Interaction between hippocampal and striatal systems predicts subsequent consolidation of motor sequence memory.

The development of fast and reproducible motor behavior is a crucial human capacity. The aim of the present study was to address the relationship between the implementation of consistent behavior during initial training on a sequential motor task (the Finger Tapping Task) and subsequent sleep-dependent motor sequence memory consolidation, using functional magnetic resonance imaging (fMRI) and total sleep deprivation protocol. Our behavioral results indicated significant offline gains in performance speed after sleep whereas performance was only stabilized, but not enhanced, after sleep deprivation. At the cerebral level, we previously showed that responses in the caudate nucleus increase, in parallel to a decrease in its functional connectivity with frontal areas, as performance became more consistent. Here, the strength of the competitive interaction, assessed through functional connectivity analyses, between the caudate nucleus and hippocampo-frontal areas during initial training, predicted delayed gains in performance at retest in sleepers but not in sleep-deprived subjects. Moreover, during retest, responses increased in the hippocampus and medial prefrontal cortex in sleepers whereas in sleep-deprived subjects, responses increased in the putamen and cingulate cortex. Our results suggest that the strength of the competitive interplay between the striatum and the hippocampus, participating in the implementation of consistent motor behavior during initial training, conditions subsequent motor sequence memory consolidation. The latter process appears to be supported by a reorganisation of cerebral activity in hippocampo-neocortical networks after sleep

Perfil das intoxicações na infância atendidas pelo Centro de Informação Toxicológica do Rio Grande do Sul (CIT/RS), Brasil Caseload of poisoning among children treated by the Rio Grande do Sul State Toxicology Information Center (CIT/RS), Brazil

Estudo transversal descritivo analítico para estabelecer perfil das intoxicações em crianças de 0 a 4 anos, registradas no Centro de Informação Toxicológica do Rio Grande do Sul (CIT/RS), Porto Alegre, Brasil, 2003. Selecionados 1.311 casos, extraíram-se dados de crianças que sofreram intoxicação acidental individual dentro de suas residências. Em uma amostra do tipo aleatória sistemática de 286 pacientes, foram realizadas 21 entrevistas com responsáveis legais das crianças, utilizando-se instrumento estruturado. O perfil da intoxicação apresentou faixa etária de um ano; gênero masculino; via de exposição oral; agente tóxico localizado no chão da sala de estar ou no quarto; altura do móvel inferior a 30cm; horário da intoxicação entre 18h01-22h; tempo entre o acidente e a busca por uma conduta médica menor que 30 minutos; medicamento analgésico como agente tóxico; avaliação da intoxicação como não tóxica, evoluindo para a cura. Os dados indicam características relevantes quanto ao horário da intoxicação e local em que se encontravam os agentes tóxicos. A definição do perfil permite orientar e incrementar campanhas de prevenção de acidentes tóxicos na infância promovidas pelos órgãos públicos de saúde.<br>This was an analytical, descriptive, cross-sectional study to establish the profile of poisonings among children 0 to 4 years of age reported to the Rio Grande do Sul State Toxicology Information Center (CIT/RS) in Porto Alegre, Brazil, 2003. A total of 1,311 cases were selected and data were extracted on children who had suffered individual accidental poisoning inside the home. From a systematic random sample of 286 patients, 21 interviews were held with the children's parents or guardians, using a structured instrument. The typical profile of poisoning featured: < 1 year age bracket; male gender; oral exposure; poisonous agent located on living room or bedroom floor; furniture height < 30cm; time of poisoning from 18:01 to 22:00; time between poisoning and search for emergency medical care less than 30 minutes; analgesics as poisonous agent; medical assessment of purported poisoning as non-toxic, evolving to cure. The data indicate relevant characteristics as to the time of poisoning and place where poisonous agents were located. Definition of a profile helps promote and expand childhood poisoning prevention campaigns by public health agencies