1,721,179 research outputs found
Correlati anatomo-funzionali della depressione e della risposta ai farmaci serotoninergici
No full textRiassunto Gli studi sulla neurobiologia della depressione sono in minoranza rispetto a quelli relativi ad altri disturbi mentali come
la schizofrenia, e hanno finora messo in evidenza solo alcuni degli aspetti che sembrano essere alla base della regolazione del
tono dell'umore e delle sue disfunzioni. In questa rassegna prenderemo in considerazione le ricerche più informative in relazione a
queste tematiche, cercando evidenziare i collegamenti tra i risultati ottenuti. Prenderemo anche in considerazione gli aspetti relativi
al trattamento con farmaci inibitori del reuptake della serotonina, cercando di comprendere come la loro azione possa influenzare
la funzionalità delle reti neuronali che sottendono alla regolazione del tono dell'umore
The genetics of schizophrenia
No full textResearch on the genetic factors conferring risk for
schizophrenia has not provided definitive answers. In the
present review, we will discuss potential clinical and genetic
limitations intrinsic to the strategies using a diagnostic phenotype.
Among clinical factors, uncertainty of the phenotype
is certainly a major limitation. Genetic problems include locus
heterogeneity and the complex genetic architecture of
the phenotype. Given these limiting factors, we will also discuss
another hypothesis-driven strategy to uncover genetic
risk: the use of quantitative measures (intermediate phenotypes)
within more specific neurobiological mechanisms. As
a clear example of all these issues and because of the longstanding
involvement in the pathophysiology of this disorder,
we will review the association of the gene for dopamine
D2 receptors (DRD2) with diagnosis of schizophrenia and
with specific working memory behavioral and brain activity
phenotypes. We conclude by suggesting that hypothesis-free
and hypothesis-driven are not mutually exclusive strategies
and may provide information at different levels that are both
useful and equally valid about genetic risk for a complex
diagnostic entity like schizophrenia and for a complex phenotype
like psychosis
Spettroscopia Protonica con Risonanza Magnetica nella schizofrenia: considerazioni cliniche
No full textLa Spettroscopia Protonica con Risonanza Magnetica (l H-MRS) è diventata un
importante strumento per lo studio in vivo di alcuni aspetti biochimici dei disturbi del
cervello. Nell'u1tima decade questa tecnica è stata utilizzata per l'investigazione in
vivo della patofisiologia dei disturbi psichiatrici. Questo articolo descrive i principi su
cui si basa la MRS e gli studi effettuati nella schizofrenia con questa metodologia, con
particolare riferimento a que11i che hanno chiarito alcuni elementi della relazione fra
gli aspetti biochimici e que11i clinici. I dati sembrano coinvolgere nella patofisiologia
della schizofrenia fondamentalmente due strutture: l'ippocampo, soprattutto per quanto
riguarda una potenziale suscettibilità, e la corteccia prefrontale dorsolaterale, che
sembra invece essere la regione anatomica effettrice della disregolazione del sistema
dopaminergico, dei deficit di working memOl)' e dei sintomi negativi. Coerentemente a
ciò, gli antipsicotici, ed in particolare que11idi seconda generazione, sembrano modificare
i segnali di MRS particolarmente nella corteccia prefrontale
The use of functional imaging to evaluate the neurobiology of putative schizophrenia susceptibility genes
No full textNoninvasive functional neuroimaging techniques are leading the way to greater knowledge about the neurobiology of the
central nervous system and of brain disorders. Combination of this knowledge with information from ascertainment of
genetic variation is also allowing evaluation of individual variability in brain function, so-called "imaging genetics". This
research field may be particularly relevant for schizophrenia, since earlier genetic linkage and association studies using the
clinical phenotype have produced mixed results. Brain imaging phenotypes may help to fill the gap between genes and
phenotypic expression in this disorder. This review will consider the evidence showing how genetic variants putatively
involved in the pathophysiology of schizophrenia - namely catechol-O-methyltransferase, glutamate metabotrophic
receptor 3, Disrupted-in-Schizophrenia-l, brain-derived neurotrophic factor and dysbindin - impact on brain function in
healthy subjects and in schizophrenia patients. Furthermore, we will focus on how individual genetic variability potentially
modulates the response to antipsychotic treatment in this disorder. The studies reviewed herein suggest that utilisation of
brain imaging phenotypes is useful for association studies to reveal the genes potentially involved in explaining risk for
schizophrenia as well as for deeper understanding of the pathophysiology and of the individuality of response to
pharmacological treatment in this disorder
Imaging genomics and response to treatment with antipsychotics in schizophrenia
No full textRecent important advancements in genomic research have opened the way to new strategies for public health management. One of these questions pertains to how individual genetic variation may be associated with individual variability in response to drug treatment. The field of pharmacogenetics may have a profound impact on treatment of complex psychiatric disorders like schizophrenia. However, pharmacogenetic studies in schizophrenia have produced conflicting results. The first studies examined potential associations between clinical response and drug receptor genes. Subsequent studies have tried to use more objective phenotypes still in association with drug receptor genes. More recently, other studies have sought the association between putative causative or modifier genes and intermediate phenotypes. Thus, conflicting results may be at least in part explained by variability and choice of the phenotype, by choice of candidate genes, or by the relatively little knowledge about the neurobiology of this disorder. We propose that choosing intermediate phenotypes that allow in vivo measurement of specific neuronal functions may be of great help in reducing several of the potential confounds intrinsic to clinical measurements. Functional neuroimaging is ideally suited to address several of these potential confounds, and it may represent a powerful strategy to investigate the relationship between behavior, brain function, genes, and individual variability in the response to treatment with antipsychotic drugs in schizophrenia. Preliminary evidence with potential susceptilibity genes such as COMT, DISC1, and GRM3 support these assumptions. © The American Society for Experimental NeuroTherapeutics, Inc
La valutazione intermedia dei PSR in Italia: modelli a confronto
No full textLa valutazione intermedia dei PSR in Italia: modelli a confront
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