TRH attenuates scopolamine-induced memory impairment in humans

The brain tripeptide thyrotropin-releasing hormone (TRH) has been demonstrated to facilitate cholinergic neurotransmission. To test its interaction with the cholinergic system in humans, high-dose TRH (0.5 mg/kg) or placebo was administered intravenously (IV) to normal controls pretreated with scopolamine (0.5–0.75 mg IV), a centrally active muscarinic antagonist, which has been used to model aspects of the memory impairment of normal aging and of dementia. Compared to placebo, TRH markedly attenuated scopolamine-induced impairment of some measures of memory, most notably on a selective reminding task. This cognitive study is the first in humans to suggest a neuromodulatory effect of a peptide on the cholinergic system, and suggests a facilitatory role for TRH in human memory processes.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46332/1/213_2005_Article_BF02245795.pd

Relationship Among a Supernova, a Transition of Polarity of the Geomagnetic Field and the Pliocene-Pleistocene Boundary

After the Middle Miocene, two important climatic changes took place, consisting mainly of cooling in both hemispheres. One occurred between 7.0 and 5.4 Ma and another at the end of the Pliocene, which marked the beginning of the Pleistocene in approximately 2.58 Ma. The proposal of thispresentation is to analyze diverse forcings of these climatic changes, such as the influence of the joint occurrence of reversions of the geomagnetic field andexplosions of a supernova. These events occurred coincidentally with thecooling of Earth. Also, biological changes in those time intervals are analyzed,especially the evolution of the Hominins since the oldest hominin fossils. Thecharacteristics of the Galactic Cosmic Rays, its influence on the climate and its potential mutogenetic effect were taken into account.Briefly, according to our analysis, it seems to be evident that together withother factors, the joint occurrence of the explosion of a supernova at less than100 pc from the Earth and the weakening and/or reversion of the GeomagneticField was an important factor that promoted these two climatic and ecosystemchanges.Fil: Compagnucci, Rosa Hilda. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Orgeira, Maria Julia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires; ArgentinaFil: Sinito, Ana Maria. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cappellotto, Luiggina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires; ArgentinaFil: Plastani, María Sofía. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; Argentin