The neonatal hippocampus lesion thought to model schizophrenia should show the same modifications in behavioural tests as other models, especially pharmacological models, namely decreased latent inhibition, blocking and overshadowing. The present study is set out to evaluate overshadowing in order to complement our previous studies, which had tested latent inhibition. "Overshadowing" refers to the decreased conditioning that occurs when the to-be-conditioned stimulus is combined with another stimulus at the conditioning stage. We used the same two Pavlovian conditioning paradigms as in our previous works, namely conditioned taste aversion (CTA) and conditioned emotional response (CER). A sweet taste overshadowed a salty conditioned stimulus, and a tone overshadowed a flashing light. Totally different stimuli were used to counter possible sensory biases. The protocols were validated with two groups of Sprague Dawley rats. The same two protocols were then applied to a cohort of rats whose ventral hippocampus had been destroyed when they were 7days old. Only rats with extended ventral hippocampus lesions were included. The overall effect of Pavlovian conditioning was attenuated, significantly so in the conditioned emotional response paradigm, but overshadowing appeared not to be modified in either the conditioned emotional response or the conditioned taste aversion paradigm.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.bbr.2008.06.014 | DOI Listing |
Sheng Li Xue Bao
December 2024
State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China.
At present, the problem of drug addiction treatment mainly lies in the high relapse rate of drug addicts. Addictive drugs will bring users a strong sense of euphoria and promote drug seeking. Once the drug is withdrawn, there will be withdrawal symptoms such as strong negative emotions and uncomfortable physical reactions.
View Article and Find Full Text PDFPsychophysiology
January 2025
Research Group Health Psychology, KU Leuven, Leuven, Belgium.
Transcutaneous auricular vagus nerve stimulation (taVNS) has been tested as a strategy to facilitate fear extinction learning based on the hypothesis that taVNS increases central noradrenergic activity. Four studies out of six found taVNS to enhance extinction learning especially at the beginning of extinction. Facilitatory effects of taVNS were mainly observed in US expectancy, less in fear-potentiated startle (FPS), and not in the skin conductance response (SCR).
View Article and Find Full Text PDFCells
December 2024
Oujiang Laboratory (Zhejiang Lab for Regenerative Medicine, Vision, and Brain Health), Institute of Mental Health and Drug Discovery, School of Mental Health, Wenzhou Medical University, Ouhai District, Wenzhou 325000, China.
Background: glucocorticoids may play an important role in the formation of fear memory, which is relevant to the neurobiology of post-traumatic stress disorder (PTSD). In our previous study, we showed the glucocorticoid receptor (GR) forms a protein complex with FKBP51, which prevents translocation of GR into the nucleus to affect gene expression; this complex is elevated in PTSD patients and by fear-conditioned learning in mice, and disrupting this complex blocks the storage and retrieval of fear-conditioned memories. The timing of release of glucocorticoid relative to the formation of a traumatic memory could be important in this process, and remains poorly understood.
View Article and Find Full Text PDFJ Eval Clin Pract
February 2025
California State University Monterey Bay, Seaside, California, USA.
Rationale: Obesity is an increasing medical issue not responding well to behavioural treatments beyond their initial weeks/months.
Aims And Objectives: Before suggesting surgical or pharmacological interventions, medical professionals might consider referrals to cost-effective, community-based behavioural treatments if stronger theoretical/empirical bases were demonstrated. Thus, evaluation of such is warranted.
Sci Rep
January 2025
Department of Molecular, Cellular, and Biomedical Sciences, College of Life Sciences and Agriculture, University of New Hampshire, Durham, NH, 03824, USA.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!