Developmental Origins Of Resident Central Nervous System Microglia Part 1

2164 words - 9 pages

Microglia are hematopoietic-derived innate immune cells that constantly survey the environment and regulate the development of the central nervous system (CNS). These cells have dynamic cellular processes that make contact with synapses and engulf cellular debris from dying neurons. The origin of microglia has been a controversial topic for decades. Recently, it was demonstrated that microglia originate in the yolk sac (YS) from YS-derived macrophages during primitive hematopoiesis and subsequently populate the embryonic brain (Ginhoux et al., 2010). However, it remains unclear whether this cohort accounts for the total resident CNS microglia population following embryonic development because of the transient spatiotemporal nature of hematopoietic sites and circulation of microglial progenitors through the developing vasculature system. Furthermore, it is also not known whether progenitors from preceding hematopoietic sites are required to seed impending hematopoietic sites for the generation of hematopoietic stem cells (HSCs). In this review, we will provide a brief context on hematopoietic development at major hematopoietic sites followed by a discussion on the current evidence regarding the origin(s) of resident CNS microglia.
Hematopoiesis is the development of the blood system that is characterized by a spatiotemporal sequence of transient events. Each transient event is thought to follow the monophyletic theory of hematopoiesis whereby pluripotent stem cells undergo asymmetric division to either self-renew or generate lineage-restricted committed progenitor cells. These committed progenitors generate immature blood cells specific for the lymphoid, erythroid, and myeloid lineages (Chaplin et al., 2003, Laiosa et al., 2006). The lymphoid lineage generates T- and B-cells from a common lymphoid progenitor (CLP) that reside in the thymus. The erythroid and myeloid lineages generate red blood cells and platelets, mast cells, neutrophils, monocytes, macrophages, and dendritic cells, respectively, from a common myeloid progenitor (CMP). Progenitors fated to each hematopoietic lineage is generated at different times in different tissues, hence the spatiotemporal nature of hematopoiesis. Two caveats arise in studying hematopoiesis: 1) the primary site (e.g. yolk sac, aorta-gonad-mesenephros, fetal liver, bone marrow) to generate HSCs shifts during embryonic development and 2) the migration of HSCs through the developing vasculature following the onset of circulation.
Microglia, as well as CNS-associated macrophages, are tissue-resident macrophages in the CNS derived from mononuclear phagocytes. Mononuclear phagocytes originate from HSCs through differentiation pathways based on endogenous and environmental cues. These mononuclear cells were believed to be derived from leukocyte HSCs because bone marrow-derived monocytes (leukocytes) could differentiate into tissue-resident macrophages. Current evidence suggests that there is...

Find Another Essay On Developmental Origins of Resident Central Nervous System Microglia Part 1

Central nervous system (CNS) Perifial Nervous system (PNS)

821 words - 3 pages The nervous system consists of neurons and axons. Neurons are responsible for receiving and transmitting electrochemical signals. Axons are long fibers of the neuron that carryout efferent nerves (messages). The neuron sends an electrical message from its body by way of the axon. Each neuron has an axon (Pinel, 2008).The peripheral nervous system (PNS) and the central nervous system (CNS) are similar because they both consist of neurons and

The Nervous System of the Human Body

785 words - 3 pages The Nervous System of the Human Body The nervous system of the human body is responsible for sending, receiving and processing nerve impulses. It controls the actions and sensations of all the parts of the human body as well as your thoughts, emotions and memories. The nervous system is a "speedy electrochemical communication system of all the nerve cells of the peripheral and central nervous system". The most basic and important part in

A Comparison of Two Nervous System Disorders

1422 words - 6 pages treatments and/or management of each disease. Background of Multiple Sclerosis: Multiple Sclerosis (MS) can be defined as a degenerative disease that attacks the brain and spinal cord: two key components of the central nervous system. Unfortunately, this disease affects a large number of individuals. According to a study completed by Rumrill, every 1 in 750 individuals will end up having multiple sclerosis at any given point in time.1 This high

Growth Impairment of the Fetal Nervous System by Nicotinic Stimulation

1203 words - 5 pages . Although concurrent exposure of the fetus to hypoxia and ischemia are major contributors to the developmental effects of smoking in man, or of injected nicotine in animals, recent studies using slow infusions of nicotine strongly suggest that nicotine affects fetal and neonatal development. Due to the action of nicotine via neurotransmitter receptors in the nervous system) the sensitivity of the developing brain is displayed in the disruption of

