Age-related declines in prefrontal functions and age-related declines in prefrontal serotonin (5-HT) are documented. The effect of 5-HT on prefrontal cortex (PFC) is also documented; however, no one has examined the effect of experimental 5-HT modulation on PFC in healthy older adults. We investigated the effect of 5-HT on brain functioning in 10 women over 55 (mean=63.0+/-5.3 years) during cognitive interference inhibition (Simon task) using fMRI and acute tryptophan depletion (ATD). ATD did not affect task performance; it did affect brain function. During sham/no depletion, participants activated brain regions associated with the Simon (e.g., left inferior PFC). During ATD, there was no prefrontal but alternative posterior brain activation. ATD relative to sham reduced activity in left inferior PFC, anterior cingulate and basal ganglia but increased activity within neocerebellum and parietal lobe. In older adults, ATD modulates task-relevant brain activation for cognitive interference inhibition and is associated with an anterior-to-posterior activation shift. Maintaining successful Simon performance during ATD is achieved by increasing cerebellar and parietal contributions to compensate for decreased fronto-cingulo-striatal involvement.
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http://dx.doi.org/10.1016/j.neurobiolaging.2007.09.013 | DOI Listing |
Int J Mol Sci
December 2024
Neuroscience Research Institute, Gachon University, Incheon 21565, Republic of Korea.
To elucidate the potential roles of presynaptic and postsynaptic serotonergic activity in impulsivity traits, we investigated the relationship between self-reported impulsiveness and serotonin transporter (5-HTT) and 5-HT2A receptors in healthy individuals. In this study, 26 participants completed 3-Tesla magnetic resonance imaging and positron emission tomography with [C]DASB and [C]MDL100907. To quantify 5-HTT and 5-HT2A receptor availability, the binding potential (BP) of [C]DASB and [C]MDL100907 was derived using the simplified reference tissue model with cerebellar gray matter as the reference region.
View Article and Find Full Text PDFBrain Res Bull
January 2025
Sino-UK International Joint Laboratory of Brain Injury in Henan Province, Henan International Joint Laboratory of Neuromodulation, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, China. Electronic address:
Objective: This study aimed to investigate the effect of aminooxyacetic acid (AOAA) on cognitive function, particularly learning and memory, in a rat model of chronic alcoholism. Additionally, the study explored changes in cystathionine β-synthase (CBS), hydrogen sulfide (H₂S), and serotonin (5-HT) levels in the prefrontal cortex to understand the potential neurochemical mechanisms involved.
Methods: Sixty-four male SD rats were randomly divided into four groups, with 16 rats in each: Con, Con + AOAA, Model, and Model + AOAA.
Microorganisms
December 2024
Department of Biotechnology and Environmental Microbiology, Autonomous Metropolitan University-Lerma, Hidalgo Pte. 46, Lerma 52006, State of Mexico, Mexico.
Unlabelled: Dysfunction in the prefrontal cortex can lead to cognitive inflexibility due to multifactorial causes as included cardiometabolic disorders, stress, inadequate diets, as well as an imbalance of the gut-brain axis microbiota. However, these risk factors have not been evaluated jointly. The purpose of this study was to evaluate the effect of physical stress (MS: Male Stress and FS: Female Stress) and high-fat diet (MD: Male Diet and FD: Female Diet) supplementation on the gut microbiota and cognitive flexibility.
View Article and Find Full Text PDFFood Funct
January 2025
Hubei Provincial Engineering and Technology Research Center for Food Ingredients, Hubei University of Arts and Science, Xiangyang, Hubei, PR China.
The gut microbiome has emerged as a growing focus of research and public health interest, leading to the frequent exploration of probiotic dietary supplements as potential treatments for various disorders, such as anxiety and depression. In the present report, changes in inflammation and microbiome composition were assessed in model mice exhibiting depressive-like behaviors that were exposed to the probiotic HBUAS52074. It was found that HBUAS52074 alleviated the severity of depressive-like behaviors while increasing serum 5-HT concentrations.
View Article and Find Full Text PDFBehav Pharmacol
December 2024
Neurolixis SAS, Castres, France.
Ketamine displays efficacious rapid-acting antidepressant (RAAD) activity in the rat chronic mild stress (CMS) model. It rapidly reverses anhedonia (CMS-induced sucrose consumption deficit) and attenuates working memory deficit (novel object recognition: NOR) following both systemic (intraperitoneal, i.p.
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