PET Neuroimaging Reveals Serotonergic and Metabolic Dysfunctions in the Hippocampal Electrical Kindling Model of Epileptogenesis.

Neuroscience

Unidad de Cartografía Cerebral, Instituto Pluridisciplinar, Universidad Complutense de Madrid, Paseo Juan XXIII, 1, 28040, Madrid, Spain; Curium Pharma Spain (formerly Instituto Tecnológico PET), C/ Manuel Bartolomé Cossío, 10, 28040, Madrid, Spain; Departamento de Fisiología, Facultad de Medicina, Universidad Complutense de Madrid, Plaza Ramón y Cajal s/n, 28040, Madrid, Spain.

Published: June 2019

Glucose metabolism and serotonergic neurotransmission have been reported to play an important role in epileptogenesis. We therefore aimed to use neuroimaging to evaluate potential alterations in serotonin 5-HT receptor and glucose metabolism during epileptogenesis in the rat electrical kindling model. To achieve this goal, we performed positron emission tomography (PET) imaging in a rat epileptogenesis model triggered by electrical stimulation of the hippocampus using 2-deoxy-2-[F]fluoro-D-glucose (F-FDG), a radiolabeled analog of glucose, and 2'-methoxyphenyl-(N-2'-pyridinyl)-p-F-fluoro-benzamidoethylpiperazine (F-MPPF), a radiolabeled 5-HT receptor ligand, to evaluate brain metabolism and 5-HT receptor functionality. Since the 5-HT receptor is also highly expressed in astrocytes, glial fibrillary acidic protein (GFAP) immunofluorescence was performed to detect astrogliosis arising from the kindling procedure once the study was finalized. Lastly, in vitroF-MPPF autoradiography was performed to evaluate changes in 5HT receptor expression. F-FDG PET showed reduction of glucose uptake in cortical structures, whereas F-MPPF PET revealed an enhancement of tracer binding potential (BP) in key areas rich in 5-HT receptor involved in epilepsy, including septum, hippocampus and entorhinal cortex of kindled animals compared to controls. However, in vitro 5-HT receptor autoradiography showed no changes in densitometric signal in any brain region, suggesting that the augmentation in BP found by PET could be caused by reduction of synaptic serotonin. Importantly, astroglial activation was detected in the hippocampus of kindled rats. Overall, electrical kindling induced hypometabolism, astrogliosis and serotonergic alterations in epilepsy-related regions. Furthermore, the present findings point to 5-HT receptor as a valuable epileptogenesis biomarker candidate and a potential therapeutic target.

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.neuroscience.2019.04.028DOI Listing

Publication Analysis

Top Keywords

5-ht receptor
28
electrical kindling
12
kindling model
8
glucose metabolism
8
receptor
8
5-ht
7
pet
5
epileptogenesis
5
pet neuroimaging
4
neuroimaging reveals
4

Similar Publications

Molecular Mechanisms of Nicergoline from Ergot Fungus in Blocking Human 5-HT3A Receptor.

J Microbiol Biotechnol

November 2024

Department of Biotechnology and Department of Integrative Food, Bioscience and Biotechnology (BK21 FOUR), Chonnam National University, Gwangju 61186, Republic of Korea.

This study investigates the modulatory effects of nicergoline, a major bioactive compound derived from ergot fungus, on the 5-hydroxytryptamine 3A (5-HT3A) receptor. Utilizing a two-electrode voltage-clamp technique, we evaluated the impact of nicergoline on the 5-HT-induced inward current (I) in 5-HT3A receptors. Our findings reveal that nicergoline inhibits I in a reversible and concentration-dependent manner.

View Article and Find Full Text PDF

Depression is one of the most common non-motor symptoms in Parkinson's disease (PD) and the hyperactivity of the lateral habenula (LHb) may contribute to depression. The present study was performed to investigate the effects and mechanisms of group I metabotropic glutamate receptors (mGluRs) in the LHb on PD-related depressive-like behaviors. Unilateral 6-hydroxydopamine lesions of the substantia nigra pars compacta (SNc) were used to establish the PD rat model.

View Article and Find Full Text PDF

Chronotropic effects of milrinone in a guinea pig ex vivo model: a pilot study to screen for new mechanisms of action.

J Cardiovasc Pharmacol

January 2025

Division of Clinical Physiology, Department of Cardiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.

Positive inotropic responses upon administration of milrinone, an inhibitor of the phosphodiesterase enzyme (PDE), involve a well-pronounced positive chronotropic effect. Here we tested whether milrinone evokes this chronotropic response solely by PDE inhibition or by a concerted action that involve additional pharmacological targets. Milrinone stimulated increases in heart rate were studied in right atrial preparations of guinea pig in the presence or absence of inhibitors of putative ancillary molecular pathways or ion channels: i.

View Article and Find Full Text PDF

The lipocalin saga: Insights into its role in cancer-associated cachexia.

Biochim Biophys Acta Mol Basis Dis

January 2025

National Forensic Sciences University, Gandhinagar 382007, Gujarat, India. Electronic address:

Cancer-associated cachexia (CAC) is a debilitating condition, observed in patients with advanced stages of cancer. It is marked by ongoing weight loss, weakness, and nutritional impairment. Lower tolerance of chemotherapeutic agents and radiation therapy makes it difficult to treat CAC.

View Article and Find Full Text PDF

The hormone and neurotransmitter serotonin regulates numerous physiological functions within the central nervous system and in the periphery upon binding to specific receptors. In the periphery, the serotonin receptor 7 (5-HT7R) is expressed on different immune cells including monocytes and macrophages. To investigate the impact of 5-HT7R-mediated signaling on macrophage properties, we used human THP-1 cells and differentiated them into pro-inflammatory M1- and anti-inflammatory M2-like macrophages.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!