Context discrimination and time course studies of contextual fear conditioning revealed strain differences between C57BL/6J (B6) and DBA/2J (D2) mice. Both strains discriminated contexts, but D2 mice exhibited less freezing in a shock-paired context. The strains did not differ immediately, or at 1 and 3 hr after contextual fear conditioning training. D2 mice showed less freezing at 15 min, 30 min, and 24 hr after training. B6 mice exhibited exaggerated generalized freezing and poor discrimination between the context and altered context 7-30 days after training. The acoustic startle response in B6 mice was also enhanced at 14 days after training. D2 mice did not show this pattern of generalized freezing. B6, but not D2, mice retained contextual memories for at least 60 days.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1037//0735-7044.116.6.947 | DOI Listing |
Elife
January 2025
Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, United States.
The central amygdala (CeA) has emerged as an important brain region for regulating both negative (fear and anxiety) and positive (reward) affective behaviors. The CeA has been proposed to encode affective information in the form of valence (whether the stimulus is good or bad) or salience (how significant is the stimulus), but the extent to which these two types of stimulus representation occur in the CeA is not known. Here, we used single cell calcium imaging in mice during appetitive and aversive conditioning and found that majority of CeA neurons (~65%) encode the valence of the unconditioned stimulus (US) with a smaller subset of cells (~15%) encoding the salience of the US.
View Article and Find Full Text PDFBehav Brain Res
January 2025
Division of Biotechnology, School of Life Sciences, Manipal Academy of Higher Education, Manipal- 576104, India.
Whilst the world sees the tremendous growth of mobile phone technology, radiofrequency electromagnetic radiation (RF-EMR) induced possible health effects have emerged as a topic of recent day debate. The current study is designed to test the hypothesis that chronic 900MHz radiation exposure would potentially dysregulate the stress response system (HPA axis) in vivo, via, its non-thermal mechanisms, leading to alterations in the microarchitecture of the adrenal gland, vulnerable brain regions such as the hippocampus which may results in altered behaviours in rats. Male albino Wistar rats aged four weeks, weighing 50-60g were subjected to 900MHz radiation from a cellphone for four weeks at a rate of one hour per day.
View Article and Find Full Text PDFExp Neurol
January 2025
School of Public Health, Nanjing Medical University, Nanjing 211166, China. Electronic address:
Postoperative cognitive dysfunction (POCD) is a prevalent clinical issue following anesthesia and surgery. The onset of POCD, which is closely linked to circadian rhythm disturbance in previous studies, yet the underlying mechanism remains elusive. There is increasing evidence showed that mitochondrial architecture is coordinated by the circadian clock which DRP1 playing a crucial role.
View Article and Find Full Text PDFNeurosci Biobehav Rev
January 2025
Department of Psychology, University of Turin, Turin, Italy; Department of Medical and Clinical Psychology, Tilburg University, Netherlands; Centro Linceo Interdisciplinare "Beniamino Segre", Accademia Nazionale dei Lincei, Roma, Italy. Electronic address:
Fear responses to novel stimuli can be learned directly, through personal experiences (Fear Conditioning, FC), or indirectly, by observing conspecific reactions to a stimulus (Social Fear Learning, SFL). Although substantial knowledge exists about FC and SFL in humans and other species, they are typically conceived as mechanisms that engage separate neural networks and operate at different levels of complexity. Here, we propose a broader framework that links these two fear learning modes by supporting the view that social signals may act as unconditioned stimuli during SFL.
View Article and Find Full Text PDFCell Rep
January 2025
Department of Cell Biology and Anatomy, LSUHSC, New Orleans, LA 70112, USA; Southeast Louisiana VA Healthcare System, New Orleans, LA 70119, USA. Electronic address:
Stress can alter behavior and contributes to psychiatric disorders by regulating the expression of the GluA2 AMPA receptor subunit. We have previously shown in mice that exposure to predator odor stress elevates GluA2 transcription in cerebellar molecular layer interneurons (MLIs), and MLI activity is required for fear memory consolidation. Here, we identified the critical involvement of adenylyl cyclase 5, in both the stress-induced increase in GluA2 in MLIs and the enhancement of fear memory.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!