RESUMO
Individual differences in cognitive performance are partly dependent, on genetic polymporhisms. One of the single-nucleotide polymorphisms (SNP) of the CNR1 gene, which codes for cannabinoid receptor 1 (CB1R), is the rs2180619, located in a regulatory region of this gene (6q14-q15). The alleles of the rs2180619 are A > G; the G allele has been associated with addiction and high levels of anxiety (when the G allele interacts with the SS genotype of the 5-HTTLPR gene). However, GG genotype is observed also in healthy subjects. Considering G allele as risk for 'psychopathological conditions', it is possible that GG healthy subjects do not be addicted or anxious, but would have reduced performance, compared to AA subjects, in attentional control and working memory processing. One hundred and sixty-four healthy young Mexican-Mestizo subjects (100 women and 64, men; mean age: 22.86 years, SD=2.72) participated in this study, solving a task where attentional control and working memory were required. GG subjects, compared to AA subjects showed: (1) a general lower performance in the task (P = 0.02); (2) lower performance only when a high load of information was held in working memory (P = 0.02); and (3) a higher vulnerability to distractors (P = 0.03). Our results suggest that, although the performance of GG subjects was at normal levels, a lower efficiency of the endocannabinoid system, probably due to a lowered expression of CB1R, produced a reduction in the performance of these subjects when attentional control and working memory processing is challenged.
Assuntos
Atenção , Memória de Curto Prazo , Polimorfismo de Nucleotídeo Único , Receptor CB1 de Canabinoide/genética , Adulto , Feminino , Estudos de Associação Genética , Humanos , MasculinoRESUMO
Digestive and metabolic processes are entrained by restricted feeding (RFS) schedules and are thought to be potential elements of a food-entrained oscillator (FEO). Due to the close relationship of leptin with metabolic regulation and because leptin is a relevant communication signal of the individual's peripheral metabolic condition with the central nervous system, we explored whether leptin is an endogenous entraining signal from the periphery to a central element of an FEO. First we characterized in the rat the diurnal rhythm of serum leptin (in rats fed ad libitum (AL)), its adjustment to an RFS and the influence of fasting after RFS, or RFS followed by AL feeding and then total food deprivation (RF-AF) in the persistence of this fluctuating pattern. We also explored the response of free fatty acids and stomach weight under the same entraining conditions. We compared the metabolic response with the behavioral expression of drinking anticipatory activity (AA) under the same conditions. Finally, we tested the effect of daily i.c.v administration of leptin as a putative entraining signal for the generation of AA. Metabolic parameters responded to food entrainment by adjusting their phase to mealtime. However, leptin and free fatty acid rhythms persisted only for a few cycles in fasting conditions and readjusted to the light-darkness cycle after an RF-AF protocol. In contrast, behavioral food-entrained rhythms persisted after both fasting manipulations. Daily leptin i.c.v. administration did not produce AA, nor produce changes in the behavioral free-running rhythm. Stomach weight indicated an adaptive process allowing an extreme stomach distension followed by a slow emptying process, which suggests that the stomach may be playing a relevant role as a storage organ. In conclusion, metabolic signals here studied respond to feeding schedules by adjusting their phase to mealtime, but do only persist for a few cycles in fasting. Leptin does not produce AA and thus is not an entraining signal for FEO. The response of metabolic signals to feeding schedules depends on different mechanisms than the expression of AA.
Assuntos
Adaptação Fisiológica , Tecido Adiposo/metabolismo , Privação de Alimentos , Leptina/farmacologia , Transdução de Sinais/fisiologia , Animais , Comportamento Alimentar , Masculino , Ratos , Ratos WistarRESUMO
The present article is the adapted version of an electronic symposium organized by the Brazilian Society of Neuroscience and Behavior (SBNeC) which took place on June 14, 2000. The text is divided into three sections: I. The main issues, II. Chronodrugs, and III. Methods. The first section is dedicated to the perspectives of chronobiology for the next decade, with opinions about the trends of future research being emitted and discussed. The second section deals mostly with drugs acting or potentially acting on the organism's timing systems. In the third section there are considerations about relevant methodological issues concerning data analysis.
