Sex and sensitive period differences in potential effects of maltreatment on axial versus radial diffusivity in the corpus callosum

Background. Improvement of postural control in persons with multiple sclerosis (PwMS) is an important target for neurorehabilitation. Although PwMS are able to improve postural performance with training, the neural underpinnings of these improvements are poorly understood. Objective. To understand the neural underpinnings of postural motor learning in PwMS. Methods. Supraspinal white matter structural connectivity in PwMS was correlated with improvements in postural performance (balancing on an oscillating surface over 25 trials) and retention of improvements (24 hours later). Results. Improvement in postural performance was directly correlated to microstructural integrity of white matter tracts, measured as radial diffusivity, in the corpus callosum, posterior parieto-sensorimotor fibers and the brainstem in PwMS. Within the corpus callosum, the genu and midbody (fibers connecting the prefrontal and primary motor cortices, respectively) were most strongly correlated to improvements in postural control. Twenty-four-hour retention was not correlated to radial diffusivity. Conclusion. PwMS who exhibited poorer white matter tract integrity connecting the cortical hemispheres via the corpus callosum showed the most difficulty learning to control balance on an unstable surface. Prediction of improvements in postural control through training (ie, motor learning) via structural imaging of the brain may allow for identification of individuals who are particularly well suited for postural rehabilitation interventions.

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A role for ovarian hormones in sexual differentiation of the brain

Behavioral and Brain Sciences ◽

10.1017/s0140525x98001216 ◽

1998 ◽

Vol 21 (3) ◽

pp. 311-327 ◽

Cited By ~ 123

Author(s):

Roslyn Holly Fitch ◽

Victor H. Denenberg

Keyword(s):

Corpus Callosum ◽

Sexual Differentiation ◽

Ovarian Hormones ◽

Female Rats ◽

Sensitive Period ◽

Cross Sectional ◽

Androgen Treatment ◽

Female Brain ◽

Developmental Differentiation ◽

And Behavior

Historically, studies of the role of endogenous hormones in developmental differentiation of the sexes have suggested that mammalian sexual differentiation is mediated primarily by testicular androgens, and that exposure to androgens in early life leads to a male brain as defined by neuroanatomy and behavior. The female brain has been assumed to develop via a hormonal default mechanism, in the absence of androgen or other hormones. Ovarian hormones have significant effects on the development of a sexually dimorphic cortical structure, the corpus callosum, which is larger in male than in female rats. In the females, removal of the ovaries as late as Day 16 increases the cross-sectional area of the adult corpus callosum. Treatment with low-dose estradiol starting on Day 25 inhibits this effect. Female callosa are also enlarged by a combination of daily postnatal handling and exogenous testosterone administered prior to Day 8. The effects of androgen treatment are expressed early in development, with males and testosterone-treated females having larger callosa than control females as early as Day 30. The effects of ovariectomy do not appear until after Day 55. These findings are more consistent with other evidence of a later sensitive period for ovarian feminization as compared to androgenic masculinization.

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Corpus Callosum Microstructural Changes Correlate with Cognitive Dysfunction in Early Stages of Relapsing-Remitting Multiple Sclerosis: Axial and Radial Diffusivities Approach

Multiple Sclerosis International ◽

10.1155/2011/304875 ◽

2011 ◽

Vol 2011 ◽

pp. 1-7 ◽

Cited By ~ 7

Author(s):

Carolina de Medeiros Rimkus ◽

Thiago de Faria Junqueira ◽

Katarina Paz Lyra ◽

Marcel P. Jackowski ◽

Melissa A. R. Machado ◽

...

Keyword(s):

Multiple Sclerosis ◽

Corpus Callosum ◽

Mean Diffusivity ◽

Radial Diffusivity ◽

Cognitive Changes ◽

Promising Tool ◽

Axon Loss ◽

Relapsing Remitting ◽

The Central Nervous System ◽

Relapsing Remitting Multiple Sclerosis

The corpus callosum is the largest fiber bundle in the central nervous system and it takes part in several cognitive pathways. It can be affected by multiple sclerosis (MS) early in the disease. DTI is capable of infering the microstructural organization of the white matter. The vectorial analysis of the DTI offers the more specific indices of axial diffusivity (AD) and radial diffusivity (RD), which have shown to be useful to discriminate myelin damage from axon loss, respectively. This study presents DTI results (mean diffusivity (MD), fractional anisotropy (FA), RD, and AD) of 23 relapsing-remitting MS patients and its correlation with cognitive performance. There were 47.8% of cognitive impaired patients (MS CI). We found signs of demyelination, reflected by increased RD, and incipient axon loss, reflected by AD increase, which was slightly higher in the MS CI. The cognitive changes correlated with the DTI parameters, suggesting that loss of complexity in CC connections can impair neural conduction. Thus, cognitive impairment can be related to callosal disconnection, and DTI can be a promising tool to evaluate those changes.

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Decision letter for "Comparative morphology of the corpus callosum across the adult lifespan in chimpanzees ( Pan troglodytes ) and humans"

10.1002/cne.25039/v1/decision1 ◽

2020 ◽

Keyword(s):

Corpus Callosum ◽

Pan Troglodytes ◽

Comparative Morphology ◽

Adult Lifespan

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Review for "Comparative morphology of the corpus callosum across the adult lifespan in chimpanzees ( Pan troglodytes ) and humans"

10.1002/cne.25039/v2/review1 ◽

2020 ◽

Keyword(s):

Corpus Callosum ◽

Pan Troglodytes ◽

Comparative Morphology ◽

Adult Lifespan

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Treatment Considerations for Adolescents Who Exhibit Cognitive/Communication Problems: A Neuroscience Perspective

Perspectives of the ASHA Special Interest Groups ◽

10.1044/2020_persp-20-00071 ◽

2020 ◽

Vol 5 (6) ◽

pp. 1767-1775

Author(s):

Martha S. Burns

Keyword(s):

Social Communication ◽

Transition Period ◽

Clinical Intervention ◽

Review Article ◽

Sensitive Period ◽

Clinical Implications ◽

Evidence Based ◽

Communication Problems ◽

Treatment Considerations ◽

Behavioral Growth

Purpose Adolescence is a period of substantial neurophysiological and behavioral growth, representing a second sensitive period of brain development. It is a psychological and social transition period between childhood and adulthood with many beneficial changes occurring, especially with respect to potential responsiveness to clinical intervention. However, adolescent behavioral complexities introduce clinical challenges as well. The purpose of this review article is to review the current neuroimaging research on neurophysiological changes observed during adolescence and the cognitive and social behavioral counterparts, with specific attention to the clinical implications. The review article will then summarize currently available intervention tools that can be utilized by speech-language pathologists working with this population. It will conclude with available evidence-based social-communication approaches that may be applicable as well as available evidence-based supplemental technological cognitive interventions that may be useful in working with adolescents who exhibit language and communication issues. Conclusion As a transition period between childhood and adulthood, adolescence represents a second sensitive period during which there is opportunity for clinically derived beneficial cognitive and communication growth.

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