An increase in serotonin [5-hydroxytryptamine (5-HT)] levels in the rat visual cortex is correlated with the developmental decrease in long-term potentiation (LTP), and 5-HT may play an important role in the closure of the critical period by regulating LTP. The effect of 5-HT on the induction of N-methyl-D-aspartate receptor (NMDAR)-dependent and metabotropic glutamate receptor (mGluR)-dependent LTP in visual cortex slices from young rats was investigated. The field potential in layer II/III was recorded by stimulating the underlying layer IV. NMDAR-dependent LTP was induced in slices from 3-week-old rats by theta-burst stimulation (TBS) but not in slices from 5-week-old rats. However, LTP was induced in 5-HT-depleted slices from 5-week-old rats by incubation with para-chloroamphetamine (10 microM, 2 h), a 5-HT-depleting agent. The reinstated LTP in 5-HT-depleted slices was inhibited by the application of D-aminopentanoate, an NMDAR antagonist (50 microM) and 5-HT (10 and 30 microM). In contrast, the induction of mGluR-dependent LTP by weak TBS in disinhibited slices with picrotoxin (1 microM) in the bath was not affected by 5-HT application. The coapplication of 5-HT1A and 5-HT2 receptor agonists inhibited the induction of NMDAR-dependent LTP in 5-HT-depleted slices. 5-HT levels in the visual cortex increased with age. Based on these findings, we conclude that NMDAR-dependent LTP is specifically inhibited by coactivation of 5-HT1A and 5-HT2 receptors with the increase in 5-HT levels in the rat visual cortex at the end of the critical period.
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http://dx.doi.org/10.1016/j.brainres.2006.05.046 | DOI Listing |
Elife
January 2025
Department of Psychology, Queens University, Kingston, Canada.
Movie-watching is a central aspect of our lives and an important paradigm for understanding the brain mechanisms behind cognition as it occurs in daily life. Contemporary views of ongoing thought argue that the ability to make sense of events in the 'here and now' depend on the neural processing of incoming sensory information by auditory and visual cortex, which are kept in check by systems in association cortex. However, we currently lack an understanding of how patterns of ongoing thoughts map onto the different brain systems when we watch a film, partly because methods of sampling experience disrupt the dynamics of brain activity and the experience of movie-watching.
View Article and Find Full Text PDFZhong Nan Da Xue Xue Bao Yi Xue Ban
August 2024
Department of Orthopedics, Third Xiangya Hospital, Central South University, Changsha 410013, China.
Objectives: Primary frozen shoulder is a shoulder joint disease that severely impacts the quality of life of patients, and intra-articular injection is a common treatment method. This study aims to evaluate and compare the therapeutic effects of sodium hyaluronate (SH), corticosteroids (CS), and autologous platelet-rich plasma (PRP) in the treatment primary frozen shoulder.
Methods: A total of 117 patients diagnosed with primary frozen shoulder and treated with a single injection of SH, CS, or PRP into the glenohumeral joint under ultrasound guidance at the Third Xiangya Hospital of Central South University from January 1, 2020, to December 31, 2022, were included in the study.
Cell Genom
January 2025
Department of Integrative Biology, The University of Texas at Austin, Austin, TX, USA; Department of Statistics and Data Science, The University of Texas at Austin, Austin, TX, USA. Electronic address:
Humans exhibit distinct characteristics compared to our primate and ancient hominin ancestors. To investigate genomic bursts in the evolution of these traits, we use two complementary approaches to examine enrichment among genome-wide association study loci spanning diseases and AI-based image-derived brain, heart, and skeletal tissue phenotypes with genomic regions reflecting four evolutionary divergence points. These regions cover epigenetic differences among humans and rhesus macaques, human accelerated regions (HARs), ancient selective sweeps, and Neanderthal-introgressed alleles.
View Article and Find Full Text PDFJ Neural Eng
January 2025
Department of Physiology and Department of Electrical and Computer System Engineering, Monash University - Clayton Campus, Wellington Rd, Melbourne, Victoria, 3800, AUSTRALIA.
Development of cortical visual prostheses requires optimization of evoked responses to electrical stimulation to reduce charge requirements and improve safety, efficiency, and efficacy. One promising approach is timing stimulation to the local field potential (LFP), where action potentials have been found to occur preferentially at specific phases. To assess the relationship between electrical stimulation and the phase of the LFP, we recorded action potentials from primary (V1) and secondary (V2) visual cortex in marmosets while delivering single-pulse electrical microstimulation at different phases of the local field potential.
View Article and Find Full Text PDFElife
January 2025
Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Harvard Medical School, Massachusetts General Hospital, Charlestown, United States.
High-resolution awake mouse functional magnetic resonance imaging (fMRI) remains challenging despite extensive efforts to address motion-induced artifacts and stress. This study introduces an implantable radio frequency (RF) surface coil design that minimizes image distortion caused by the air/tissue interface of mouse brains while simultaneously serving as a headpost for fixation during scanning. Furthermore, this study provides a thorough acclimation method used to accustom animals to the MRI environment minimizing motion-induced artifacts.
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