Competition From New Neurons Drives Circuit Refinement In The Adult Dentate Gyrus

The hippocampus encodes sensory information into memories. The dentate gyrus (DG) region is viewed as the entry point into the hippocampus, receiving sensory and spatial signals from perforant path axons of the entorhinal cortex (EC). Ever since researchers discovered a neurogenic niche in the subgranular zone (SGZ) of the DG in adult animals and humans, many studies have been aimed at discovering how these continually proliferating granule cells (GCs) contribute to the network. Immature GCs have dendrites that project densely into the molecular layer alongside mature GCs and there is morphological evidence that immature excitatory spines preferentially synapse onto existing boutons. Therefore, it is likely that the addition of new GCs alters preexisting connections. Here we give an introduction to the possible functions of the DG and its relevance to human memory, then briefly review what is known about cell death, plasticity and synapse competition in the DG as well as other CNS regions. We then present a body of work that shows evidence for functional synaptic competition between immature and mature GCs. We also show that eliminating the pro-apoptotic Bax gene in mature GCs prevents competition-induced rewiring of the circuit. Finally, we discuss the implications of this work and present further evidence that manipulating neurogenesis affects the DG network

From benzos to berries: treatment offered at an Aboriginal youth solvent abuse treatment centre relays the importance of culture.

First Nations and Inuit youth who abuse solvents are one of the most highly stigmatized substance-abusing groups in Canada. Drawing on a residential treatment response that is grounded in a culture-based model of resiliency, this article discusses the cultural implications for psychiatry's individualized approach to treating mental disorders. A systematic review of articles published in The Canadian Journal of Psychiatry during the past decade, augmented with a review of Canadian and international literature, revealed a gap in understanding and practice between Western psychiatric disorder-based and Aboriginal culture-based approaches to treatment and healing from substance abuse and mental disorders. Differing conceptualizations of mental health and substance abuse are discussed from Western psychiatric and Aboriginal worldviews, with a focus on connection to self, community, and political context. Applying an Aboriginal method of knowledge translation-storytelling-experiences from front-line workers in a youth solvent abuse treatment centre relay the difficulties with applying Western responses to Aboriginal healing. This lends to a discussion of how psychiatry can capitalize on the growing debate regarding the role of culture in the treatment of Aboriginal youth who abuse solvents. There is significant need for culturally competent psychiatric research specific to diagnosing and treating First Nations and Inuit youth who abuse substances, including solvents. Such understanding for front-line psychiatrists is necessary to improve practice. A health promotion perspective may be a valuable beginning point for attaining this understanding, as it situates psychiatry's approach to treating mental disorders within the etiology for Aboriginal Peoples

An Exploratory Approach to Analyzing Alcohol Control Policy Opinions Held by Ontario Adults

Telephone interview data from a representative sample of 1,216 Ontario adults were analyzed using latent class analysis to determine whether distinct and homogeneous classes of individuals could be identified based on their responding patterns to 11 alcohol policy items. Five latent classes were identified and labeled as: dedicated liberalizers, moderate liberalizers, moderate controllers, dedicated controllers, and an ambivalent class. Multinomial regression analysis indicated that demographic and alcohol factors differentiated the classes. Those most opposed to alcohol controls, dedicated liberalizers, were more likely to be male, younger and heavier drinkers. Given their young age it is possible that further erosion of public support for alcohol controls may be expected

Enhanced Integration of Newborn Neurons after Neonatal Insults

The production and integration of adult-generated neurons in the dentate gyrus is dramatically perturbed by a variety of pathological insults, including repetitive seizures and hypoxia/ischemia. Less is known about how insults affect early postnatal neurogenesis, during the developmental period when the majority of dentate neurons are produced. Here we tested how single episodes of hypoxia or chemically induced seizure activity in postnatal day 10 mice alter granule cell production and integration. Although neither insult was sufficient to alter the number of newborn neurons nor the population of proliferating cells, both treatments increased the dendritic complexity of newborn granule cells that were born around the time of the insult. Surprisingly, only the dendritic enhancement caused by hypoxia was associated with increased synaptic integration. These results suggest that alterations in dendritic integration can be dissociated from altered neural production and that integration appears to have a lower threshold for perturbation. Furthermore, newborn neurons in adult mice that experienced neonatal hypoxia had reduced dendritic length while having no alterations in number. Together these results suggest that single insults during the neonatal period can have both long- and short-term consequences for neuronal maturation

