl-30640181

ABSTRACT

Most people have or will experience traumatic stress at some time over the lifespan, but only a subset of traumatized individuals develop post-traumatic stress disorder (PTSD). Clinical research supports high rates of traumatic brain injury (TBI)-PTSD comorbidity and demonstrates TBI as a significant predictor of the development of PTSD. Biological factors impacted following brain injury that may contribute to increased PTSD risk are unknown. Heightened stress reactivity and dysregulated hypothalamic-pituitary-adrenal (HPA) axis function are common to both TBI and PTSD, and affect amygdalar structure and function, which is implicated in PTSD. In this review, we summarize a growing body of literature that shows HPA axis dysregulation, as well as enhanced fear and amygdalar function after TBI. We present the hypothesis that altered stress reactivity as a result of brain injury impacts the amygdala and defense systems to be vulnerable to increased fear and PTSD development from traumatic stress. Identifying biological mechanisms that underlie this vulnerability, such as dysregulated HPA axis function, may lead to better targeted treatments and preventive measures to support psychological health after TBI.


Subject(s)
Brain Injuries, Traumatic/physiopathology , Stress Disorders, Post-Traumatic/physiopathology , Stress Disorders, Post-Traumatic/psychology , Amygdala/metabolism , Brain/metabolism , Comorbidity , Fear/psychology , Humans , Hypothalamo-Hypophyseal System/metabolism , Pituitary-Adrenal System/metabolism , Stress Disorders, Post-Traumatic/metabolism , Stress, Physiological/physiology
3.
Anal Biochem ; 559: 30-33, 2018 10 15.
Article in English | MEDLINE | ID: mdl-30142329

ABSTRACT

Aggregated compounds can promiscuously and nonspecifically associate with proteins resulting in either false inhibition or activation of many different protein target classes. We developed a high-content imaging assay in a 384-well format using fluorescently labeled target proteins and an Operetta cell imager to screen for compound aggregates that interact with target proteins. The high-throughput assay can not only directly detect the interaction between compound aggregators and the target of interest, but also determine the critical aggregation concentration (CAC) of a given promiscuous small molecule.


Subject(s)
Fluorescent Dyes/chemistry , High-Throughput Screening Assays , Optical Imaging , Proteins/chemistry , Humans , Particle Size , Protein Aggregates , Surface Properties
4.
J Nurs Adm ; 48(11): 580-584, 2018 Nov.
Article in English | MEDLINE | ID: mdl-30320625

ABSTRACT

OBJECTIVE: The aim of this study was to examine nurses' perceptions regarding the resources needed during floating. BACKGROUND: Most studies report on patterns of floating and the characteristics of float pool nurses. No studies exist regarding staff nurses' views of the types of resources needed to support floating. METHODS: Staff nurses in a pediatric hospital (N = 220) completed an electronic survey of both open- and close-ended questions. Close-ended data were analyzed with frequencies and percentages. Open-ended data were content-analyzed and then frequencies and percentages of categories of responses were performed. χ Analyses were used to examine relationships between the variables. RESULTS: There were no significant relationships between resources and years at the institution and number of times floated in past year. The top 3 categories of resources needed to float by nurse participants included having an assigned a resource/buddy, mini-orientation, and electronic updates about the units they are floating to. CONCLUSIONS: These findings underscore common frustrations nurses experience during floating and ways that nurse executives can create a more satisfactory floating environment and increase nursing satisfaction.

