Germán Andrés Vargas Torres

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Ketamine exerts powerful anesthetic, psychotic, and antidepressant effects in both healthy volunteers and clinically depressed patients. Although ketamine targets particular glutamate receptors, there is a dearth of evidence for additional, alternative molecular substrates for the behavioral actions of this N-methyl-D-aspartate (NMDA) receptor antagonist(More)
Mutations within the amino acid sequence of Parkin, the encoded protein of the parkin gene, appear to trigger the degeneration of dopaminergic neurons in the substantia nigra. Here, the presence and anatomical distribution of Parkin within the rat was examined. Immunoblot analysis of tissue homogenates showed two major bands at 50 and 44kDa. Within the(More)
Cytokines such as interleukin-1 beta (IL-1 beta) alter the activity of the hypothalamic-pituitary-adrenal (HPA) and hypothalamic-pituitary-gonadal (HPG) axes in the rat. However, the brain sites at which IL-1 beta exerts these effects have not been well identified. The present study sought to identify some of these sites, using c-fos protein expression as(More)
Aging societies face an increasing prevalence of neurodegenerative disorders for which no cure exists. The paucity of relevant animal models that faithfully reproduce clinical and pathogenic features of neurodegenerative diseases is a major cause for the lack of effective therapies. Clinically distinct disorders, such as Alzheimer's and Parkinson's disease,(More)
A model of schizophrenia, the chakragati (ckr) mouse was serendipitously created as a result of a transgenic insertional mutation. The apparent loss-of-function of an endogenous gene produced mice that, when homozygous, displayed an abnormal circling behavior phenotype. To determine whether this phenotype could be corrected by atypical antipsychotics, we(More)
The use of Drosophila as a model to study the behavioral consequences of stimulant drugs was analyzed in an active preparation of decapitated Drosophila. Application of cocaine and cocaethylene to discrete nerve cord cells regulating motor programs of behavior produced striking patterns of behavioral activity in a concentration-related manner. In general,(More)
To assess the possible involvement of NMDA receptors in mediating the expression of striatal c-fos by cocaine injection, we investigated the effects of the noncompetitive NMDA receptor antagonists, ketamine and (+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine hydrogen maleate (MK-801), as well as the competitive NMDA receptor antagonist,(More)
Sirtuins function with other biogenic molecules to promote adaptation to caloric restriction in a broad spectrum of eukaryotic species. Sirtuin pathways also converge in the mammalian brain where they appear to protect neurons from nutrient stress. However, few anatomical studies on sirtuins (e.g., SIRT1) are available, particularly those detailing the(More)
Cocaethylene is a psychoactive metabolite formed during the combined consumption of cocaine and ethanol. As this metabolite has many properties in common with cocaine, it is conceivable that cocaethylene administration may induce the activity of nuclear transcription factors that regulate the expression of late-response genes. Therefore, the temporal(More)
1. Ethanol and cocaine are drugs of abuse that can produce long-lived changes in behavior, including dependence. 2. A common set of neural pathways appears to mediate the addictive actions of ethanol and cocaine. 3. Many prominent aspects of drug dependence may be the result of alterations in intracellular signals as well as specific patterns of gene(More)