Specialist or Nonspecialist Physical Education Teachers in Ontario Elementary Schools: Examining Differences in Opportunities for Physical Activity

Research supports the position that specialists are the preferred providers of physical education in elementary (primary) school settings. We examined whether specialists delivered more physical education lessons and provided greater opportunities for moderate and vigorous physical activity and whether barriers to curricular and extracurricular physical activity opportunities in Ontario elementary schools differed for specialist and nonspecialist teachers. Using a cross-sectional design, a questionnaire was mailed to key informants in 599 randomly selected elementary schools in Ontario, yielding an 85% response rate. Most physical education in Ontario elementary schools is delivered by nonspecialists (63%). No self-reported differences were found between specialists and generalist teachers in the number of physical education lessons delivered per week, the minutes per physical education class, or in the amount of reported moderate or vigorous physical activity in lessons. Compared with specialists, respondents in schools in which generalist teachers taught PE perceived lack of training as a greater barrier to delivering physical education. Given the importance of subject knowledge in teaching effectively, there is still need to advocate for specialist physical education teaching in elementary schools. However, concerns about teaching specialism may be secondary to broader and more complex factors surrounding the delivery of physical education in elementary schools.La recherche appuie le point de vue selon lequel les spécialistes sont les mieux placés pour enseigner l’éducation physique au primaire. Nous nous sommes penchés sur deux questions: (a) les spécialistes offrent-ils plus de cours d’éducation physique et d’occasions de pratiquer des activités physiques modérées ou vigoureuses ?, et (b) les obstacles à la participation aux activités physiques scolaires et extra-scolaires dans les écoles primaires de l’Ontario sont-ils les mêmes pour les enseignants spécialistes et les enseignants non-spécialistes ? Dans le contexte d’un modèle croisé, nous avons envoyé un questionnaire à des répondants clés dans 599 écoles primaires sélectionnées au hasard en Ontario. Notre taux de réponse a été de 85%. La majorité (63%) des cours d’éducation physique en Ontario sont offerts par des non spécialistes. Les résultats n’indiquent aucune différence entre les enseignants spécialistes et les enseignants non-spécialistes quant aux critères suivants: le nombre de cours d’éducation physique offerts par semaine, la durée des cours d’éducation physique et la mesure dans laquelle les cours impliquent de l’activité physique modérée ou vigoureuse. Par rapport aux répondants des écoles où les cours d’éducation physique se donnaient par des spécialistes, ceux des écoles où ces cours se donnaient par des généralistes ont indiqué que le manque de formation constituait un obstacle plus important à l’enseignement de l’éducation physique. Compte tenu du rôle important de la connaissance de la matière dans l’enseignement efficace, il faudrait continuer à promouvoir l’enseignement de l’éducation physique par des spécialistes dans les écoles primaires. Toutefois, les préoccupations portant sur l’enseignement par des spécialistes semblent secondaires face aux facteurs plus généraux et complexes en matière d’enseignement de l’éducation physique dans les écoles primaires

Familiares e pessoas conhecidas de usuários de drogas ilícitas: recorte de opiniões sobre leis e políticas públicas de uma comunidade da Zona Oeste do Rio de Janeiro, Brasil