5.
Jt Comm J Qual Patient Saf ; 43(4): 166-175, 2017 Apr.
Article in English | MEDLINE | ID: mdl-28325204

ABSTRACT

BACKGROUND: As the health care system in the United States places greater emphasis on the public reporting of quality and safety data and its use to determine payment, provider organizations must implement structures that ensure discipline and rigor regarding these data. An academic health system, as part of a performance management system, applied four key components of a financial reporting structure to support the goal of top-to-bottom accountability for improving quality and safety. FOUR KEY COMPONENTS OF A FINANCIAL REPORTING STRUCTURE: The four components implemented by Johns Hopkins Medicine were governance, accountability, reporting of consolidated quality performance statements, and auditing. Governance is provided by the health system's Patient Safety and Quality Board Committee, which reviews goals and strategy for patient safety and quality, reviews quarterly performance for each entity, and holds organizational leaders accountable for performance. An accountability plan includes escalating levels of review corresponding to the number of months an entity misses the defined performance target for a measure. A consolidated quality statement helps inform the Patient Safety and Quality Board Committee and leadership on key quality and safety issues. An audit evaluates the efficiency and effectiveness of processes for data collection, validation, and storage, as to ensure the accuracy and completeness of quality measure reporting. CONCLUSION: If hospitals and health systems truly want to prioritize improvements in safety and quality, they will need to create a performance management system that ensures data validity and supports performance accountability. Without valid data, it is difficult to know whether a performance gap is due to data quality or clinical quality.


Subject(s)
Delivery of Health Care/organization & administration , Economics, Hospital , Financial Management , Quality of Health Care , Accounting/standards , Clinical Audit , Delivery of Health Care/economics , Delivery of Health Care/standards , Health Care Sector/economics , Health Care Sector/organization & administration , Health Services Research , Hospitals/standards , Humans , Maryland , Patient Safety , United States
6.
Neurobiol Learn Mem ; 120: 61-8, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25732249

ABSTRACT

The chronically stressed brain may present a vulnerability to develop maladaptive fear-related behaviors in response to a traumatic event. In rodents, chronic stress leads to amygdala hyperresponsivity and dendritic hypertrophy and produces a post traumatic stress disorder (PTSD)-like phenotype that includes exaggerated fear learning following Pavlovian fear conditioning and resistance to extinction. It is unknown whether chronic stress-induced enhanced fear memories are vulnerable to disruption via reconsolidation blockade, as a novel therapeutic approach for attenuating exaggerated fear memories. We used a chronic stress procedure in a rat model (wire mesh restraint for 6h/d/21d) to create a vulnerable brain that leads to a PTSD-like phenotype. We then examined freezing behavior during acquisition, reactivation and after post-reactivation rapamycin administration (i.p., 40mg/kg) in a Pavlovian fear conditioning paradigm to determine its effects on reconsolidation as well as the subsequent functional activation of limbic structures using zif268 mRNA. Chronic stress increased amygdala zif268 mRNA during fear memory retrieval at reactivation. Moreover, these enhanced fear memories were unaffected by post reactivation rapamycin to disrupt long-term fear memory. Also, post-reactivation long term memory processing was also associated with increased amygdala (LA and BA), and decreased hippocampal CA1 zif268 mRNA expression. These results suggest potential challenges for reconsolidation blockade as an effective approach in treating exaggerated fear memories, as in PTSD. Our findings also support chronic stress manipulations combined with fear conditioning as a useful preclinical approach to study a PTSD-like phenotype.


Subject(s)
Amygdala/physiology , Early Growth Response Protein 1/physiology , Fear/physiology , Memory Consolidation/physiology , Memory/physiology , Stress, Psychological/physiopathology , Amygdala/chemistry , Animals , Conditioning, Classical , Early Growth Response Protein 1/analysis , In Situ Hybridization , Male , RNA, Messenger/analysis , Rats , Rats, Sprague-Dawley
7.
Eur J Neurosci ; 40(9): 3351-62, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25156382

ABSTRACT

Chronic restraint stress impairs hippocampal-mediated spatial learning and memory, which improves following a post-stress recovery period. Here, we investigated whether brain-derived neurotrophic factor (BDNF), a protein important for hippocampal function, would alter the recovery from chronic stress-induced spatial memory deficits. Adult male Sprague-Dawley rats were infused into the dorsal hippocampal cornu ammonis (CA)3 region with an adeno-associated viral vector containing the sequence for a short hairpin RNA (shRNA) directed against BDNF or a scrambled sequence (Scr). Rats were then chronically restrained (wire mesh, 6 h/day for 21 days) and assessed for spatial learning and memory using a radial arm water maze (RAWM) either immediately after stressor cessation (Str-Imm) or following a 21-day post-stress recovery period (Str-Rec). All groups learned the RAWM task similarly, but differed on the memory retention trials. Rats in the Str-Imm group, regardless of adeno-associated viral contents, committed more errors in the spatial reference memory domain on the single retention trial during day 3 than did the non-stressed controls. Importantly, the typical improvement in spatial memory following the recovery from chronic stress was blocked with the shRNA against BDNF, as Str-Rec-shRNA performed worse on the RAWM compared with the non-stressed controls or Str-Rec-Scr. The stress effects were specific for the reference memory domain, but knockdown of hippocampal BDNF in unstressed controls briefly disrupted spatial working memory as measured by repeated entry errors on day 2 of training. These results demonstrated that hippocampal BDNF was necessary for the recovery from stress-induced hippocampal-dependent spatial memory deficits in the reference memory domain.


