scholarly journals Mechanisms of function of neural grafts in the adult mammalian brain

1987 ◽  
Vol 132 (1) ◽  
pp. 265-289
Author(s):  
S. B. Dunnett ◽  
A. Bjorklund
Keyword(s):  
Recovery Of Function ◽  
Model Systems ◽  
Neural Systems ◽  
Mammalian Brain ◽  
Neural Tissues ◽  
Graft Tissue ◽  
And Function ◽  
Different Levels ◽  
Adult Mammalian Brain ◽  
Host Brain

Evidence for the survival, growth and function of grafted neural tissues in the adult mammalian brain is reviewed. In addition to considering the viability of grafts in the different model systems that have been investigated, consideration is given to alternative mechanisms by which the grafts might exert a functional influence over the host brain and the host animal's behaviour: (a) acute influence over spontaneous recovery of function, (b) chronic but diffuse secretion of neurochemicals into the host neuropile, (c) tonic reinnervation of the host brain, (d) bridging grafts, and (e) reciprocal reinnervation and full incorporation of graft tissue into host circuitry. It is concluded that no one mechanism is primary, but that different levels of reorganization can take place in different graft paradigms and neural systems.

scholarly journals Development of a Stereotaxic Device for Low Impact Implantation of Neural Constructs or Pieces of Neural Tissues into the Mammalian Brain

2014 ◽  
Vol 2014 ◽  
pp. 1-9
Author(s):  
Andrzej Jozwiak ◽  
Yiwen Liu ◽  
Ying Yang ◽  
Monte A. Gates
Keyword(s):  
Neural Tissue ◽  
Mammalian Brain ◽  
Point Contacts ◽  
Glass Capillary ◽  
Novel Technology ◽  
Neural Tissues ◽  
Thin Walled ◽  
Point To Point ◽  
Transplantation Procedures ◽  
Host Brain

Implanting pieces of tissue or scaffolding material into the mammalian central nervous system (CNS) is wrought with difficulties surrounding the size of tools needed to conduct such implants and the ability to maintain the orientation and integrity of the constructs during and after their transplantation. Here, novel technology has been developed that allows for the implantation of neural constructs or intact pieces of neural tissue into the CNS with low trauma. By “laying out” (instead of forcibly expelling) the implantable material from a thin walled glass capillary, this technology has the potential to enhance neural transplantation procedures by reducing trauma to the host brain during implantation and allowing for the implantation of engineered/dissected tissues or constructs in such a way that their orientation and integrity are maintained in the host. Such technology may be useful for treating various CNS disorders which require the reestablishment of point-to-point contacts (e.g., Parkinson’s disease) across the adult CNS, an environment which is not normally permissive to axonal growth.

scholarly journals Cadherins in early neural development

2021 ◽  
Author(s):  
Karolina Punovuori ◽  
Mattias Malaguti ◽  
Sally Lowell
Keyword(s):  
Adhesion Molecules ◽  
Cell Fate ◽  
Neural Development ◽  
Ex Vivo ◽  
Directed Differentiation ◽  
Culture Dish ◽  
Cell Identity ◽  
Cell Fate Decisions ◽  
Neural Tissues ◽  
And Function

AbstractDuring early neural development, changes in signalling inform the expression of transcription factors that in turn instruct changes in cell identity. At the same time, switches in adhesion molecule expression result in cellular rearrangements that define the morphology of the emerging neural tube. It is becoming increasingly clear that these two processes influence each other; adhesion molecules do not simply operate downstream of or in parallel with changes in cell identity but rather actively feed into cell fate decisions. Why are differentiation and adhesion so tightly linked? It is now over 60 years since Conrad Waddington noted the remarkable "Constancy of the Wild Type” (Waddington in Nature 183: 1654–1655, 1959) yet we still do not fully understand the mechanisms that make development so reproducible. Conversely, we do not understand why directed differentiation of cells in a dish is sometimes unpredictable and difficult to control. It has long been suggested that cells make decisions as 'local cooperatives' rather than as individuals (Gurdon in Nature 336: 772–774, 1988; Lander in Cell 144: 955–969, 2011). Given that the cadherin family of adhesion molecules can simultaneously influence morphogenesis and signalling, it is tempting to speculate that they may help coordinate cell fate decisions between neighbouring cells in the embryo to ensure fidelity of patterning, and that the uncoupling of these processes in a culture dish might underlie some of the problems with controlling cell fate decisions ex-vivo. Here we review the expression and function of cadherins during early neural development and discuss how and why they might modulate signalling and differentiation as neural tissues are formed.

scholarly journals Involvement of Thyroid Hormones in Brain Development and Cancer

Cancers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2693
Author(s):  
Gabriella Schiera ◽  
Carlo Maria Di Liegro ◽  
Italia Di Liegro
Keyword(s):  
Nervous System ◽  
Thyroid Hormones ◽  
Brain Development ◽  
Placental Transfer ◽  
Regulation Of Gene Expression ◽  
Mammalian Brain ◽  
Cancer Proliferation ◽  
Fetal Thyroid ◽  
Genomic Effects ◽  
And Function

The development and maturation of the mammalian brain are regulated by thyroid hormones (THs). Both hypothyroidism and hyperthyroidism cause serious anomalies in the organization and function of the nervous system. Most importantly, brain development is sensitive to TH supply well before the onset of the fetal thyroid function, and thus depends on the trans-placental transfer of maternal THs during pregnancy. Although the mechanism of action of THs mainly involves direct regulation of gene expression (genomic effects), mediated by nuclear receptors (THRs), it is now clear that THs can elicit cell responses also by binding to plasma membrane sites (non-genomic effects). Genomic and non-genomic effects of THs cooperate in modeling chromatin organization and function, thus controlling proliferation, maturation, and metabolism of the nervous system. However, the complex interplay of THs with their targets has also been suggested to impact cancer proliferation as well as metastatic processes. Herein, after discussing the general mechanisms of action of THs and their physiological effects on the nervous system, we will summarize a collection of data showing that thyroid hormone levels might influence cancer proliferation and invasion.

