Sleep/wake cycle pattern and its relationship with anxiety in college students. This paper examines the relationship between the sleep/wake cycle and anxiety in medical students. The sleep/wake cycle and anxiety were evaluated in 37 second year medical school students. The volunteers answered a morningness-eveningness questionnaire, Pittsburgh Sleep Quality Index -PSQI and state and trait of anxiety inventory -STAI; all kept a sleep/wake diary for two weeks. The results showed that the students had high anxiety trait and state. Students who had high anxiety trait had an earlier sleep offset on weekdays and weekend, and students who displayed irregularity in the sleep/wake cycle had high anxiety state. These results suggest a relationship between the sleep/wake cycle and anxiety.

During sleep, humans experience the offline images and sensations that we call dreams, which are typically emotional and lacking in rational judgment of their bizarreness. However, during lucid dreaming (LD), subjects know that they are dreaming, and may control oneiric content. Dreaming and LD features have been studied in North Americans, Europeans and Asians, but not among Brazilians, the largest population in Latin America. Here we investigated dreams and LD characteristics in a Brazilian sample (n = 3,427; median age = 25 years) through an online survey. The subjects reported recalling dreams at least once a week (76%), and that dreams typically depicted actions (93%), known people (92%), sounds/voices (78%), and colored images (76%). The oneiric content was associated with plans for the upcoming days (37%), memories of the previous day (13%), or unrelated to the dreamer (30%). Nightmares usually depicted anxiety/fear (65%), being stalked (48%), or other unpleasant sensations (47%). These data corroborate Freudian notion of day residue in dreams, and suggest that dreams and nightmares are simulations of life situations that are related to our psychobiological integrity. Regarding LD, we observed that 77% of the subjects experienced LD at least once in life (44% up to 10 episodes ever), and for 48% LD subjectively lasted less than 1 min. LD frequency correlated weakly with dream recall frequency (r = 0.20, p < 0.01), and LD control was rare (29%). LD occurrence was facilitated when subjects did not need to wake up early (38%), a situation that increases rapid eye movement sleep (REMS) duration, or when subjects were under stress (30%), which increases REMS transitions into waking. These results indicate that LD is relatively ubiquitous but rare, unstable, difficult to control, and facilitated by increases in REMS duration and transitions to wake state. Together with LD incidence in USA, Europe and Asia, our data from Latin America strengthen the notion that LD is a general phenomenon of the human species.

Three experiments examined students' long-term retention of knowledge learned in college courses. In Experiment 1 retention was measured 4 and 11 months after the term ended. Students retained a great deal of what they originally learned, and there were no differential forgetting effects as a function of level of original learning. Experiment 2 compared retention for recall test items and 3 types of multiple-choice test items: recognition, comprehension, and mental skills. Students performed poorer on recall items, but there were no differences among the multiple-choice items measuring the other types of tasks. Experiment 3 analyzed retention for student tutors. Tutors retained more after 4 months than the students they tutored. This suggests that tutoring, a type of overlearning, has positive effects that are maintained over time.

Failure of severed adult central nervous system (CNS) axons to regenerate could be attributed with a reduced intrinsic growing capacity. Severe spinal cord injury is frequently associated with a permanent loss of function because the surviving neurons are impaired to regrow their fibers and to reestablish functional contacts. Peripheral nerves are known as good substrate for bridging CNS trauma with neurotrophic factor addition. We evaluated whether fibroblastic growth factor 2 (FGF-2) placed in a gap promoted by complete transection of the spinal cord may increase the ability of sciatic nerve graft to enhance motor recovery and fibers regrow. Methods: We used a complete spinal cord transection model. Rats received a 4 mm-long gap at low thoracic level and were repaired with saline (control) or fragment of the sciatic nerve (Nerve) or FGF-2 was added to nerve fragment (Nerve+FGF-2) to the grafts immediately after complete transection. The hind limbs performance was evaluated weekly for 8 weeks by using motor behavior score (BBB) and sensorimotor tests-linked to the combined behavior score (CBS), which indicate the degree of the motor improvement and the percentage of functional deficit, respectively. Neuronal plasticity were evaluated at the epicenter of the injury using MAP-2 and GAP-43 expression. Results: Spinal cord treatment with sciatic nerve and sciatic nerve plus FGF-2 allowed recovery of hind limb movements compared to control, manifested by significantly higher behavioral scores. Higher amounts of MAP-2 and GAP-43 immunoreactive fibers were found in the epicenter of the graft when FGF-2 was added. Conclusions: FGF-2 added to the nerve graft favored the motor recovery and fiber regrowth. Thus, these results encourage us to explore autologous transplantation as a novel and promising cell therapy for treatment of spinal cord lesion.