Subject(s)
Brain-Derived Neurotrophic Factor/metabolism , CA3 Region, Hippocampal/metabolism , Spatial Memory/physiology , Stress, Psychological/metabolism , Animals , Down-Regulation , Male , Rats , Rats, Sprague-Dawley , Restraint, Physical
8.
Neurobiol Learn Mem ; 112: 139-47, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24508064

ABSTRACT

Chronic stress may impose a vulnerability to develop maladaptive fear-related behaviors after a traumatic event. Whereas previous work found that chronic stress impairs the acquisition and recall of extinguished fear, it is unknown how chronic stress impacts nonassociative fear, such as in the absence of the conditioned stimulus (CS) or in a novel context. Male rats were subjected to chronic stress (STR; wire mesh restraint 6 h/d/21d) or undisturbed (CON), then tested on fear acquisition (3 tone-footshock pairings), and two extinction sessions (15 tones/session) within the same context. Then each group was tested (6 tones) in the same context (SAME) or a novel context (NOVEL), and brains were processed for functional activation using Fos immunohistochemistry. Compared to CON, STR showed facilitated fear acquisition, resistance to CS extinction on the first extinction day, and robust recovery of fear responses on the second extinction day. STR also showed robust freezing to the context alone during the first extinction day compared to CON. When tested in the same or a novel context, STR exhibited higher freezing to context than did CON, suggesting that STR-induced fear was independent of context. In support of this, STR showed increased Fos-like expression in the basolateral amygdala and CA1 region of the hippocampus in both the SAME and NOVEL contexts. Increased Fos-like expression was also observed in the central amygdala in STR-NOVEL vs. CON-NOVEL. These data demonstrate that chronic stress enhances fear learning and impairs extinction, and affects nonassociative processes as demonstrated by enhanced fear in a novel context.


Subject(s)
Amygdala/metabolism , Extinction, Psychological/physiology , Fear/physiology , Generalization, Psychological/physiology , Hippocampus/metabolism , Proto-Oncogene Proteins c-fos/biosynthesis , Stress Disorders, Post-Traumatic/etiology , Stress, Psychological/complications , Animals , Chronic Disease , Conditioning, Psychological/physiology , Disease Models, Animal , Freezing Reaction, Cataleptic/physiology , Male , Rats , Rats, Sprague-Dawley , Stress, Psychological/metabolism
9.
Am Psychol ; 2024 May 02.
Article in English | MEDLINE | ID: mdl-38695781

ABSTRACT

We describe the close correspondence between predatory imminence continuum theory (PICT) and the National Institute of Mental Health's Research Domain Criteria (RDoC) for negative valence. RDoC's negative valence constructs relate aversively motivated behavioral reactions to various levels of threat. PICT divides defensive responses into distinct modes that vary along a continuum of the psychological closeness of predatory threat. While there is a close correspondence between PICT modes and negative valence threat constructs, based on PICT, we describe some potential elaborations of RDoC constructs. Both have consonant views of fear and anxiety and provide explicit distinctions between these emotional states, relating them to specific defensive behaviors and functions. We describe recent data that causally implicate human subjective emotional states with amygdala activity, which is also critical for defensive behavior. We conclude that attention to neuroethological views of defense can advance our understanding of the etiology and treatment of anxiety and stress disorders. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

