scholarly journals Immune System in the Brain: A Modulatory Role on Dendritic Spine Morphophysiology?

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Oscar Kurt Bitzer-Quintero ◽  
Ignacio González-Burgos
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Immune System ◽  
Dendritic Spines ◽  
Cell Lineage ◽  
Myeloid Cell ◽  
Brain Parenchyma ◽  
Immune Mediators ◽  
The Central Nervous System ◽  
The Brain

The central nervous system is closely linked to the immune system at several levels. The brain parenchyma is separated from the periphery by the blood brain barrier, which under normal conditions prevents the entry of mediators such as activated leukocytes, antibodies, complement factors, and cytokines. The myeloid cell lineage plays a crucial role in the development of immune responses at the central level, and it comprises two main subtypes: (1) resident microglia, distributed throughout the brain parenchyma; (2) perivascular macrophages located in the brain capillaries of the basal lamina and the choroid plexus. In addition, astrocytes, oligodendrocytes, endothelial cells, and, to a lesser extent, neurons are implicated in the immune response in the central nervous system. By modulating synaptogenesis, microglia are most specifically involved in restoring neuronal connectivity following injury. These cells release immune mediators, such as cytokines, that modulate synaptic transmission and that alter the morphology of dendritic spines during the inflammatory process following injury. Thus, the expression and release of immune mediators in the brain parenchyma are closely linked to plastic morphophysiological changes in neuronal dendritic spines. Based on these observations, it has been proposed that these immune mediators are also implicated in learning and memory processes.

scholarly journals Standarization of a Protocol of Immunohistochemistry for the Detection of Brain Microglia in Wistar Rats

2017 ◽  
Vol 19 (3) ◽  
pp. 45
Author(s):  
Karol Ramírez Chan DDS, MSc, PhD ◽  
Jaime Jaime Fornaguera-Trías PhD
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Immune System ◽  
Wistar Rats ◽  
Secondary Antibody ◽  
Research Activity ◽  
The Central Nervous System ◽  
Near Future ◽  
The Brain ◽  
Microglia Morphology

Objective: Standardize a protocol of immunohistochemistry that has been widely used in C57BL/6J mice to identify microglia of the central nervous system in Wistar rats.  Materials and Methods: This research activity was carried out in two parts. In the first part, a protocol of immunohistochemistry was implemented to identify microglia in the central nervous system of 6 Wistar rats. A primary antibody with reactivity to rat and a specific secondary antibody to the primary were used. Once the protocol was established in rats' brains, an immunological challenge was produced with the intraperitoneal application of lipopolysaccharide in 2 Wistar rats, in order to evidence the changes in microglia morphology.  Results and Discussion: We demonstrate that without making major modifications to the original protocol, it can also be used to identify microglia in adult Wistar rats. In the near future, this immunostaining protocol will be applied to elucidate the bidirectional interaction between the brain and the immune system, under homeostatic conditions and different physiological and pathological stimuli.

scholarly journals Physiology of Microglia

2011 ◽  
Vol 91 (2) ◽  
pp. 461-553 ◽  
Author(s):  
Helmut Kettenmann ◽  
Uwe-Karsten Hanisch ◽  
Mami Noda ◽  
Alexei Verkhratsky
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Immune Cell ◽  
Brain Parenchyma ◽  
Microglial Cells ◽  
Activation Process ◽  
Normal Brain ◽  
The Central Nervous System ◽  
Cellular Compartments ◽  
The Brain

Microglial cells are the resident macrophages in the central nervous system. These cells of mesodermal/mesenchymal origin migrate into all regions of the central nervous system, disseminate through the brain parenchyma, and acquire a specific ramified morphological phenotype termed “resting microglia.” Recent studies indicate that even in the normal brain, microglia have highly motile processes by which they scan their territorial domains. By a large number of signaling pathways they can communicate with macroglial cells and neurons and with cells of the immune system. Likewise, microglial cells express receptors classically described for brain-specific communication such as neurotransmitter receptors and those first discovered as immune cell-specific such as for cytokines. Microglial cells are considered the most susceptible sensors of brain pathology. Upon any detection of signs for brain lesions or nervous system dysfunction, microglial cells undergo a complex, multistage activation process that converts them into the “activated microglial cell.” This cell form has the capacity to release a large number of substances that can act detrimental or beneficial for the surrounding cells. Activated microglial cells can migrate to the site of injury, proliferate, and phagocytose cells and cellular compartments.

scholarly journals Spinal Neurocysticercosis: A Rare Variant of a Common Parasitic Infection

