Several recent studies have reported that D-cycloserine (DCS), a partial N-methyl-D-aspartate agonist, facilitates extinction of learned fear in rats. Other studies have shown that representation of the unconditioned stimulus (US) can reinstate learned fear after extinction. This study examined whether this reinstatement effect occurs in Sprague-Dawley rats given DCS at the time of extinction. Results showed that saline-treated rats exhibited the reinstatement effect but DCS-treated rats did not (Experiments 1 and 2). This lack of reinstatement in DCS-treated rats was not due to residual effects of DCS on either US or context processing (Experiment 3). Overall, these results (a) raise questions about the mechanisms underlying DCS facilitation of extinction and (b) suggest that DCS might have substantial practical benefit.
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http://dx.doi.org/10.1037/0735-7044.118.3.505 | DOI Listing |
J Theor Biol
January 2025
Technion Israel Institute of Technology, Faculty of Mathematics, Technion City, Haifa, 3200003, Israel. Electronic address:
The competitive exclusion principle in epidemiology implies that when competing strains of a pathogen provide complete protection for each other, the strain with the largest reproduction number outcompetes the other strains and drives them to extinction. The introduction of various trade-off mechanisms may facilitate the coexistence of competing strains, especially when their respective basic reproduction numbers are close so that the competition between the strains is weak. Yet, one may expect that a substantial competitive advantage of one of the strains will eventually outbalance trade-off mechanisms driving less competitive strains to extinction.
View Article and Find Full Text PDFParasitol Int
January 2025
Faculty of Environmental Science, The University of Shiga Prefecture, Shiga, Japan. Electronic address:
Lake Biwa, with its long geological history, has given rise to many endemic species, but only four endemic parasites are known from Lake Biwa and connected water areas. They are considered to have co-evolved with their endemic host species or to have become adapted to the pelagic ecosystem unique to Lake Biwa. The number of parasite species introduced into this water system is rising, facilitated not only by the introduction of new species but also through genetic analyses that have revealed new information about previously known species.
View Article and Find Full Text PDFClin Neuroradiol
January 2025
Neurosciences Research Center (NSRC), Tabriz University of Medical Sciences, Tabriz, Iran.
Background: Hypertension (HTN) is a prevalent cardiovascular condition associated with cognitive impairments, including memory deficits and attention lapses. Understanding the neural mechanisms underlying HTN-related cognitive dysfunction is crucial for optimizing treatment strategies.
Method: A systematic review was conducted to explore the impact of antihypertensive medications on cognition, focusing on memory, attention, and emotion processing using functional magnetic resonance imaging (fMRI).
Sci Rep
January 2025
Department of Neuroscience and Addiction Studies, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, No. 38, Italia Ave., Ghods St, Keshavarz Boulevard, Tehran, Iran.
Substance Use Disorder (SUD) is a medical condition where an individual compulsively misuses drugs or alcohol despite knowing the negative consequences. The anterior cingulate cortex (ACC) has been implicated in various types of SUDs, including nicotine, heroin, and alcohol use disorders. Our research aimed to investigate the effects of deep brain stimulation (DBS) in the ACC as a potential therapeutic approach for morphine use disorder.
View Article and Find Full Text PDFBiol Lett
January 2025
Manaaki Whenua-Landcare Research, Lincoln, Canterbury 7640, New Zealand.
Mycovores (animals that consume fungi) are important for fungal spore dispersal, including ectomycorrhizal (ECM) fungi symbiotic with forest-forming trees. As such, fungi and their symbionts may be impacted by mycovore extinction. New Zealand (NZ) has a diversity of unusual, colourful, endemic sequestrate (truffle-like) fungi, most of which are ECM.
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