10.
Mol Pharmacol ; 83(1): 283-93, 2013 Jan.
Article in English | MEDLINE | ID: mdl-23115324

ABSTRACT

Epigenetic alterations, such as histone acetylation, regulate the signaling outcomes and phenotypic responses of fibroblasts after growth factor stimulation. The bromodomain and extra-terminal domain-containing proteins (Brd) bind to acetylated histone residues, resulting in recruitment of components of the transcriptional machinery and subsequent gene transcription. Given the central importance of fibroblasts in tissue fibrosis, this study sought to determine the role of Brd proteins in human lung fibroblasts (LFs) after growth factor stimulation and in the murine bleomycin model of lung fibrosis. Using small interfering RNA against human Brd2 and Brd4 and pharmacologic Brd inhibitors, this study found that Brd2 and Brd4 are essential in mediating the phenotypic responses of LFs downstream of multiple growth factor pathways. Growth factor stimulation of LFs causes increased histone acetylation, association of Brd4 with growth factor-responsive genes, and enhanced transcription of these genes that could be attenuated with pharmacologic Brd inhibitors. Of note, lung fibrosis induced after intratracheal bleomycin challenge in mice could be prevented by pretreatment of animals with pharmacologic inhibitors of Brd proteins. This study is the first demonstration of a role for Brd2 and Brd4 proteins in mediating the responses of LFs after growth factor stimulation and in driving the induction of lung fibrosis in mice in response to bleomycin challenge.


Subject(s)
Fibroblasts/physiology , Lung/metabolism , Nuclear Proteins/metabolism , Protein Serine-Threonine Kinases/metabolism , Proto-Oncogene Proteins c-sis/pharmacology , Pulmonary Fibrosis/metabolism , Transcription Factors/metabolism , Transforming Growth Factor beta1/pharmacology , Actins/biosynthesis , Administration, Oral , Animals , Becaplermin , Bleomycin , Cell Cycle Proteins , Cell Movement , Cell Proliferation , Cytokines/metabolism , Epigenesis, Genetic , Extracellular Matrix Proteins/biosynthesis , Fibroblasts/drug effects , Humans , Lung/drug effects , Lung/pathology , Male , Mice , Mice, Inbred C57BL , Nuclear Proteins/antagonists & inhibitors , Nuclear Proteins/genetics , Protein Serine-Threonine Kinases/antagonists & inhibitors , Protein Serine-Threonine Kinases/genetics , Proto-Oncogene Proteins c-sis/metabolism , Pulmonary Fibrosis/chemically induced , Pulmonary Fibrosis/prevention & control , RNA, Small Interfering/genetics , Transcription Factors/antagonists & inhibitors , Transcription Factors/genetics , Transcription, Genetic , Transforming Growth Factor beta1/metabolism
11.
Bioinformatics ; 28(3): 301-5, 2012 Feb 01.
Article in English | MEDLINE | ID: mdl-22155864

ABSTRACT

MOTIVATION: Cell-based phenotypic screens using small molecule inhibitors is an important technology for early drug discovery if the relationship between the disease-related cellular phenotype and inhibitors' biological targets can be determined. However, chemical inhibitors are rightfully believed to be less specific than perturbation by biological agents, such as antibody and small inference RNA. Therefore, it is often a challenge in small molecule phenotypic screening to infer the causality between a particular cellular phenotype and the inactivation of the responsible protein due to the off-target effect of the inhibitors. RESULTS: In this article, we present a Roche in-house effort of screening 746 structurally diverse compounds for their cytotoxicity in HeLa cells measured by high content imaging technology. These compounds were also systematically profiled for the targeted and off-target binding affinity to a panel of 25 pre-selected protein kinases in a cell-free system. In an effort to search for the kinases whose activities are crucial for cell survival, we found that the simple association method such as the chi-square test yields a large number of false positives because the observed cytotoxic phenotype is likely to be the result of promiscuous action of less specific inhibitors instead of true consequence of inactivation of single relevant target. We demonstrated that a stratified categorical data analysis technique such as the Cochran-Mantel-Haenszel test is an effective approach to extract the meaningful biological connection from the spurious correlation resulted from confounding covariates. This study indicates that, empowered by appropriate statistical adjustment, small molecule inhibitor perturbation remains a powerful tool to pin down the relevant biomarker for drug safety and efficacy research. CONTACT: xin.wei@roche.com SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Subject(s)
Drug Discovery/methods , High-Throughput Screening Assays , Protein Kinase Inhibitors/pharmacology , Cell Survival , Cell-Free System , HeLa Cells , Humans
12.
Stress ; 16(5): 587-91, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23662914

