Normal Organization (normal + organization)

Distribution by Scientific Domains


Selected Abstracts


The maintenance of specific aspects of neuronal function and behavior is dependent on programmed cell death of adult-generated neurons in the dentate gyrus

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 7 2009
Woon Ryoung Kim
Abstract A considerable number of new neurons are generated daily in the dentate gyrus (DG) of the adult hippocampus, but only a subset of these survive, as many adult-generated neurons undergo programmed cell death (PCD). However, the significance of PCD in the adult brain for the functionality of DG circuits is not known. Here, we examined the electrophysiological and behavioral characteristics of Bax -knockout (Bax -KO) mice in which PCD of post-mitotic neurons is prevented. The continuous increase in DG cell numbers in Bax -KO mice resulted in the readjustment of afferent and efferent synaptic connections, represented by age-dependent reductions in the dendritic arborization of DG neurons and in the synaptic contact ratio of mossy fibers with CA3 dendritic spines. These neuroanatomical changes were associated with reductions in synaptic transmission and reduced performance in a contextual fear memory task in 6-month-old Bax -KO mice. These results suggest that the elimination of excess DG neurons via Bax -dependent PCD in the adult brain is required for the normal organization and function of the hippocampus. [source]


Roles of bone morphogenetic protein signaling and its antagonism in holoprosencephaly,

AMERICAN JOURNAL OF MEDICAL GENETICS, Issue 1 2010
John Klingensmith
Abstract Holoprosencephaly (HPE) is the most common malformation of the forebrain, resulting from a failure to completely septate the left and right hemispheres at the rostral end of the neural tube. Because of the tissue interactions that drive head development, these forebrain defects are typically accompanied by midline deficiencies of craniofacial structures. Early events in setting up tissue precursors of the head, as well as later interactions between these tissues, are critical for normal head formation. Defects in either process can result in HPE. Signaling by bone morphogenetic proteins (BMPs), a family of secreted cytokines, generally plays negative roles in early stages of head formation, and thus must be attenuated in multiple contexts to ensure proper forebrain and craniofacial development. Chordin and Noggin are endogenous, extracellular antagonists of BMP signaling that promote the normal organization of the forebrain and face. Mouse mutants with reduced levels of both factors display mutant phenotypes remarkably analogous to the range of malformations seen in human HPE sequence. Chordin and Noggin function in part by antagonizing the inhibitory effects of BMP signaling on the Sonic hedgehog and Nodal pathways, genetic lesions in each being associated with human HPE. Study of Chordin;Noggin mutant mice is helping us to understand the molecular, cellular, and genetic pathogenesis of HPE and associated malformations. 2010 Wiley-Liss, Inc. [source]


DIFFERENCES BETWEEN PATHOLOGICAL AND PHYSIOLOGICAL CARDIAC HYPERTROPHY: NOVEL THERAPEUTIC STRATEGIES TO TREAT HEART FAILURE

CLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 4 2007
Julie R McMullen
SUMMARY 1In general, cardiac hypertrophy (an increase in heart mass) is a poor prognostic sign. Cardiac enlargement is a characteristic of most forms of heart failure. Cardiac hypertrophy that occurs in athletes (physiological hypertrophy) is a notable exception. 2Physiological cardiac hypertrophy in response to exercise training differs in its structural and molecular profile to pathological hypertrophy associated with pressure or volume overload in disease. Physiological hypertrophy is characterized by normal organization of cardiac structure and normal or enhanced cardiac function, whereas pathological hypertrophy is commonly associated with upregulation of fetal genes, fibrosis, cardiac dysfunction and increased mortality. 3It is now clear that several signalling molecules play unique roles in the regulation of pathological and physiological cardiac hypertrophy. 4The present review discusses the possibility of targeting cardioprotective signalling pathways and genes activated in the athlete's heart to treat or prevent heart failure. [source]


Parental rearing and substance related disorders,a multi-factorial controlled study in a Swedish sample

CLINICAL PSYCHOLOGY AND PSYCHOTHERAPY (AN INTERNATIONAL JOURNAL OF THEORY & PRACTICE), Issue 6 2004
P. Andersson
Dysfunctional parental rearing was investigated to evaluate cognitive self-protective strategies in a high-risk sample from the Methadone Maintenance Programme, Stockholm, Sweden, and healthy subjects respectively. The Bowlby-Scale, the ASQ-SWED, the Reciprocal Attachment Questionnaire, the Dysfunctional Attitudes Scale and the Dysfunctional Working Models Scale were used. Results confirm insecure attachment (types A, C, D) among addicts and secure attachment (type B) among controls. The influence of the pathological pattern Compulsive self-reliance on the personality factor Confidence in self and others was 40.3 times higher (odds ratio) for addicts. The content of schemas in substance-related disorders shows an individual vulnerability associated with a decreased social competence and a very high risk for the development of various types of psychopathology. On the other hand, findings obtained in control subjects attest to a ,normal' organization of self-protective strategies and a pattern of behaviour mainly based on secure attachment.,Copyright 2004 John Wiley & Sons, Ltd. [source]