Neuroanatomy and Neuroscience at a Glance

Roger A. Barker, Francesca Cicchetti, Emma S. J. Robinson

• Publisher: Wiley-Blackwell
• Year: 2017
• Print ISBN: 9781119168416
• eBook ISBN: 9781119168423
• Edition: 5
• Topic: Biological Sciences
• Subtopic: Neuroscience
• Index: Biological Sciences

British Medical Association Book Award Winner - Student Textbook of the Year 2018

Everything you need to know about Neuroanatomy and Neuroscience … at a Glance!

Neuroanatomy and Neuroscience at a Glance is a highly illustrated, quick reference guide to the anatomy, biochemistry, physiology and pharmacology of the human nervous system. Each chapter features a summary of the anatomical structure and function of a specific component of the central nervous system, a section on applied neurobiology outlining how to approach a patient with neurological or psychiatric problems aligned to the chapter topic, standard diagnostic procedures for most common scenarios, as well as an overview of treatment and management options.

This fully updated and expanded new edition includes: 

• Dozens of full-page, colour illustrations and neurological scans
• Expanded coverage of techniques to study the nervous system
• More practical information on the neurological exam
• New content on neuropharmacology and drug therapies
• Bullet points and bold terms throughout assist with revision and review of the topic

Neuroanatomy and Neuroscience at a Glance is the ideal companion for students embarking on a neuroanatomy or neuroscience course, and is an excellent reference tool for those in clinical training.

An updated companion website with new clinical cases, multiple choice self-assessment questions, revision slides, and downloadable illustrations and flashcards is available at www.ataglanceseries.com/neuroscience

 

Part 1
Anatomical and functional organization

Chapters

1. 1 Development of the nervous system
2. 2 Organization of the nervous system
3. 3 Autonomic nervous system
4. 4 Enteric nervous system
5. 5 Meninges and cerebrospinal fluid
6. 6 Blood supply to the central nervous system
7. 7 Cranial nerves
8. 8 Anatomy of the brainstem
9. 9 Organization of the spinal cord
10. 10 Organization of the cerebral cortex and thalamus
11. 11 Hypothalamus

1
Development of the nervous system

The first signs of nervous system development occur in the third week of gestation, under the influence of secreted factors from the notochord, with the formation of a neural plate along the dorsal aspect of the embryo. This plate broadens, folds (forming the neural groove) and fuses to form the neural tube, which ultimately gives rise to the brain at its rostral end (i.e. towards the head) and the spinal cord caudally (i.e. towards the feet/tail). The fusion begins approximately halfway along the neural groove at the level of the fourth somite and continues caudally and rostrally with the closure of the posterior/caudal and anterior/rostral neuropore during the fourth week of gestation.

Development of the spinal cord

The process of neural tube fusion isolates a group of cells termed the neural crest.

• The neural crest gives rise to a range of cells including the dorsal root ganglia (DRG) and peripheral components of the autonomic nervous system (ANS; see Chapter 3).
• The DRG contain the sensory cell bodies which send their developing axons into the evolving spinal cord and skin.
• These growing neuronal processes or neurites have an advancing growth cone that finds its appropriate target in the periphery and central nervous system (CNS), using a number of cues including cell adhesion molecules and diffusible neurotrophic factors (see Chapter 47).

The neural tube surrounds the neural canal, which forms the central canal of the fully developed spinal cord.

• The tube itself contains the neuroblasts (ependymal layer), which divide and migrate out to the mantle layer, where they differentiate into neurones to form the grey matter of the spinal cord (see Chapter 2).
• The developing processes from the neuroblasts/neurones grow out into the marginal layer, which therefore ultimately forms the white matter of the spinal cord.
• The dividing neuroblasts segregate into two discrete populations, the alar and basal plates, which in turn create the dorsal and ventral horns of the spinal cord while a small lateral horn of visceral efferent neurones (part of the ANS) develops at their interface in the thoracic and upper lumbar cord (see Chapter 3).
• This dorsoventral patterning relies, at least in part, on factors secreted dorsally (bone morphogenic proteins; BMPs) or ventrally from the notochord (sonic hedgehog; SHH).

Development of the brain

Normal development

The cerebral cortex develops in a ‘radial unit’ manner, with radial glial cell precursor cells from the ventricular zone of the emerging cerebral hemispheres (see Chapter 10). Those neurones born from the ventricular zone (VZ) give rise to the neurones in the deep layers of the cerebral cortex, while the cells from the subventricular zone (SVZ) form the more superficial layers of the cortex. The developing cortex then folds into gyri and sulci and specification into distinct cortical areas. Of late, the genes driving all these processes have been identified as have the physical rules which are employed to allow the growing brain to fold in this way. The radial glial cells that help guide the newborn cells to the developing cortex give rise to the white matter (see Chapter 2).

Adult neurogenesis

Until recently it was believed that no new neurones could be born in the adult mammalian brain. However, it is now clear that neural progenitor cells can be found in the adult CNS, including in humans. These cells are predominantly found in the dentate gyrus of the hippocampus (see Chapter 45) and just next to the lateral ventricles in the subventricular zone (SVZ). They may also exist at other sites of the adult CNS but this is contentious. They respond to a number of signals and appear to give rise to functional neurones in the hippocampus and olfactory bulb, with the latter cells migrating from the SVZ to the olfactory bulb via the rostral migratory stream (RMS). They may therefore fulfil a role in certain forms of memory and possibly in mediating the therapeutic effects of some drugs such as antidepressants (see Chapter 57).

Disorders of central nervous system embryogenesis

• Anencephaly occurs when there is failure of fusion of the anterior rostral neuropore. The cerebral vesicles fail to develop and thus there is no brain formation. The vast majority of fetuses with this abnormality are spontaneously aborted.
• Spina bifida refers to any defect at the lower end of the vertebral column and/or spinal cord. The most common form of spina bifida refers to a failure of fusion of the dorsal parts of the lower vertebrae (spina bifida occulta). This can be associated with defects in the meninges and neural tissue which may herniate through the defect to form a meningocoele and meningomyelocoele, respectively. The most serious form of spina bifida is when nervous tissue is directly exposed as a result of a failure in the proper fusion of the posterior/caudal neuropore. Spina bifida is often associated with hydrocephalus (see Chapter 5). Occasionally, bony defects are found at the base of the skull with the formation of a meningocoele. However, unlike the situation at the lower spinal cord, these can often be repaired without any neurological deficit being accrued.
• Cortical dysplasia refers to a spectrum of defects that are the result of the abnormal migration of developing cortical neurones. These defects are becoming increasingly recognized with improved imaging of the human CNS, and are now known to be an important cause of epilepsy (see Chapter 61).
• Many intrauterine infections (such as rubella), as well as some environmental agents (e.g. radiation), cause major problems in the development of the nervous system. In addition, a large number of rare genetic conditions are associated with defects of CNS development, but these lie beyond the scope of this book.

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Did you know?

The adult human brain continues to make new nerve cells throughout life and that this can be promoted by a whole range of activities including exercising, learning new skills and even socializing.

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2
Organization of the nervous system

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Table of contents

• Cover
• Title page
• Copyright
• Dedication
• Introduction
• Acknowledgements
• List of abbreviations
• Companion website
• Part 1 Anatomical and functional organization
• Part 2 Cells and neurophysiology
• Part 3 Sensory Systems
• Part 4 Motor Systems
• Part 5 Cognition and neural plasticity
• Part 6 Applied neurobiology: the principles of neurology and psychiatry
• Part 7 History of neuroscientific discoveries
• Part 8 Self-assessment case studies
• Answers
• Index
• EULA