ABSTRACT

Stressors are typically multidimensional, comprised of multiple physical and sensory components that rarely occur as single isolated events. This study used a 2-day stress exposure paradigm to assess functional activation patterns (by Fos expression) in key corticolimbic structures following repeated context, repeated restraint, context followed by restraint or restraint followed by context. On day 1, rats were transported to a novel context and either restrained for 6 h or left undisturbed. On day 2, these two groups were either restrained or not in the same context, then processed for Fos immunohistochemistry. Regardless of prior stress experience, rats exposed to context only on day 2 expressed more Fos-like immunoreactive (IR) labeling in CA1 and CA3 of dorsal hippocampus, basolateral amygdala and central amygdala than those that were not. This pattern was reversed in the dentate gyrus infrapyramidal blade. In contrast, in the infralimbic region of the medial prefrontal cortex (mPFC), the experience of a single restraint on either day 1 or day 2 rats elevated Fos-like IR relative to rats that had been exposed to context alone. These data show that exposure to context produces robust Fos induction in the hippocampus and amygdala, regardless of prior experience with restraint and compared to the immediate experience of restraint, with prior experience modulating Fos expression within the mPFC.


Subject(s)
Amygdala/metabolism , CA1 Region, Hippocampal/metabolism , CA3 Region, Hippocampal/metabolism , Dentate Gyrus/metabolism , Prefrontal Cortex/metabolism , Proto-Oncogene Proteins c-fos/biosynthesis , Animals , Genes, Immediate-Early/physiology , Immunohistochemistry , Male , Rats , Restraint, Physical , Stress, Physiological , Stress, Psychological
13.
Eur J Neurosci ; 36(8): 3086-95, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22758646

ABSTRACT

After natural menopause in women, androstenedione becomes the primary hormone secreted by the residual follicle-depleted ovaries. In two independent studies, in rodents that had undergone ovarian follicular depletion, we found that higher endogenous serum androstenedione levels correlated with increased working memory errors. This led to the hypothesis that higher androstenedione levels impair memory. The current study directly tested this hypothesis, examining the cognitive effects of exogenous androstenedione administration in rodents. Middle-aged ovariectomised rats received vehicle or one of two doses of androstenedione. Rats were tested on a spatial working and reference memory maze battery including the water-radial arm maze, Morris water maze (MM) and delay match-to-sample task. Androstenedione at the highest dose impaired reference memory as well as the ability to maintain performance as memory demand was elevated. This was true for both high temporal demand memory retention of one item of spatial information, as well as the ability to handle multiple items of spatial working memory information. We measured glutamic acid decarboxylase (GAD) protein in multiple brain regions to determine whether the gamma-aminobutyric acid (GABA) system relates to androstenedione-induced memory impairments. Results showed that higher entorhinal cortex GAD levels were correlated with worse MM performance, irrespective of androstenedione treatment. These findings suggest that androstenedione, the main hormone produced by the follicle-depleted ovary, is detrimental to working memory, reference memory and memory retention. Furthermore, while spatial reference memory performance might be related to the GABAergic system, it does not appear to be altered with androstenedione administration, at least at the doses used in the current study.


Subject(s)
Androstenedione/blood , Memory Disorders/blood , Animals , Entorhinal Cortex/metabolism , Female , Glutamate Decarboxylase/metabolism , Maze Learning , Memory Disorders/metabolism , Memory Disorders/physiopathology , Memory, Short-Term , Menopause/blood , Menopause/physiology , Ovariectomy , Rats , Rats, Inbred F344 , Retention, Psychology
14.
Elife ; 112022 05 26.
Article in English | MEDLINE | ID: mdl-35616523