This article is part of the study "Illicit Drug Use in Seven Latin American Countries and Canada: Critical Perspectives of Family and Familiars" (7LACC), which investigated four domains: protective and risk factors; preventive initiatives; treatment facilities; and laws and policies. The article presents a section of the results based on four items of the laws and policies domain - as perceived by the family and acquaintances of illicit drug users living in the community. Participants were recruited in urban primary health care units located in Western Rio de Janeiro (city), Brazil. This multi-method, cross-temporal study performed interviews with 100 adults (18 years of age or older), all cognitively healthy. Results and key conclusions included non-compliance with the fundamental principles of the Unique Health System Legislation / Law 8.080/90 and the erroneous implementation of laws and public policies on illicit drug.Este articulo forma parte del estudio "Uso de Drogas Ilícitas en Siete Países Latino Americanos y Canadá - Las Perspectivas Críticas de la Familia y de Personas Conocidas" (7LACC). Fueron investigados cuatro dominios: factores protectores y de riesgo; iniciativas inhibidoras; facilidades de tratamiento; y, leyes y políticas. Se presenta una sección de resultados relacionados a leyes y políticas, describiendo como ellas fueron percibidas por familiares y personas cercanas a los usuarios de drogas ilícitas, que estaban inscritos en unidades primarias urbanas de asistencia a la salud, situadas en la zona occidental de la ciudad de Río de Janeiro, en Brasil. Se trata de una investigación transversal, que utilizó múltiples métodos, en la cual fueron entrevistados 100 adultos, que tenían más de 18 años de edad, sin problemas cognoscitivos. Los resultados y las principales conclusiones fueron el incumplimiento de los principios fundamentales del Sistema Unificado de Salud (SUS) / Ley 8.080/90 y la inadecuada implementación de leyes y políticas públicas relacionadas a las drogas ilícitas.Este artigo é parte do estudo "Uso de drogas ilícitas em sete países latino-americanos e Canadá: perspectivas críticas de familiares e pessoas conhecidas" (7LACC) que investigou quatro domínios: fatores protetores e de risco, iniciativas de prevenção, unidades de tratamento e leis e políticas. Apresenta uma seção dos resultados baseados em quatro itens do domínio leis e políticas - como percebidas por familiares e pessoas conhecidas de usuários de drogas ilícitas, residentes na comunidade, recrutados em unidades urbanas de cuidados primários à saúde, localizadas na zona oeste da cidade do Rio de Janeiro. Trata-se de estudo corte temporal, multimétodos que entrevistou 100 adultos maiores de 18 anos, cognitivamente saudáveis. Resultados e conclusões chave foram o não atendimento dos princípios fundamentais da legislação do Sistema Único de Saúde (SUS)/Lei 8.080/90 e a equivocada aplicação das leis e políticas públicas sobre drogas ilícitas

Perspectiva crítica da família e pessoas próximas sobre fatores de risco familiares e comunitários em relaçâo ao uso de drogas ilícitas em São José, Costa Rica

This article presents the results of a quantitative study. The purpose was to describe the perspective of family members and acquaintances of illicit drug users about family and community risk factors that can contribute to addiction to illicit drugs. A questionnaire was used for data collection. The population consisted of 100 individuals, 18 years of age or older, who reported being affected by their relationship with an illicit drug user (relative or acquaintance). Most users (82%) were men, with an average age of 27.3 years. Family risk factors included: family rejection (99%), not feeling loved (98%), lack of communication (95%), family conflicts and violence (95%). Social or community factors included: 99% having friends who use drugs, 99% peer pressure, 93% living in an unsafe area, and 99% experienced a stressful event. The critical perspective proposes to use more prevention strategies to avoid risk factors in the family and community.En este estudio se presentan los resultados de una investigación cuantitativa, parte de un estudio multicéntrico, cuyo objetivo fue describir las perspectivas que tienen la familia y las personas cercanas a usuarios de drogas ilícitas, cuestionándose sobre cuáles serían los factores de riesgo familiar y comunitario que contribuyen a la adicción de drogas ilícitas. Se encuestó a 100 sujetos mayores de 18 años, familiares o personas cercanas a sujetos que han estado usado drogas ilícitas. Se encontró que la mayoría eran hombres, con edad promedio de 27.3 años. Los factores de riesgo provenientes de la familia identificados fueron: ser rechazado 99%, sentirse no amado 98%, falta de comunicación 95%, conflictos y violencia familiar 95%. Los factores sociales o comunitarios fueron: 99% tener amigos que usan drogas, 99% presión de los amigos, 93% vivir en un área insegura y 94% experimentar un evento estresante. Se concluyó, según su perspectiva crítica, que se debe trabajar más sobre las estrategias de prevención de factores de riesgo tanto en la familia como en la comunidad.São apresentados aqui os resultados de pesquisa quantitativa, cujo objetivo foi descrever as perspectivas da família e das pessoas próximas aos usúarios de drogas ilícitas, sobre os fatores de risco familiar e comunitário que contribuem para a adição de drogas ilícitas. Utilizou-se questionário aplicado em população de 100 pessoas, maiores de 18 anos, que se identificaram como afetadas por terem relação com familiar ou pessoa próxima que usa ou têm usado drogas ilícitas. Dentre os usuários, 82% eram homens, tinham idade média de 27,3 anos. Os fatores de risco familiares foram a rejeição pela família (99%), não se sentir amado (98%), falta de comunicação (95%), conflitos e violência familiar (95%). Fatores sociais ou comunitários: 99% referem ter amigos que usam drogas, 99% pressão dos amigos, 93% pelo fato de viverem em área sem segurança e 99% por experimentar um evento estressante. A perspectiva crítica propõe trabalhar mais sobre estratégias de prevenção de fatores de risco na família e na comunidade

