ABSTRACT
Vesicular monoamine transporters (VMAT) are involved in presynaptic storage and release of neurotransmitters. While it was thought initially that only VMAT2 is brain expressed and VMAT1 is present only in the periphery, recent data have challenged the exclusive expression of VMAT2 in the brain. To further elucidate the role of VMAT1 brain expression and its potential role in neuropsychiatric disorders, we have investigated mice lacking VMAT1. Comparison of wildtype and knock-out (KO) mice using qPCR and immunohistochemistry documents the expression of VMAT1 in the brain. Deletion of VMAT1 leads to increased hippocampal apoptosis and reduced neurogenesis as assessed by caspase-3-labeling and 5-bromo-deoxy-uridine-labeling. Behavioral data show that mice lacking VMAT1 have neurocognitive deficits. VMAT2 expression is not altered in VMAT1 KO mice, suggesting a distinct role of VMAT1. Our data support VMAT1 brain expression and suggest that VMAT1 plays a key role in survival of hippocampal neurons and thus might contribute to neurocognitive deficits observed in neuropsychiatric disorders.
Subject(s)
Brain/physiopathology , Cognition Disorders/physiopathology , Discrimination, Psychological/physiology , Neurons/pathology , Space Perception/physiology , Vesicular Monoamine Transport Proteins/deficiency , Animals , Apoptosis/physiology , Brain/pathology , Caspase 3/metabolism , Cognition Disorders/pathology , Conditioning, Psychological/physiology , Fear/physiology , Male , Mice, Knockout , Neurogenesis/physiology , Neurons/physiology , RNA, Messenger/metabolism , Recognition, Psychology/physiology , Synaptophysin/metabolism , Vesicular Monoamine Transport Proteins/genetics , Vesicular Monoamine Transport Proteins/metabolismABSTRACT
To explore the way that children's cognitive functioning relates to stressors they report experiencing in every day life, this study used the approach of cognitive control theory, which defines cognition as a set of mobile functions that, in serving adaptation, shift in their organization. Children (N = 93), ranging in age from 56 to 115 months, were administered individually the Life Stressor Interview and several cognitive control tasks. Children who reported being exposed to arguments and threatening gestures among adults made more errors when focusing attention while distracted by stimuli concerning nurture. Children who reported being upset by shootings and fights had more difficulty remembering test information depicting two persons in a shoot-out. The results are discussed in terms of the potential value of an approach that integrates cognitive activity with personality.
Subject(s)
Internal-External Control , Life Change Events , Personality Development , Urban Population , Aggression/psychology , Attention , Child , Child, Preschool , Defense Mechanisms , Female , Humans , Interpersonal Relations , Male , Mental Recall , Socioeconomic FactorsABSTRACT
Los autores, después de un breve estudio de las vicisitudes que experimentan los antidepresivos desde que se ingieren por vía oral o parenteral en el organismo y de la utilidad de medir los niveles plasmáticos, se ocupan de las más recientes investigaciones sobre el mecanismo de acción de los mismos, superando las posiciones simplistas de sus relaciones con los neurotransmisores y los receptores sinápticos. Se señalan las diferencias conocidas entre los diversos antidepresivos, comparando las situaciones de las sinapsis en estado eutímico y depresivo sin tratamiento con las que se producen con los distintos antidepresivos. La conclusión más importante es que el mecanismo íntimo de acción de los antidepresivos todavía es poco conocido, siendo fundamental su intervención en la cascada de acontecimientos postsinápticos que llevan por transducción la señal hasta el genoma, planteando una nueva comprensión entre factores genéticos y ambientales en la depresión.. (AU)