ABSTRACT

Fear conditioning is one of the most frequently used laboratory procedures for modeling learning and memory generally, and anxiety disorders in particular. The conditional response (CR) used in the majority of fear conditioning studies in rodents is freezing. Recently, it has been reported that under certain conditions, running, jumping, or darting replaces freezing as the dominant CR. These findings raise both a critical methodological problem and an important theoretical issue. If only freezing is measured but rodents express their learning with a different response, then significant instances of learning, memory, or fear may be missed. In terms of theory, whatever conditions lead to these different behaviors may be a key to how animals transition between different defensive responses and different emotional states. In mice, we replicated these past results but along with several novel control conditions. Contrary to the prior conclusions, running and darting were primarily a result of nonassociative processes and were actually suppressed by associative learning. Darting and flight were taken to be analogous to nonassociative startle or alpha responses that are potentiated by fear. Additionally, associative processes had some impact on the topography of flight behavior. On the other hand, freezing was the purest reflection of associative learning. We also uncovered a rule that describes when these movements replace freezing: when afraid, freeze until there is a sudden novel change in stimulation, then burst into vigorous flight attempts. This rule may also govern the change from fear to panic.


Subject(s)
Conditioning, Classical , Fear , Animals , Conditioning, Classical/physiology , Fear/physiology , Freezing , Learning , Mice
15.
Front Syst Neurosci ; 16: 886771, 2022.
Article in English | MEDLINE | ID: mdl-35694043

ABSTRACT

External threats are a major source of our experience of negatively valanced emotion. As a threat becomes closer and more real, our specific behavior patterns and our experiences of negative affect change in response to the perceived imminence of threat. Recognizing this, the National Institute of Mental Health's Research Domain Criteria (RDoC) Negative Valence system is largely based around different levels of threat imminence. This perspective describes the correspondence between the RDoC Negative Valence System and a particular neurobiological/neuroecological model of reactions to threat, the Predatory Imminence Continuum (PIC) Theory. Using the COVID-19 pandemic as an illustration, we describe both adaptive and maladaptive behavior patterns from this perspective to illustrate how behavior in response to a crisis may get shaped. We end with suggestions on how further consideration of the PIC suggests potential modifications of the negative valence systems RDoC.

16.
J Neurotrauma ; 39(21-22): 1561-1574, 2022 11.
Article in English | MEDLINE | ID: mdl-35722903

ABSTRACT

Cognitive impairments and emotional lability are common long-term consequences of traumatic brain injury (TBI). How TBI affects interactions between sensory, cognitive, and emotional systems may reveal mechanisms that underlie chronic mental health comorbidities. Previously, we reported changes in auditory-emotional network activity and enhanced fear learning early after TBI. In the current study, we asked whether TBI has long-term effects on fear learning and responses to novel stimuli. Four weeks following lateral fluid percussion injury (FPI) or sham surgery, adult male rats were fear conditioned to either white noise-shock or tone-shock pairing, or shock-only control and subsequently were tested for freezing to context and to the trained or novel auditory cues in a new context. FPI groups showed greater freezing to their trained auditory cue, indicating long-term TBI enhanced fear. Interestingly, FPI-Noise Shock animals displayed robust fear to the novel, untrained tone compared with Sham-Noise Shock across both experiments. Shock Only groups did not differ in freezing to either auditory stimulus. These findings suggest that TBI precipitates maladaptive associative fear generalization rather than non-associative sensitization. Basolateral amygdala (BLA) α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAr) subunits GluA1 and GluA2 levels were analyzed and the FPI-Noise Shock group had increased GluA1 (but not GluA2) levels that correlated with the level of tone fear generalization. This study illustrates a unique chronic TBI phenotype with both a cognitive impairment and increased fear and possibly altered synaptic transmission in the amygdala long after TBI, where stimulus generalization may underlie maladaptive fear and hyperarousal.


