RESUMEN
Synapses are pivotal sites of plasticity and memory formation. Consequently, synapses are energy consumption hotspots susceptible to dysfunction when their energy supplies are perturbed. Mitochondria are stabilized near synapses via the cytoskeleton and provide the local energy required for synaptic plasticity. However, the mechanisms that tether and stabilize mitochondria to support synaptic plasticity are unknown. We identified proteins exclusively tethering mitochondria to actin near postsynaptic spines. We find that VAP, the vesicle-associated membrane protein-associated protein implicated in amyotrophic lateral sclerosis, stabilizes mitochondria via actin near the spines. To test if the VAP-dependent stable mitochondrial compartments can locally support synaptic plasticity, we used two-photon glutamate uncaging for spine plasticity induction and investigated the induced and adjacent uninduced spines. We find VAP functions as a spatial stabilizer of mitochondrial compartments for up to ~60 min and as a spatial ruler determining the ~30 µm dendritic segment supported during synaptic plasticity.
Asunto(s)
Actinas , Espinas Dendríticas , Actinas/metabolismo , Espinas Dendríticas/metabolismo , Plasticidad Neuronal , Sinapsis/metabolismo , Mitocondrias/metabolismoRESUMEN
The existence of evolutionarily conserved regions in the vertebrate brain is well established. The rules and constraints underlying the evolution of neuron types, however, remain poorly understood. To compare neuron types across brain regions and species, we generated a cell type atlas of the brain of a bearded dragon and compared it with mouse datasets. Conserved classes of neurons could be identified from the expression of hundreds of genes, including homeodomain-type transcription factors and genes involved in connectivity. Within these classes, however, there are both conserved and divergent neuron types, precluding a simple categorization of the brain into ancestral and novel areas. In the thalamus, neuronal diversification correlates with the evolution of the cortex, suggesting that developmental origin and circuit allocation are drivers of neuronal identity and evolution.
Asunto(s)
Evolución Biológica , Corteza Cerebral , Expresión Génica , Lagartos , Neuronas , Animales , Corteza Cerebral/citología , Evolución Molecular , Perfilación de la Expresión Génica , Ratones , Neuronas/citología , Neuronas/metabolismoRESUMEN
College students who have high stress levels tend to experience an increased risk of academic difficulties, substance abuse, and emotional problems. To enhance student stress management and health promoting behaviors, an online stress management intervention called MyStudentBody-Stress (MyStudentBody-Stress) was developed and tested. College students at six U.S. colleges were randomized to one of three conditions: MyStudentBody-Stress, a control health information website, or no intervention. The differences between groups on stress control and health behavior measures were compared at baseline, and at 1, 3, and 6 months after baseline. Although there were no between-group differences on primary outcome variables, secondary analyses indicated that MyStudentBody-Stress participants were more likely to increase weekly physical activity, use specific stress management methods, and exhibit decreased anxiety and family problems. These findings indicate some potentially beneficial effects of online stress management programming for college students. Implications for college health practitioners are discussed.
Asunto(s)
Promoción de la Salud/métodos , Internet , Estrés Psicológico/terapia , Estudiantes/psicología , Adolescente , Adulto , Femenino , Humanos , Masculino , Estrés Psicológico/prevención & control , Estados Unidos , UniversidadesRESUMEN
The authors investigated the efficacy of an interactive Web site, MyStudentBody.com: Alcohol (MSB:Alcohol) that offers a brief, tailored intervention to help heavy drinking college students reduce their alcohol use. They conducted a randomized, controlled clinical trial to compare the intervention with an alcohol education Web site at baseline, postintervention, and 3-month follow-up. Students were assessed on various drinking measures and their readiness to change their drinking habits. The intervention was especially effective for women and persistent binge drinkers. Compared with women who used the control Web site, women who used the intervention significantly reduced their peak and total consumption during special occasions and also reported significantly fewer negative consequences related to drinking. In addition, persistent heavy binge drinkers in the experimental group experienced a more rapid decrease in average consumption and peak consumption compared with those in the control group. The authors judged MSB:Alcohol a useful intervention for reaching important subgroups of college binge drinkers.