Quinolinic acid lesions of the pedunculopontine nucleus impair sleep architecture, but not locomotion, exploration, emotionality or working memory in the rat.

Anatomical and functional studies have shown that the NADPH-diaphorase-positive cholinergic neurons of the pedunculopontine nucleus (PPN) send projections to several areas in the brain. The purpose of this work was to investigate whether bilateral lesions with quinolinic acid, a neurotoxin with greater selectivity for NADPH-diaphorase-positive neurons, aimed at the compact portion of the PPN would affect the performance of adaptive behaviors, such as sleep, locomotion, and spontaneous alternation. Lesioned animals were divided in a low lesion group (LL, <50% neuron loss) and a high lesion group (HL, ≥50% neuron loss).

Folate, homocysteine, interleukin-6, and tumor necrosis factor alfa levels, but not the methylenetetrahydrofolate reductase C677T polymorphism, are risk factors for schizophrenia.

The methylenetetrahydrofolate reductase (MTHFR) C677T mutation has been associated to high homocysteine levels and schizophrenia. Since cytokines are altered in schizophrenia and increments of homocysteine could promote an inflammatory response, it was investigated whether interleukin-6 (IL-6) and tumor necrosis factor alfa (TNFalpha) levels are modulated by the MTHFR genotype. Serum levels of TNFalpha, IL-6, B(12), homocysteine, folate and red blood cell (RBC) folate as well as the MTHFR genotype were determined in a group of schizophrenic patients and compared to those of a control group.

Evaluation of depressive symptoms and sleep alterations in college students.

Background: Increasing evidence suggests that sleep alterations could favor subsequent depression development. In order to identify the simultaneous occurrence of these parameters in young people, in this work we evaluated the prevalence of depressive symptoms, sleep habits, and possible sleep disturbances in college students.

Methods: Beck Depression Inventory (BDI), Epworth Sleepiness Scale (ESS), and a Sleep Habits Questionnaire were applied to students registered at the Autonomous University of Yucatan, Merida (mean age 20.

Sleep and memory deficits in the rat produced by experimental infection with Trypanosoma cruzi.

We investigated whether the infection with Trypanosoma cruzi in rats could produce functional alterations of the central nervous system. The experimental group received an injection of 150,000 trypomastigotes / rat, whereas the control group received a saline injection. Spontaneous alternation behavior (SAB) tests and sleep-wake cycle recordings were obtained at the end of the parasitaemia.