2016 ◽  
Vol 36 (01) ◽  
pp. 66-70
Author(s):  
Paulo Mesquita Filho ◽  
Nério Azambuja Junior ◽  
José Vanzin ◽  
Rafael Annes ◽  
Daniel Varela ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Central Nervous System ◽  
Nervous System ◽  
Parasitic Infection ◽  
Brain Parenchyma ◽  
Clinical Scenario ◽  
Nerve Roots ◽  
Csf Analysis ◽  
The Central Nervous System ◽  
The Brain

Neurocysticercosis is the most common parasitic infection affecting the central nervous system, usually involving the brain parenchyma, intracranial subarachnoid space, or ventricular system. In rare cases, there is involvement of the spine (vertebral, epidural, subdural, arachnoid, or intramedullary). Even in endemic regions, this variant is rare, with an incidence below 5% of all patients. The diagnosis is made based on the symptoms, which can be very unspecific, imaging and CSF analysis, with biopsy as a possibility. Treatment is usually curative, but important deficits can develop, due to compression of the spinal cord or nerve roots, arachnoiditis, or meningitis. We present the case of a patient who developed this entity, with poor clinical scenario, and review the literature on the topic.

scholarly journals Blood-brain barrier-restricted translocation of Toxoplasma gondii from cortical capillaries

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Gabriela C Olivera ◽  
Emily C Ross ◽  
Christiane Peuckert ◽  
Antonio Barragan
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Toxoplasma Gondii ◽  
Blood Brain Barrier ◽  
Brain Parenchyma ◽  
Brain Barrier ◽  
Blood Brain ◽  
The Central Nervous System ◽  
Cortical Capillaries ◽  
The Brain

The cellular barriers of the central nervous system proficiently protect the brain parenchyma from infectious insults. Yet, the single-celled parasite Toxoplasma gondii commonly causes latent cerebral infection in humans and other vertebrates. Here, we addressed the role of the cerebral vasculature in the passage of T. gondii to the brain parenchyma. Shortly after inoculation in mice, parasites mainly localized to cortical capillaries, in preference over post-capillary venules, cortical arterioles or meningeal and choroidal vessels. Early invasion to the parenchyma (days 1-5) occurred in absence of a measurable increase in blood-brain barrier (BBB) permeability, perivascular leukocyte cuffs or hemorrhage. However, sparse focalized permeability elevations were detected adjacently to replicative parasite foci. Further, T. gondii triggered inflammatory responses in cortical microvessels and endothelium. Pro- and anti-inflammatory treatments of mice with LPS and hydrocortisone, respectively, impacted BBB permeability and parasite loads in the brain parenchyma. Finally, pharmacological inhibition or Cre/loxP conditional knockout of endothelial focal adhesion kinase (FAK), a BBB intercellular junction regulator, facilitated parasite translocation to the brain parenchyma. The data reveal that the initial passage of T. gondii to the central nervous system occurs principally across cortical capillaries. The integrity of the microvascular BBB restricts parasite transit, which conversely is exacerbated by the inflammatory response.

scholarly journals Circulating myeloid cells invade the central nervous system to mediate cachexia during pancreatic cancer

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Kevin G Burfeind ◽  
Xinxia Zhu ◽  
Mason A Norgard ◽  
Peter R Levasseur ◽  
Christian Huisman ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Immune Cell ◽  
Purinergic Receptor ◽  
Myeloid Cells ◽  
Myeloid Cell ◽  
Ductal Adenocarcinoma ◽  
The Central Nervous System ◽  
Velum Interpositum ◽  
The Brain

Weight loss and anorexia are common symptoms in cancer patients that occur prior to initiation of cancer therapy. Inflammation in the brain is a driver of these symptoms, yet cellular sources of neuroinflammation during malignancy are unknown. In a mouse model of pancreatic ductal adenocarcinoma (PDAC), we observed early and robust myeloid cell infiltration into the brain. Infiltrating immune cells were predominately neutrophils, which accumulated at a unique central nervous system entry portal called the velum interpositum, where they expressed CCR2. Pharmacologic CCR2 blockade and genetic deletion of Ccr2 both resulted in significantly decreased brain-infiltrating myeloid cells as well as attenuated cachexia during PDAC. Lastly, intracerebroventricular blockade of the purinergic receptor P2RX7 during PDAC abolished immune cell recruitment to the brain and attenuated anorexia. Our data demonstrate a novel function for the CCR2/CCL2 axis in recruiting neutrophils to the brain, which drives anorexia and muscle catabolism.

scholarly journals Th17 lymphocytes traffic to the central nervous system independently of α4 integrin expression during EAE