scholarly journals Regenerative capacity of neural precursors in the adult mammalian brain is under the control of p53

2009 ◽  
Vol 30 (3) ◽  
pp. 483-497 ◽  
Author(s):  
Silvia Medrano ◽  
Melissa Burns-Cusato ◽  
Marybless B. Atienza ◽  
Donya Rahimi ◽  
Heidi Scrable
Keyword(s):  
Mammalian Brain ◽  
Regenerative Capacity ◽  
Neural Precursors ◽  
Adult Mammalian Brain

Visual control of orientation behaviour in the fly: Part I. A quantitative analysis

1976 ◽  
Vol 9 (3) ◽  
pp. 311-375 ◽  
Author(s):  
Werner Reichardt ◽  
Tomaso Poggio
Keyword(s):  
Information Processing ◽  
Quantitative Analysis ◽  
Visual System ◽  
Sensory Information ◽  
Model Systems ◽  
Suitable Model ◽  
Logical Organization ◽  
Integrative Level ◽  
Processing Properties ◽  
Different Levels

An understanding of sensory information processing in the nervous system will probably require investigations with a variety of ‘model’ systems at different levels of complexity.Our choice of a suitable model system was constrained by two conflicting requirements: on one hand the information processing properties of the system should be rather complex, on the other hand the system should be amenable to a quantitative analysis. In this sense the fly represents a compromise.In these two papers we explore how optical information is processed by the fly's visual system. Our objective is to unravel the logical organization of the fly's visual system and its underlying functional and computational principles. Our approach is at a highly integrative level. There are different levels of analysing and ‘understanding’ complex systems, like a brain or a sophisticated computer.

scholarly journals The Expression and Distributions of ANP32A in the Developing Brain

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Shanshan Wang ◽  
Yunliang Wang ◽  
Qingshan Lu ◽  
Xinshan Liu ◽  
Fuyu Wang ◽  
...  
Keyword(s):  
Cerebral Cortex ◽  
Fetal Brain ◽  
Tissue Expression ◽  
Developing Brain ◽  
Adult Brain ◽  
Mammalian Brain ◽  
Dependent Manner ◽  
Growing Up ◽  
Embryonic Mouse ◽  
And Function

Acidic (leucine-rich) nuclear phosphoprotein 32 family, member A (ANP32A), has multiple functions involved in neuritogenesis, transcriptional regulation, and apoptosis. However, whether ANP32A has an effect on the mammalian developing brain is still in question. In this study, it was shown that brain was the organ that expressed the most abundant ANP32A by human multiple tissue expression (MTE) array. The distribution of ANP32A in the different adult brain areas was diverse dramatically, with high expression in cerebellum, temporal lobe, and cerebral cortex and with low expression in pons, medulla oblongata, and spinal cord. The expression of ANP32A was higher in the adult brain than in the fetal brain of not only humans but also mice in a time-dependent manner. ANP32A signals were dispersed accordantly in embryonic mouse brain. However, ANP32A was abundant in the granular layer of the cerebellum and the cerebral cortex when the mice were growing up, as well as in the Purkinje cells of the cerebellum. The variation of expression levels and distribution of ANP32A in the developing brain would imply that ANP32A may play an important role in mammalian brain development, especially in the differentiation and function of neurons in the cerebellum and the cerebral cortex.

A Case of Anomalous Values in Indian Civilization: Meat-Eating Among the Kanya-Kubja Brahmans of Katyayan Gotra

1966 ◽  
Vol 25 (2) ◽  
pp. 229-240 ◽  
Author(s):  
R. S. Khare
Keyword(s):  
Social Situations ◽  
Social Scientists ◽  
Meat Eating ◽  
Philosophical Thought ◽  
The Social ◽  
Social Anthropologist ◽  
And Function ◽  
Meaning And Function ◽  
Different Levels

Indian philosophical thought has always attempted to deal with opposite or binary values. However, when faced with contradictions, social scientists try to analyze the form, meaning and function of opposed values in real social situations. The problem of opposed values becomes difficult and anomalous when the culture, at different levels, not only permits oppositions, but simultaneously sanctions them. The data on meat-eating among the Kanya-Kubja brahmans of Katyayan gotra (primarily an exogamous group composed of several lineages) present this type of problem to the social anthropologist.

Applying Basic Neuroscience to Aphasia Therapy

1995 ◽  
Vol 4 (4) ◽  
pp. 88-93 ◽  
Author(s):  
Kristen A. Keefe
Keyword(s):  
Learning And Memory ◽  
Neural Plasticity ◽  
Behavioral Interventions ◽  
Cortical Reorganization ◽  
Mammalian Brain ◽  
Cortical Injury ◽  
Aphasia Therapy ◽  
Neural Processes ◽  
Adult Mammalian Brain ◽  
Environmental Demands

Advances in basic neuroscience have increased our knowledge about the neural processes underlying learning and memory and the cortical reorganization that occurs in response to environmental demands and cortical injury. This article provides a selective review of published studies conducted in animals that examine functional and structural substrates of neural plasticity in the adult mammalian brain, and discusses the implications of this knowledge for aphasia therapy. The processes and constraints identified in the studies reviewed can be used to refine and justify current aphasia therapies, as well as to design additional behavioral interventions.

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