Nerve Regeneration in the Peripheral Nervous System (PNS) of mammals

643 words - 3 pages INTRODUCTION Nerve Regeneration in the Peripheral Nervous System (PNS) of mammals PNS neurons in mammals have a capacity to regenerate and re innervate the target. However functional recovery varies, depending on the type and location of injury, age of the neurons and other factors, but the recovery is never complete. An overview of the regenerative response Following an injury, in the distal nerve stump a series of degenerative

The Origins of the Stanislavski System

1836 words - 7 pages The origins of the Stanislavski System are in naturalism, positivism, Marxism, photography, Darwin, electricity, and realism. There is no one technique of acting and before Stanislavski there was no system at all. He created a system of training wherein actors would research the situation created by the script, break down the text according to their character's motivations and recall their own experiences, thereby causing actions and reactions

Monetary Policy of a Central Banking System

1594 words - 6 pages I. INTRODUCTION Monetary Policy is how the Central Bank influences the path it wants the economy to follow. It does this through the control of money supply using the short term interest rate as the primary instrument to control inflation and economic growth. The objectives of most Central banks is to sustain low unemployment and relatively stable prices however price stability is the main, medium and longer run goal of monetary policy. An

Globalisation of the Media Part 1 - Ownership

2339 words - 9 pages Essay #1 - Media OwnershipMass media is ideally what its name suggests, a voice for the masses. But, as the line between the business and editorial side of journalism grows hazier, it is instead becoming a tool for the minority of corporate and political elites. Increasingly concentrated ownership has created an oligopoly in the media industry. The result is homogenized and watered down content heavily influenced by owner and advertiser

The ABC'S of 'Hacking' Part 1

1832 words - 7 pages lookup and find out the publicly available IP addresses allocated to that company. Those different address ranges are the point of your attack.If you are confused with all the technical jargon I just wrote down I will explain each part now. To sniff is have a program sitting on your computer look beyond your computer, possibly your own home network and analyze how your target is surfing the internet, transferring information in his own network and

Patalogy of the Central Nevrvous System: Multiple Sclerosis

1367 words - 5 pages Multiple Sclerosis: Pathology of the Central Nervous System Multiple Sclerosis is an autoimmune disease that commonly found in individuals between the ages of 20 and 40. While men with MS tend to have a faster progressing disease, women are more likely than men to develop it. MS comes in many forms due to the extent of the damage and the amount of lesions, along with how quickly it progresses. All of this collectively forms the MS community

Discuss the roles of development, learning and evolution in the construction of the nervous system.

2724 words - 11 pages expressed in its growth cone. The proficiency of a neuron to read such gradients has been shown to be equal irrespective of the point of entry, and the mechanism is even viable following misrouting.Each of the developmental processes above is largely activity independent and leads to the formation of the basic neural system, that that is prescribed in the genes. However, the circuitry as established so far is not definitive as the nervous system is

Similar Essays

Developmental Origins Of Resident Central Nervous System Microgila Part 2

2851 words - 12 pages microglial precursors to ramified, mature microglia (Zusso et al., 2012). Proper microglial migration and brain infiltration also depend on the presence of tyrosine kinase receptor for the macrophage growth factor colony stimulating factor-1, Csfr1 (Erblich et al., 2011). Resident CNS microglia have minimal communication with the peripheral immune system after the formation of the blood brain barrier. Heterochronic parabiotic experiments using

Central Nervous System Cancers Essay

1804 words - 7 pages Central nervous system (CNS) cancers are the second most common cancer in children in the United States, representing just over 20% of all malignancies during childhood.1 In 2010, there were 4,030 new cases of pediatric brain and other CNS tumors in children between the ages of 0-19, including 2,880 who were younger than 15 years.2 Incidence rates are slightly higher in males when compared to females, and slightly higher among white children

Central Nervous System – Cerebellar System

1631 words - 7 pages CENTRAL NERVOUS SYSTEM – CEREBELLAR SYSTEM Though many books include cerebellar examination as part of the motor exam, it is discussed as a separate category in view of its importance. As children with cerebellar diseases are not frequently seen in routine clinical practice, candidates tend to neglect this system in their preparation and hence find it difficult in the exam. Cerebellar assessment involves examination of the gait and co

Central Nervous System Stimulant: Ritalin Essay

1844 words - 7 pages Ritalin is a brand name for methylphenidate. Ritalin is a mild central nervous system stimulant that doctors prescribe to treat several disorders. The most common use of Ritalin is for the treatment of Attention Deficit Disorder (ADD) and Attention-Deficit Hyperactivity disorder (ADHD). Another known use of Ritalin is in the treatment of Narcolepsy. A doctor might also prescribe it to treat depression. Ritalin and other drugs in the