Subject(s)
Brain Injuries, Traumatic , Brain Injury, Chronic , Fear , Receptors, AMPA , Animals , Male , Rats , Amygdala/metabolism , Brain Injuries, Traumatic/metabolism , Fear/psychology , Receptors, AMPA/metabolism
17.
Front Rehabil Sci ; 3: 1064215, 2022.
Article in English | MEDLINE | ID: mdl-36684686

ABSTRACT

In survivors of moderate to severe traumatic brain injury (msTBI), affective disruptions often remain underdetected and undertreated, in part due to poor understanding of the underlying neural mechanisms. We hypothesized that limbic circuits are integral to affective dysregulation in msTBI. To test this, we studied 19 adolescents with msTBI 17 months post-injury (TBI: M age 15.6, 5 females) as well as 44 matched healthy controls (HC: M age 16.4, 21 females). We leveraged two previously identified, large-scale resting-state (rsfMRI) networks of the amygdala to determine whether connectivity strength correlated with affective problems in the adolescents with msTBI. We found that distinct amygdala networks differentially predicted externalizing and internalizing behavioral problems in patients with msTBI. Specifically, patients with the highest medial amygdala connectivity were rated by parents as having greater externalizing behavioral problems measured on the BRIEF and CBCL, but not cognitive problems. The most correlated voxels in that network localize to the rostral anterior cingulate (rACC) and posterior cingulate (PCC) cortices, predicting 48% of the variance in externalizing problems. Alternatively, patients with the highest ventrolateral amygdala connectivity were rated by parents as having greater internalizing behavioral problems measured on the CBCL, but not cognitive problems. The most correlated voxels in that network localize to the ventromedial prefrontal cortex (vmPFC), predicting 57% of the variance in internalizing problems. Both findings were independent of potential confounds including ratings of TBI severity, time since injury, lesion burden based on acute imaging, demographic variables, and other non-amygdalar rsfMRI metrics (e.g., rACC to PCC connectivity), as well as macro- and microstructural measures of limbic circuitry (e.g., amygdala volume and uncinate fasciculus fractional anisotropy). Supporting the clinical significance of these findings, patients with msTBI had significantly greater externalizing problem ratings than healthy control participants and all the brain-behavior findings were specific to the msTBI group in that no similar correlations were found in the healthy control participants. Taken together, frontoamygdala pathways may underlie chronic dysregulation of behavior and mood in patients with msTBI. Future work will focus on neuromodulation techniques to directly affect frontoamygdala pathways with the aim to mitigate such dysregulation problems.

18.
Neurotrauma Rep ; 2(1): 200-213, 2021.
Article in English | MEDLINE | ID: mdl-33937912

ABSTRACT

Traumatic brain injury (TBI)-induced disruptions in synaptic function within brain regions and across networks in the limbic system may underlie a vulnerability for maladaptive plasticity and contribute to behavioral comorbidities. In this study we measured how synaptic proteins respond to lateral fluid percussion injury (FPI) brain regions known to regulate emotion and memory, including the basolateral amygdala (BLA), dorsal and ventral hippocampus (DH, VH), and medial prefrontal cortex (PFC). We investigated proteins involved in regulating plasticity, including synaptic glutamatergic a-amino-3-hydroxy5-methyl-4-isoxazolepropionic acid (AMPA; GluA1, GluA2) and N-methyl-D-aspartate (NMDA; NR1, NR2A, NR2B) receptor subunits as well as inhibitory gamma-aminobutyric acid (GABA) synthetic enzymes (GAD67, GAD65) via western blot. Adult male rats received a mild-moderate lateral FPI or sham surgery and ipsi- and contralateral BLA, DH, VH, and PFC were collected 6 h, 24 h, 48 h, and 7 days post-injury. In the ipsilateral BLA, there was a significant decrease in NR1 and GluA2 24 h after injury, whereas NR2A and NR2B were increased in the contralateral BLA at 48 h compared with sham. GAD67 was increased ipsilaterally at 24 h, but decreased contralaterally at 48 h in the BLA. In the DH, both NMDA (NR2A, NR2B) and GABA-synthetic (GAD65, GAD67) proteins were increased acutely at 6 h compared with sham. GAD67 was also robustly increased in the ipsilateral VH at 6 h. In the contralateral VH, NR2A significantly increased between 6 h and 24 h after FPI, whereas GAD65 was decreased across the same time-points in the contralateral VH. In the medial PFC at 24 h we saw bilateral increases in GAD67 and a contralateral decrease in GluA1. Later, there was a significant decrease in GAD67 in contralateral PFC from 48 h to 7 days post-injury. Collectively, these data suggest that lateral FPI causes a dynamic homeostatic response across limbic networks, leading to an imbalance of the proteins involved in plasticity in neural systems underlying cognitive and emotional regulation.