Assuntos
Encéfalo/fisiologia , Fenômenos Cronobiológicos/fisiologia , Pesquisa/tendências , Encéfalo/efeitos dos fármacos , Fenômenos Cronobiológicos/efeitos dos fármacos , Cronoterapia , Redes de Comunicação de Computadores , HumanosRESUMO
The present article is the adapted version of an electronic symposium organized by the Brazilian Society of Neuroscience and Behavior (SBNeC) which took place on June 14, 2000. The text is divided into three sections: I. The main issues, II. Chronodrugs, and III. Methods. The first section is dedicated to the perspectives of chronobiology for the next decade, with opinions about the trends of future research being emitted and discussed. The second section deals mostly with drugs acting or potentially acting on the organism's timing systems. In the third section there are considerations about relevant methodological issues concerning data analysis
Assuntos
Humanos , Encéfalo/fisiologia , Cronobiologia/fisiologia , Pesquisa/tendências , Encéfalo/efeitos dos fármacos , Cronobiologia/efeitos dos fármacos , Redes de Comunicação de ComputadoresRESUMO
Seven cases of sexual behavior during sleep (SBS) have been recently reported. The subjects had histories of behavioral parasomnias as well as positive family histories of parasomnia. A 27 year-old man with a history of sexual behavior during sleep was reported. His sleep history disclosed sleepwalking (SW) since 9 years of age. He also developed episodes of highly disruptive and violent nocturnal behavior with dream enactment at age 20 years, which often resulted in physical injuries either to himself or his wife and infant. His wife also reported episodes of amnestic sexual behavior that began 4 years before referral. During the episodes, the patient typically procured his wife, achieving complete sexual intercourse with total amnesia. Physical and neurological diagnostic workups were unremarkable. Family history disclosed sleepwalking in his brother. He was put on 2mg/day of bedtime clonazepam with a remarkable clinical improvement. This case involves either the combination of violent and non-violent sleepwalking with SBS, or the superimposition of presumed REM sleep behavior disorder (RBD) on top of preexisting SW in a man who also developed SBS in adulthood. Thus, this is a case report of probable parasomnia overlap syndrome.
Assuntos
Transtorno do Comportamento do Sono REM/fisiopatologia , Comportamento Sexual/fisiologia , Sono/fisiologia , Sonambulismo/fisiopatologia , Adulto , Anticonvulsivantes/uso terapêutico , Clonazepam/uso terapêutico , Eletroencefalografia , Eletromiografia , Humanos , Masculino , Transtorno do Comportamento do Sono REM/tratamento farmacológico , Transtorno do Comportamento do Sono REM/patologia , Comportamento Sexual/efeitos dos fármacos , Sono/efeitos dos fármacos , Sonambulismo/tratamento farmacológicoRESUMO
In the rat the pelvic nerve consists of a viscerocutaneous (sensory) branch which receives information from pelvic viscera and the midline perineal region, and a somatomotor (muscular) branch which innervates the ilio- and pubococcygeous muscles. To investigate the contribution of these branches to the parturition process, the length of gestation and course of delivery were closely monitored in 43 pregnant, Wistar-strain rats randomly assigned to five groups: untreated control animals, animals in which the somatomotor branch of the pelvic nerve was bilaterally sectioned on Day 14 of gestation, animals in which the viscerocutaneous branch of the pelvic nerve was bilaterally sectioned on Day 14 of gestation, animals treated similarly to the previous group but with young delivered by C-section at term, and sham-operated controls. Sectioning the viscerocutaneous branch seriously disrupted parturition and resulted in major dystocia and a high percentage of stillbirths in all females. In contrast, sectioning the somatomotor branch had no apparent effect on parturition and no significant differences were found between females of this group and sham or control dams on any of the measures recorded. It is concluded that the viscerocutaneous branch of the pelvic nerve is vital for the normal course of parturition in the rat but that the somatomotor branch plays little role, if any.
Assuntos
Músculos Abdominais/inervação , Trabalho de Parto/fisiologia , Neurônios Motores/fisiologia , Diafragma da Pelve/inervação , Células Receptoras Sensoriais/fisiologia , Animais , Feminino , Tamanho da Ninhada de Vivíparos , Nervos Periféricos/fisiologia , Gravidez , RatosRESUMO
Evidence in support for the concept of the so-called 'siesta culture' is not well developed and has, to date, relied largely on qualitative anthropological data. Presumably such cultures are characterized by a strong tendency for daytime naps and daytime sleepiness, phenomena which may partially represent the effects of geographic, climatic or light conditions and/or cultural influences. In this study we surveyed the nocturnal sleep habits and daytime sleep tendencies of 577 Mexican college students residing in Mexico City (19 degrees N latitude). Results indicated a number of parallels between the reported sleep habits of these students and those reported from other cultures at latitudes far to the north (North America, Europe), such as longer sleep at the weekends, an association between snoring and daytime sleepiness and a lack of relationship between nocturnal sleep duration and the reported tendency to nap. There was some suggestion that these Mexican students may actually nap less when compared to other college student populations. Taken together, these results call into question what is meant by the concept of a 'siesta culture', at least in this urban, educated, upper social economic scale (SES) population, and suggest that future studies in equatorial regions be undertaken to further appreciate the role of climate, photoperiod and/or culture in the tendency for humans to nap during the day.
