There are conflicting reports on the influence of thyrotropin-releasing hormone (TRH) on the process of learning. We decided to study this problem using the paradigm of classical eyeblink conditioning as the animal model of learning processes. During the extinction training TRH in its natural form of pG1uTRH was applied into the rabbit hippocampus through a chronically implanted microdialysis probe. A Glu(1)TRH, analog with less biological potency than TRH as the control of specificity for TRH and a 0.9% NaCl solution as the control for both substances were applied by the same way as pGluTRH. We found that pGluTRH extended the process of extinction and enhanced the further acquisition of the reflex. The analog of TRH, Glu(1)TRH, was ineffective. Finally, it may be stated that TRH acting in the hippocampus prolonged process of forgetting and improved succeeding learning. The effect was specific and long lasting.
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http://dx.doi.org/10.55782/ane-2007-1632 | DOI Listing |
Cureus
September 2024
Physiology, All India Institute of Medical Sciences, Jodhpur, Jodhpur, IND.
Dr. Roger Guillemin was a French physiologist who won the Nobel Prize in 1977. His pioneering research and fierce competition led to the isolation and identification of hypothalamic hormones, including thyrotropin-releasing factor (TRF), luteinizing hormone-releasing factor (LRF), and somatostatin.
View Article and Find Full Text PDFGen Comp Endocrinol
November 2024
Centro de Investigaciones Biológicas del Noroeste (CIBNOR), Calle Instituto Politécnico Nacional 195, La Paz, B.C.S. 23096, Mexico. Electronic address:
We analyzed the expression of genes involved in the hypothalamic-pituitary-thyroid axis (HPT-axis) in the longfin yellowtail Seriola rivoliana early larva, including temperature effects (22, 26 and 28 °C) and days of development (day one, day two, and day six after hatching). We aimed to determine if egg and larval incubation at different temperatures could disrupt this critical endocrine axis, which, in an aquaculture context, it could provoke mortality during early metamorphosis. There was a significant interaction between temperature and developmental timing on the relative expression of thyrotropin releasing hormone (trh).
View Article and Find Full Text PDFFront Endocrinol (Lausanne)
September 2024
State Key Laboratory of Space Medicine, China Astronaut Research and Training Center, Beijing, China.
Toxicology
November 2024
Departamento de Neuromorfología Funcional, Dirección de Investigaciones en Neurociencias, Instituto Nacional de Psiquiatría Ramón de la Fuente Muñiz, Calz. México Xochimilco No. 101, Col. San Lorenzo Huipulco, México, D.F. C.P. 14370, México.
Polychlorinated biphenyls (PCBs) are industrial pollutants that act as endocrine disruptors and alter thyroid function. However, it is still unclear whether PCBs can affect hypothalamic thyrotropin releasing hormone (Trh) mRNA expression through TH signaling disruption. As salt-loading dehydration induces tertiary hypothyroidism in the hypothalamic parvocellular paraventricular nuclei (paPVN), and perinatal exposure to Aroclor 1254 (A1254) disrupts the hydric balance in rats, we hypothesized that TRH synthesis could be altered during dehydration in TRH neurons that control the hypothalamic-pituitary-thyroid (HPT) axis activity in rats perinatally exposed to A1254.
View Article and Find Full Text PDFColloids Surf B Biointerfaces
November 2024
Key Lab of Colloid and Interface Chemistry, Shandong University, Jinan, Shandong 250100, PR China. Electronic address:
Transdermal drug delivery (TDD) has attracted widespread attention because of the advantage of its non-invasive nature, easy self-administration, and low side effects. The key to this pathway of drug delivery is how to overcome the barrier of the lipid matrix in the stratum corneum (SC). In this work, molecular dynamics (MD) were employed to investigate the adsorption of thyrotropin-releasing hormone (TRH) on the SC, and the effects of three different chemical permeation enhancers (ethanol (ETOH), carveol (CAV), and borneol (BOR)) on the SC were analyzed.
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