Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
1,068
result(s) for
"Bush, David"
Sort by:
Acquisition of Fear Extinction Requires Activation of NR2B-Containing NMDA Receptors in the Lateral Amygdala
N
-methyl-
D
-aspartate receptors (NMDARs) contribute to synaptic plasticity underlying learning in a variety of brain systems. Fear extinction, which involves learning to suppress the expression of previously learned fear, appears to require NMDAR activation in the amygdala. However, it is unclear whether amygdala NMDARs are required for the acquisition of extinction learning, and it is unknown whether NR2B-containing NMDARs are required in fear extinction. Here, we assessed the effects of selective NR2B blockade with ifenprodil on fear extinction learning, and found that both systemic and intra-amygdala ifenprodil treatment, given before extinction training, impaired the initial acquisition, and subsequent retrieval of fear extinction. These results confirm previous evidence showing that NMDARs in the amygdala are involved in fear extinction, and additionally show that NR2B-containing NMDARs are required. Contrary to the conclusion of previous studies, our findings demonstrate NMDARs are required for the initial acquisition, rather than only the retention, of fear extinction learning. Thus, our results support a previously not known role for NMDA-dependent plasticity in the lateral amygdala during the acquisition of fear extinction.
Journal Article
Sports coaching research : context, consequences, and consciousness
This volume raises critical questions about the explanatory framework guiding sports coaching research and presents a new conceptualisation for research in the field. The dominant or legitimate forms of coaching knowledge are identified and a new vision of the field, one which is more socially and culturally responsive, emerges.
Book
Implications of the 2019–2020 megafires for the biogeography and conservation of Australian vegetation
Australia’s 2019–2020 ‘Black Summer’ bushfires burnt more than 8 million hectares of vegetation across the south-east of the continent, an event unprecedented in the last 200 years. Here we report the impacts of these fires on vascular plant species and communities. Using a map of the fires generated from remotely sensed hotspot data we show that, across 11 Australian bioregions, 17 major native vegetation groups were severely burnt, and up to 67–83% of globally significant rainforests and eucalypt forests and woodlands. Based on geocoded species occurrence data we estimate that >50% of known populations or ranges of 816 native vascular plant species were burnt during the fires, including more than 100 species with geographic ranges more than 500 km across. Habitat and fire response data show that most affected species are resilient to fire. However, the massive biogeographic, demographic and taxonomic breadth of impacts of the 2019–2020 fires may leave some ecosystems, particularly relictual Gondwanan rainforests, susceptible to regeneration failure and landscape-scale decline.
Fires triggered by climate change threaten plant diversity in many biomes. Here the authors investigate how the catastrophic fires of 2019–2020 affected the vascular flora of SE Australia. They report that 816 species were highly impacted, including taxa of biogeographic and conservation interest.
Journal Article
Vietnam
Lonely Planet Vietnam is your passport to the most relevant, up-to-date advice on what to see and skip, and what hidden discoveries await you. Get happily lost in Hanoi's Old Quarter, paddle past Halong Bay's shimmering limestone peaks at dawn, or take a cooking class in charming Hoi An; all with your trusted travel companion. Get to the heart of Vietnam and begin your journey now!
Book
Heterogeneity in threat extinction learning: substantive and methodological considerations for identifying individual difference in response to stress
Pavlovian threat (fear) conditioning (PTC) is an experimental paradigm that couples innate aversive stimuli with neutral cues to elicit learned defensive behavior in response to the neutral cue. PTC is commonly used as a translational model to study neurobiological and behavioral aspects of fear and anxiety disorders including Posttraumatic Stress Disorder (PTSD). Though PTSD is a complex multi-faceted construct that cannot be fully captured in animals PTC is a conceptually valid model for studying the development and maintenance of learned threat responses. Thus, it can inform the understanding of PTSD symptomatology. However, there are significant individual differences in posttraumatic stress that are not as of yet accounted for in studies of PTC. Individuals exposed to danger have been shown to follow distinct patterns: some adapt rapidly and completely (resilience) others adapt slowly (recovery) and others failure to adapt (chronic stress response). Identifying similar behavioral outcomes in PTC increases the translatability of this model. In this report we present a flexible methodology for identifying individual differences in PTC by modeling latent subpopulations or classes characterized by defensive behavior during training. We provide evidence from a reanalysis of previously examined PTC learning and extinction data in rats to demonstrate the effectiveness of this methodology in identifying outcomes analogous to those observed in humans exposed to threat. By utilizing Latent Class Growth Analysis (LCGA) to test for heterogeneity in freezing behavior during threat conditioning and extinction learning in adult male outbred rats (n = 58) three outcomes were identified: rapid extinction (57.3%), slow extinction (32.3%), and failure to extinguish (10.3%) indicating that heterogeneity analogous to that in naturalistic human studies is present in experimental animal studies strengthening their translatability in understanding stress responses in humans.
Journal Article
Diagnostic Performance of Coronary Angiography by 64-Row CT
In an international study, the authors evaluated the diagnostic performance of coronary angiography by means of 64-row multidetector computed tomography (CT). The technique accurately identified obstructive coronary lesions, but the positive and negative predictive values were inadequate for this technology to replace conventional coronary angiography with the use of contrast medium.
In this study, coronary angiography by means of 64-row multidetector computed tomography (CT) accurately identified obstructive coronary lesions, but the positive and negative predictive values were inadequate for this technology to replace conventional coronary angiography.
Coronary artery disease is the leading cause of death in the United States.
1
In symptomatic patients, diagnosis of the presence and severity of coronary artery disease is critical for determining appropriate clinical management.
2
,
3
Indirect evaluation of coronary stenosis, such as through stress testing, has limited diagnostic ability as compared with direct conventional coronary angiography.
4
,
5
Conventional coronary angiography reveals the extent, location, and severity of coronary obstructive lesions, which are potent predictors of outcome,
2
,
3
,
6
,
7
and identifies high-risk patients who may benefit from revascularization.
3
,
6
,
8
–
11
Thus, invasive coronary angiography, despite the associated risks, remains the . . .
Journal Article
Malaysia & Singapore : top sights, authentic experiences
Lonely Planet Best of Malaysia & Singapore is your passport to Malaysia and Singapore's top sights and most authentic experiences. Enjoy some of Malaysia's best food in charismatic George Town, hunt out giant rafflesia flowers in Sarawak or sing karaoke at the Jonker Walk Night Market, all with your trusted travel companion.
Book
β-Adrenergic Receptors Regulate the Acquisition and Consolidation Phases of Aversive Memory Formation Through Distinct, Temporally Regulated Signaling Pathways
Memory formation requires the temporal coordination of molecular events and cellular processes following a learned event. During Pavlovian threat (fear) conditioning (PTC), sensory and neuromodulatory inputs converge on post-synaptic neurons within the lateral nucleus of the amygdala (LA). By activating an intracellular cascade of signaling molecules, these G-protein-coupled neuromodulatory receptors are capable of recruiting a diverse profile of plasticity-related proteins. Here we report that norepinephrine, through its actions on β-adrenergic receptors (βARs), modulates aversive memory formation following PTC through two molecularly and temporally distinct signaling mechanisms. Specifically, using behavioral pharmacology and biochemistry in adult rats, we determined that βAR activity during, but not after PTC training initiates the activation of two plasticity-related targets: AMPA receptors (AMPARs) for memory acquisition and short-term memory and extracellular regulated kinase (ERK) for consolidating the learned association into a long-term memory. These findings reveal that βAR activity during, but not following PTC sets in motion cascading molecular events for the acquisition (AMPARs) and subsequent consolidation (ERK) of learned associations.
Journal Article