Assuntos
Cultura , Sono/fisiologia , Estudantes/psicologia , População Urbana , Adolescente , Adulto , Fatores Etários , Estudos de Coortes , Distúrbios do Sono por Sonolência Excessiva/diagnóstico , Feminino , Humanos , Masculino , México , Sono/efeitos dos fármacos , Ronco/diagnóstico , Inquéritos e Questionários , Fatores de Tempo , VigíliaRESUMO
In order to characterize how suprachiasmatic nuclei (SCN) neurons integrate its visual inputs, extracellular responses from SCN and adjacent hypothalamic neurons were recorded after stimulation of either the retina, the intergeniculate leaflet (IGL) or both simultaneously. Individual stimulation of either structure elicited excitatory or inhibitory responses in 36% of SCN and 20% of non-SCN neurons. Three subpopulations of SCN neurons were found, the first two responding exclusively either to the retina or the IGL, and the third responding to both the retina and the IGL. Simultaneous stimulation of the retina and the IGL induced a change in the firing pattern of some SCN neurons, which suggests modulatory regulation of SCN neuronal activity by synaptic interactions between its visual inputs.
Assuntos
Mapeamento Encefálico , Corpos Geniculados/fisiologia , Neurônios/fisiologia , Retina/fisiologia , Núcleo Supraquiasmático/fisiologia , Potenciais de Ação , Animais , Estimulação Elétrica , Masculino , Neurônios/citologia , Estimulação Luminosa , Ratos , Ratos Wistar , Núcleo Supraquiasmático/citologia , Percepção VisualRESUMO
The purpose of this study was to describe the factor structure of the Sleep-Wake Activity Inventory (SWAI) in a Mexican population. In a sample of 722 Mexican college students, we replicated five of the six factors originally described in the SWAI. Retained factors included: excessive daytime sleepiness (similarity coefficient of 0.735), psychic distress (0.609), social desirability (0.638), individual's ability to relax (0.864), and nocturnal sleep (0.660). These results confirm the factor structure and extend the possible utility of the SWAI in a siesta culture.
Assuntos
Sono , Vigília , Adolescente , Adulto , Distúrbios do Sono por Sonolência Excessiva/diagnóstico , Hispânico ou Latino , Humanos , Desejabilidade Social , Estresse Psicológico/psicologia , Estados Unidos/etnologiaRESUMO
Eight diurnally active (06:00-23:00 h) subjects were adapted for 2 days to the room conditions where the experiments were performed. Blood sampling for adenosine metabolites and metabolizing enzymes was done hourly during the activity span and every 30 min during sleep. The results showed that adenosine and its catabolites (inosine, hypoxanthine, and uric acid), adenosine synthesizing (S-adenosylhomocysteine hydrolase and 5'-nucleotidase), degrading (adenosine deaminase) and nucleotide-forming (adenosine kinase) enzymes as well as adenine nucleotides (AMP, ADP, and ATP) undergo statistically significant fluctuations (ANOVA) during the 24 h. However, energy charge was invariable. Glucose and lactate chronograms were determined as metabolic indicators. The same data analyzed by the chi-square periodogram and Fourier series indicated ultradian oscillatory periods for all the metabolites and enzymatic activities determined, and 24-h oscillatory components for inosine, hypoxanthine, adenine nucleotides, glucose, and the activities of SAH-hydrolase, 5'-nucleotidase, and adenosine kinase. The single cosinor method showed significant oscillatory components exclusively for lactate. As a whole, these results suggest that adenosine metabolism may play a role as a biological oscillator coordinating and/or modulating the energy homeostasis and physiological status of erythrocytes in vivo and could be an important factor in the distribution of purine rings for the rest of the organism.