2011 ◽  
Vol 208 (12) ◽  
pp. 2465-2476 ◽  
Author(s):  
Veit Rothhammer ◽  
Sylvia Heink ◽  
Franziska Petermann ◽  
Rajneesh Srivastava ◽  
Malte C. Claussen ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Central Nervous System ◽  
T Cells ◽  
Nervous System ◽  
Th17 Cells ◽  
Brain Parenchyma ◽  
Th1 Cells ◽  
Th17 Lymphocytes ◽  
The Central Nervous System ◽  
The Brain

The integrin α4β1 (VLA-4) is used by encephalitogenic T cells to enter the central nervous system (CNS). However, both Th1 and Th17 cells are capable of inducing experimental autoimmune encephalomyelitis (EAE), and the molecular cues mediating the infiltration of Th1 versus Th17 cells into the CNS have not yet been defined. We investigated how blocking of α4 integrins affected trafficking of Th1 and Th17 cells into the CNS during EAE. Although antibody-mediated inhibition of α4 integrins prevented EAE when MOG35-55-specific Th1 cells were adoptively transferred, Th17 cells entered the brain, but not the spinal cord parenchyma, irrespective of α4 blockade. Accordingly, T cell–conditional α4-deficient mice were not resistant to actively induced EAE but showed an ataxic syndrome with predominantly supraspinal infiltrates of IL-23R+CCR6+CD4+ T cells. The entry of α4-deficient Th17 cells into the CNS was abolished by blockade of LFA-1 (αLβ2 integrin). Thus, Th1 cells preferentially infiltrate the spinal cord via an α4 integrin–mediated mechanism, whereas the entry of Th17 cells into the brain parenchyma occurs in the absence of α4 integrins but is dependent on the expression of αLβ2. These observations have implications for the understanding of lesion localization, immunosurveillance, and drug design in multiple sclerosis.

Networks and Teleology

1988 ◽  
Vol 14 ◽  
pp. 159-186
Author(s):  
Edwin Levy
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Immune System ◽  
Functional Network ◽  
The Central Nervous System ◽  
The Brain ◽  
New Hypothesis

In 1973 Niels Kaj Jerne announced an important new hypothesis about the immune system (‘IS’). That suggestion is based on several similarities between IS and the central nervous system. Jerne postulated that IS, like the nervous system, is a network.I am convinced that the description of the immune system as a functional network of lymphocytes and antibody molecules is essential to its understanding, and that the network as a whole functions in a way that is peculiar to and characteristic of the internal interactions of the elements of the immune system itself: it displays what I call eigen-behavior. (Jerne [1973), 59)This proposal has a number of implications, including some philosophical ones. Here I focus on the question whether the network hypothesis and subsequent developments shed any light on the use of teleological concepts in biology. In part one I present some of the background story of network ideas in immunology, including a reverse hypothesis to the effect that IS-Net could serve as a basis for modeling the brain. In part two I locate the teleological implications of IS-Net with respect to current mainstream discussions of teleology.

scholarly journals “A distinct neutrophil population invades the central nervous system during pancreatic cancer”

2019 ◽  
Author(s):  
Kevin G. Burfeind ◽  
Xinxia Zhu ◽  
Mason A. Norgard ◽  
Peter R. Levasseur ◽  
Brennan Olson ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Immune Cells ◽  
Purinergic Receptor ◽  
Myeloid Cell ◽  
Ductal Adenocarcinoma ◽  
The Central Nervous System ◽  
Muscle Catabolism ◽  
Velum Interpositum ◽  
The Brain

AbstractWeight loss, fatigue, and cognitive dysfunction are common symptoms in cancer patients that occur prior to initiation of cancer therapy. Inflammation in the brain is a driver of these symptoms, yet cellular sources of neuroinflammation during malignancy are unknown. In a mouse model of pancreatic ductal adenocarcinoma (PDAC), we observed early and robust myeloid cell infiltration into the brain. Infiltrating immune cells were predominately neutrophils, which accumulated at a unique central nervous system entry portal called the velum interpositum, where they expressed CCR2. CCR2 knockout mice had significantly decreased brain-infiltrating neutrophils as well as attenuated anorexia and muscle catabolism during PDAC, without any changes in neutrophils in other organs. Lastly, intracerebroventricular blockade of the purinergic receptor P2RX7 during PDAC abolished neutrophil recruitment to the brain and attenuated anorexia. Our data demonstrate a novel function for the CCR2/CCL2 axis in recruiting neutrophils to the brain, which drives anorexia and muscle catabolism.

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