El uso de las drogas ilícitas: perspectiva de familias y familiares en la Zona Central de Rio de Janeiro, Brazil

This article presents the partial results of a multicenter, cross-temporal study, which was performed using multiple methods, and involved seven Latin-American countries and Canada. The results presented refer to the city center of Rio de Janeiro (n=108). The central question of the study was: "How do illicit drug users' relatives and acquaintances describe protective and risk factors, prevention initiatives, treatment services, laws and policies regarding illicit drugs?" The quantitative data was collected using an instrument containing closed questions. In total, 108 young adults (18 years of age or older) were interviewed, who stated being affected by the drug although they were not users. For 104 interviewees (96%), negligence is the family dynamics that causes the greatest exposure to drugs, and 106 (98%) consider that parent support is what offers the greatest protection. Policies, the police and the criminal system have neither reduced drug use nor do they protect users.El trabajo presenta resultados cuantitativos de Brasil; el estudio se realizó en el centro de la ciudad de Río de Janeiro (n=108); es parte de una investigación multicéntrica, multimétodos y de corte temporal, en la que participaron a siete países Latinoamericanos y Canadá. La pregunta central del estudio fue "¿Cómo describen los familiares y las personas próximas a los usuarios de drogas ilegales los factores de protección y de riesgo, las iniciativas de prevención, los servicios de tratamiento, las leyes y las políticas sobre drogas ilegales?". Los datos cuantitativos fueron recolectados a través de un cuestionario con preguntas cerradas, que fue aplicado en 108 jóvenes adultos mayores de 18años, que se identificaron como personalmente afectados por la droga sin ser usuarios. Se encontró que para 104 de los entrevistados(96%), la dinámica familiar que más expone a la droga es la negligencia; también que la política, la policía y el sistema criminal no han disminuido el consumo de drogas y no protegen al usuario.O trabalho apresenta resultados quantitativos do Brasil, recorte centro da cidade do Rio de Janeiro (n=108), de uma pesquisa multicêntrica, multimétodos e corte temporal, envolvendo sete países latino-americanos e Canadá. A pergunta central da pesquisa foi "como familiares e pessoas próximas a usuários de drogas ilícitas descrevem fatores de proteção e de risco, iniciativas de prevenção, serviços de tratamento, leis e políticas sobre as drogas ilícitas". Os dados quantitativos foram coletados por meio de instrumento com perguntas fechadas, aplicados em 108 jovens adultos >;18anos que se identificaram como pessoalmente afetados pela droga sem serem usuários. Para 104 entrevistados (96%), a dinâmica familiar que mais expõe à droga é a negligência e, para 106 (98%), a que mais protege é a relação de apoio com os pais. A política, a polícia e o sistema criminal não têm diminuído o consumo e não protegem o usuário

Farmer Health and Adaptive Capacity in the Face of Climate Change and Variability. Part 2: Contexts, Personal Attributes and Behaviors

This study extends the emerging body of research on farmer adaptation to climate change, by segmenting farmers on the basis of specific attributes (health, values, belief about climate change, sense of responsibility for climate change, desire to change, social, human and financial capitals and farmer demographics) and considering such attributes as critical social aspects of the contextualized capacity to adapt. The segmental analysis was based on a nationally representative sample of 3,993 farmers concerned with farmer adaptation of climate risks. The resulting data were subjected to two-step cluster analysis to identify homogenous groups of farmers based on factors related to climate change adaptation. A three-cluster solution was identified wherein farmers were distinguishable on the basis of belief in climate change, desire for financial assistance and advice, social connectedness, information seeking, and adverse farm conditions. The largest group (Cluster 1: 55%) was characterized by farmers who recognized being affected by drought and drying and who were actively engaged in adaptive practices, despite the fact that they had little income and poor farm resources. One third of these farmers reported that their health was a barrier to sustained activity in farming. Cluster 2 (26%) was characterized by farmers not readily affected by drying, who enjoyed good incomes, good health and better farming conditions. They expressed little desire to adapt. The smallest cluster (Cluster 3: 19%) was also characterized by farmers who recognized that they were affected by drying. However, despite a desire to adapt, they had very little means to do so. They reported the poorest natural resources and the poorest health, despite being younger. The findings suggest that it is the intent to adapt, starting from where people are at, which is a more important indicator of the capacity to work towards sustainable practices than assets tests alone