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Dream reports collected after rapid eye movement sleep (REM) awakenings are, on average, longer, more vivid, bizarre, emotional and story-like compared to those collected after non-REM. However, a comparison of the word-to-word structural organization of dream reports is lacking, and traditional measures that distinguish REM and non-REM dreaming may be confounded by report length. This problem is amenable to the analysis of dream reports as non-semantic directed word graphs, which provide a structural assessment of oral reports, while controlling for individual differences in verbosity. Against this background, the present study had two main aims: Firstly, to investigate differences in graph structure between REM and non-REM dream reports, and secondly, to evaluate how non-semantic directed word graph analysis compares to the widely used measure of report length in dream analysis. To do this, we analyzed a set of 133 dream reports obtained from 20 participants in controlled laboratory awakenings from REM and N2 sleep. We found that: (1) graphs from REM sleep possess a larger connectedness compared to those from N2; (2) measures of graph structure can predict ratings of dream complexity, where increases in connectedness and decreases in randomness are observed in relation to increasing dream report complexity; and (3) measures of the Largest Connected Component of a graph can improve a model containing report length in predicting sleep stage and dream report complexity. These results indicate that dream reports sampled after REM awakening have on average a larger connectedness compared to those sampled after N2 (i.e. words recur with a longer range), a difference which appears to be related to underlying differences in dream complexity. Altogether, graph analysis represents a promising method for dream research, due to its automated nature and potential to complement report length in dream analysis.

ResumoContexto: Os transtornos do sono são freqüentemente associados a um leque de transtornos psiquiátricos, sendo considerados uma característica inerente do transtorno depressivo. Objetivos: Discorrer acerca das atuais evidências sobre as investigações do sono e das alterações deste na depressão, além de alguns dos principais modelos teóricos propostos para explicar essas alterações. Métodos: O levantamento da literatura médica foi feito nos seguintes bancos de dados: ISI e Medline. Resultados: Diversos estudos constataram alterações no padrão eletroencefalográfico do sono em pacientes com depressão. Dentre os principais achados, estão alterações na continuidade e na duração do sono, diminuição das fases 3 e 4 do sono, menor latência do sono REM (rapid eye movements) e maior duração e densidade do primeiro período REM. Essa técnica tem atualmente uma utilidade limitada como ferramenta de diagnóstico na depressão. Conclusões: Embora os mecanismos fisiopatológicos das alterações do sono na depressão sejam complexos e de natureza multifacetada, os estudos do sono têm um importante papel na investigação da depressão, particularmente nas áreas de predição de resposta a tratamentos, prognóstico de recaídas e na investigação de modelos etiológicos. Chellappa, S.L.; Araújo, J.F. / Rev. Psiq. Clín 34 (6); 285-289, 2007Palavras-chave: Sono, transtornos do sono, distúrbios do início e da manutenção do sono, transtorno depressivo, saúde mental. AbstractBackground: Sleep disorders are usually associated with a wide range of psychiatric disorders, and are regarded as a characteristic feature of depression. Objectives: To report the current state-of-the-art in sleep research in depression and to present some of the principal theoretical models that explain these sleep disturbances. Methods: Literature review was carried out in the ISI and Medline databases. Results: Several studies have indicated alterations in sleep electroencephalographic patterns in subjects with depression. Some of the most frequent findings are disorders affecting the continuity and duration of sleep, reduction of phases 3 and 4 of sleep, decreased REM (rapid eye movements) sleep latency, and prolonged and intense first period of REM sleep. This technique is currently of limited use as a diagnostic tool in depression. Conclusions: AAlthough the pathophysiological mechanisms of sleep disorders in depression are complex, sleep studies play a key role in investigative research in depression, particularly in areas regarding prediction of responses to treatment, prognosis of relapses, and etiological models regarding depression.

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