Guilherme Peres Messas

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Because GABA(A) receptors containing alpha2 subunits are highly represented in areas of the brain, such as nucleus accumbens (NAcc), frontal cortex, and amygdala, regions intimately involved in signaling motivation and reward, we hypothesized that manipulations of this receptor subtype would influence processing of rewards. Voltage-clamp recordings from(More)
Genetic factors play a role in the vulnerability to cocaine dependence. The reinforcing properties of cocaine are related to the dopaminergic system, and, in particular, the dopamine receptors have been linked to the reward mechanisms. The present study examines the role of the variants TaqI A of the dopamine D2 receptor gene and BalI of the dopamine D3(More)
Cocaine addiction involves a number of medical, psychological and social problems. Understanding the genetic aetiology of this disorder will be essential for design of effective treatments. Dopamine-beta hydroxylase (DbH) catalyzes the conversion of dopamine to norepinephrine and could, therefore, have an influence on both cocaine action and the basal(More)
OBJECTIVE The search for genetic vulnerability factors in cocaine dependence has focused on the role that neuroplasticity plays in addiction. However, like many other drugs, the ability of an individual to metabolize cocaine can also influence susceptibility to dependence. Butyrylcholinesterase (BChE) metabolizes cocaine, and genetic variants of the BChE(More)
Two fundamentally different approaches among phenomenological psychopathologists can be discerned. One is what we call fixed essentialism, where the pathognomonic element of, say, schizophrenia is conceived of as a single, enduring and intrinsically morbid way of grasping all entities in the world, including self and body. The other, which we call(More)
Epidemiological studies on schizophrenia have showed different age at onset between gender, in which male schizophrenics present symptoms earlier than females. However this gender effect is not observed within familial schizophrenia. The present study investigates the age at onset in 31 RDC-schizophrenics from 13 Brazilian families. No differences in age at(More)
* Universidade de São Paulo – USP (São Paulo, SP, Br). * Faculdade de Ciências Médicas da Santa Casa de São Paulo (São Paulo, SP. Br). Due to growing skepticism about the current psychiatric model, psychopathology has once again aroused interest in the psychiatric field. This article intends to examine the current perspectives of the phenomenological(More)
In this article we examined the heritability of alcohol dependence. A review of family, twin and adoption studies, allowed us to support the thesis of an important genetic component in this dependence. The transmission of this heritability occurs through a biological vulnerability associated to environmental factors, in a model called epigenetic. We also(More)
The article explores the evolution of the Brazilian republic's laws and norms on mental illness during three periods. The first (1890-1910) saw the topic of mental pathology introduced into the State's realm of interest, with the main concern being to recognize and preserve the rights of those displaying such pathologies. During this period, mental(More)
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