How Neuroinflammation Occurs through the Central Nervous System

Neuroinflammation is an inflammatory response that occurs when the central nervous system’s (CNS) homeostasis is disrupted. The trigger may be one of a number of inflammatory issues, including those resulting from neurodegenerative disease, toxin exposure, injury, or infection. It’s a pathology commonly found in a number of chronic ailments of the brain, including Alzheimer’s, Parkinson’s, and Huntington disease. It’s also associated with schizophrenia, autism, and depression, though the exact mechanisms are not well understood.

Running between the brain and the spine, the central nervous system (CNS) is a conduit for immune modulated responses, which help keep harmful infections, viruses, and diseases at bay. In understanding the exact dynamics of neuroinflammation it’s important to understand the relationship between microglia and astrocytes. Both are cell types, with microglia an immune cell that resides throughout the CNS. Tasked with brain development and immune surveillance, microglia help ensure tissue homeostasis, as well as a well-regulated immune system.

A primary task of astrocytes is controlling blood flow and the levels at which extracellular neurotransmitters function. The aim is to ensure that each microenvironment is optimized for proper neurological function. Along with endothelial cells, astrocytes also form a physical barrier that separates brain and bloodstream. Junctions controlled by astrocytes manage just what passes through and glial cells (a type of astrocyte) maintain the brain as an “immunologically privileged site,” with immune factors excluded from the brain.

However, peripheral immune response (outside of the CNS) may upset that balance. In particular, peripheral inflammation can trigger neuroinflammatory responses that cross the blood–brain barrier (BBB) and involve the neurons and glial cells. When leaky brain syndrome occurs, the BBB is compromised, with the brain’s sensitive environment disrupted and microglia responsible for immune-mediated inflammation activated. Among the varied symptoms of neurological inflammation are weight gain (as metabolism shifts), diabetes, low energy, and mood and cognitive disorders.

It’s worth noting that there are both negative and positive aspects of neuroinflammation. The duration and intensity of such inflammation determines whether immune signals help support, or act against, the central nervous system. Brief, controlled inflammatory responses, such as immune-to-brain signals following infection, tend to be beneficial. After traumatic CNS injury, such signals help improve learning, axonal regrowth, and the recovery of memory,. On the other hand, excessive and maladaptive inflammatory responses generate reactive oxygen species and proinflammatory cytokine protein, and can result in cognitive impairments and less neuronal plasticity.

One way of categorizing these differences is through differentiating microglia, the cells that regulate the CNS immune system, into a trio of classes: the fully activated state, the semi-activated state, and the resting state. In the resting state, microglia are working as a security guard, simply coordinating immune sentry functioning. When semi-activated, microglia generate trophic factor (a growth factor associated with wound healing) but do not produced free radicals that attack one’s own cells.

To continue the analogy of the security officer, they work to protect neurons without misfiring and taking out healthy bystander neurons. When fully activated, microglia generate free-radicals such as nitric oxide, superoxide, and proinflammatory proteins. In marshaling the entire arsenal of the immune system, they inevitably damage some bystander neurons, which can have a cascading effect if the BBB is crossed. Immune system activation over time can result in abnormal neurotransmission and serotonin deficiencies, as well as elevated neurotoxic substance production.

Source: dralirezaminagar

An Overview of Molecular Genetics

 

Molecular genetics is a biological field that explores the molecular-level structure and functions of genes. Scientists study how they shape an organism’s overall composition. The field involves exploring the differences in DNA molecules and their expressions across diverse organisms. Over time, biomedical research has witnessed a transformation in examining diseases associated with organs, and the characterization of diseases grounded in molecules and cells has evolved.

Regarding heredity, especially in molecular genetics, the information gathered by scientists in the early 20th century strongly supported the notion that chromosomes transport genes. However, the essence of the genes stayed enigmatic, and so did the process through which they wielded their impact. Molecular genetics, which studies the molecular level of gene structure and function, provides solutions to these essential inquiries.

Modern understanding of genetics at the molecular level emerged from the traditional investigation of genetics, rooted in Mendelian principles. In the 1800s, Gregor Mendel was a monk in the Czech Republic. He explored the field of plant genetics through extensive experiments over several decades, becoming a researcher and scientist. Mendel’s findings established the traditional inheritance model, where generations transmit traits through parental transfer.

He also established that each specific transmitted trait does not influence other traits. Instead, traits exhibit dominant and recessive forms, and probability enables the anticipation of inherited characteristics at the individual and population levels. Mendel lacked an understanding of the molecular foundation of inheritance due to the absence of DNA discovery during his lifetime. However, the analysis of Mendelian inheritance laid the foundation for more sophisticated investigations into genetics.

Molecular genetic testing distinguishes a distinct set of markers from conventional clinical laboratory testing. Experiments in molecular genetics isolate and examine the DNA or RNA associated with a particular gene. The technique employed for testing can differ based on the purpose, whether diagnostic testing or carrier screening. The type of specimens gathered for molecular genetic testing can also vary.

Most organisms can undergo genetic alterations by applying externally introduced DNA, employing a process akin to Avery’s approach with bacteria. Altering DNA can move through cellular and nuclear membranes before merging with the chromosomal DNA within the host cell.

Also, with the application of contemporary DNA technology, professionals can extract the segment of chromosomal DNA representing a specific gene, modify its arrangement, and reinsert it into a cell, inducing alterations that unequivocally demonstrate the significant role of DNA in shaping the overall traits of an organism. Due to factors like these, most scientists accept that DNA constitutes the genetic makeup of all living organisms, barring certain viruses.

The outstanding characteristics of nucleic acids that make them suitable for conveying genetic information have captured the interest of numerous researchers. Pioneering biochemists established the foundation by discovering that nucleic acids have elongated molecules, with their structures characterized by repetitive sequences of phosphate and sugar linkages. In RNA, the backbone comprises ribose sugar, while DNA consists of deoxyribose sugar.

Molecular genetics plays a crucial role by connecting mutations to genetic disorders, facilitating the exploration of specific therapies and remedies for a range of genetic conditions. Molecular genetics also helps in understanding the intricacies of infectious and noninfectious diseases, playing a role in the advancement of tropical medicine.