19.
J Dent Hyg ; 95(1): 57-66, 2021 Feb.
Article in English | MEDLINE | ID: mdl-33627454

ABSTRACT

Purpose: Quality of life is considered a component of patient centered care. The purpose of this study was to examine the relationship between self-reported oral health related quality of life (OHRQoL) and the actual oral health status of children.Methods: This retrospective cohort study consisted of pediatric dental chart reviews from three clinics. Demographic and dental visit data along with the child's OHRQoL utilizing the Pediatric Oral health-related Quality of Life (POQL) instrument, were collected. Associations with untreated decay, treated decay, or POQL score were tested, using Chi-square, Fisher's exact test, 2-sample t-tests, or ANOVA. Linear regression was used to evaluate the effect of statistical confounders in the relationship between untreated decay and POQL scores. Significance level was set to 0.05.Results: Two hundred ninety-seven out of 336 children had both POQL and caries data. White children and children with untreated decay had significantly more negative POQL scores. Children rating their oral health as "excellent" or "very good" and children with sealants on molars had significantly more positive POQLs. Associations between POQL scores were significant with untreated decay, but not sealants, when considering both variables in the same model. After adjusting for having sealants, POQL scores were on average 7.5 points higher (more negative) in children with untreated decay, than in children without decay (p<0.001).Conclusions: Collecting OHRQoL data allows oral health providers to easily incorporate patient perceptions in their assessment and care and would ensure that all oral health needs of the patients are being met. This is important for children, who may have difficulty expressing their concerns, particularly in clinical environments.


Subject(s)
Dental Caries , Quality of Life , Child , Dental Caries/epidemiology , Humans , Oral Health , Retrospective Studies , Self Report
20.
Neurobiol Learn Mem ; 94(3): 422-33, 2010 Oct.
Article in English | MEDLINE | ID: mdl-20807583

ABSTRACT

Chronic stress and estrogens alter many forebrain regions in female rats that affect cognition. In order to investigate how chronic stress and estrogens influence fear learning and memory, we ovariectomized (OVX) female Sprague-Dawley rats and repeatedly injected them (s.c.) with 17ß-estradiol (E, 10 µg/250 g or sesame oil vehicle, VEH). Concurrently, rats were restrained for 6 h/d/21 d (STR) or left undisturbed (CON). Rats were then fear conditioned with 4 tone-footshock pairings and then after 1 h and 24 h delays, given 15 tone extinction trials. Regardless of E treatment, chronic stress (VEH, E) facilitated freezing to tone during acquisition and extinction following a 1h delay, but not during extinction after a 24 h delay. E did not influence freezing to tone during any phase of fear conditioning for either the control or chronically stressed rats, but did influence contextual conditioning that may have been carried predominately by the STR group. In the second experiment, we investigated "handling" influences on fear conditioning acquisition, given the disparate findings from the current study and previous work (Baran, Armstrong, Niren, & Conrad, 2010; Baran, Armstrong, Niren, Hanna, & Conrad, 2009). Female rats remained gonadally-intact since E did not influence tone fear conditioning. Indeed, brief daily handling (1-3 m/d/21 d) facilitated acquisition of fear conditioning in chronically stressed female rats, and either had no effect or slightly attenuated fear conditioning in controls. Thus, chronic stress impacts amygdala-mediated fear learning in both OVX- and gonadally-intact females as found previously in males, with handling significantly influencing these outcomes.


Subject(s)
Association Learning/physiology , Conditioning, Classical/physiology , Estradiol/administration & dosage , Fear/physiology , Freezing Reaction, Cataleptic/physiology , Stress, Physiological/physiology , Analysis of Variance , Animals , Association Learning/drug effects , Conditioning, Classical/drug effects , Electroshock , Extinction, Psychological/drug effects , Extinction, Psychological/physiology , Fear/drug effects , Female , Freezing Reaction, Cataleptic/drug effects , Ovariectomy , Rats , Rats, Sprague-Dawley , Restraint, Physical
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