The On Blood Brain Barrier

The phospholipid bilayer that makes up the cell membrane is largely made up of a mixture of lipids and proteins. The lipids give the structure the right level of flexibility, while the proteins help to watch and control the cell’s “chemical climate” and also with molecule movement across the bilayer. This means that the proteins, especially the ones that bridge the whole membrane, can allow passage of say electrolytes and non-lipid substances.

There are many expecting mothers who suffer from serious mental illnesses like schizophrenia, bipolar disorder, or borderline personality disorder that requires they must take antipsychotic drugs to remain stable. There are different types of antipsychotics like typical and atypical. Typical antipsychotics are classified as the first generation of antipyschotics. The atypical antipsychotics, the second generation, are reported to be safer than the typical antipsychotics because they are the newer form of antipsychotic medication. Even though they are reported to be safer, they still have severe side effects on the individual consuming it, like tardive dyskinesia, which are uncontrollable movements of the mouth (McCauley et al., 2009). Some drugs can affect the fetus by transferring to the blood-brain barrier. The blood-brain barrier is a permeable barrier that allows some chemicals to pass through. It separates the circulating blood from the brain extracellular fluid in the central nervous system. The blood-brain barrier also transports molecules to the brain that are essential to function properly, like glucose and amino acids. Since capillary endothelial cells, which line the whole circulatory system, form the blood-brain barrier the medication could be transported to the fetus. From

amount of the fluid that protects the brain and spinal cord. The fluid is tested to

capacity to repair itself. Many drugs cannot cross the blood-brain barrier to act on the

Alzheimer's is a neurodegenerative disorder that affects the neurons within the brain, causing memory loss as well as language, and behavioral disturbances. An Alzheimer's brain contains Amyloid plaques that form toxic proteins which are called amyloid beta. The amyloid plaques start to spread throughout the brain causing tangles to form in the brain. The tangles are a form of twisted threads of protein. In compartment to a “normal” brain with an Alzheimer's brain, that Alzheimer's brain is remarkably smaller in size and contains fluid flied spaces.

The blood-brain barrier (BBB) is a multifunctional interface separating the bloodstream from the brain interior. This barrier is crucial for maintaining brain homeostasis and allowing proper neuronal function, as well as for protecting the CNS from potentially harmful agents in the blood. The onset of BBB properties takes place during embryonic development as a microenvironment of neural stem cells, pericytes, and neurons provide developmental cues for induction of tight junctions and regulation of molecular permeability in developing endothelial cells. In adults, blood-brain barrier maintenance is a result of composite interactions between brain endothelial cells and resident neural cell types including astrocytes, pericytes, and neurons.

When a brain artery is blocked, an ischemic stroke occurs and electrical activity is compromised. The areas of injury in the brain are the core ischemic zone (the main area that blood flow is at its lowest) and the ischemic penumbra (surrounding area). Neurons carry necessary oxygen and glucose to the brain. When the brain is deprived of oxygen and glucose, brain cells, glial cells, and vascular cells are affected depending on the amount of blood supply and duration of blocked blood supply to the area. Cells in the penumbra have a chance of restoration if blood flow from surrounding arteries compensate. For areas absent of blood flow, hypoxic injury occurs and cells go through necrosis while surviving cells may

The term Glia is Greek in origin and means glue, this symbolic relationship between Glia’s name, and its function becomes ever more apparent when we learn that Glia cells secure the brain’s neurons together and protects them. Glial cells are crucial to the body’s ability to maintain homeostasis and contribute to almost all forms of homeostasis, such as regulating capillary flow, maintaining the blood brain barrier, extracellular respiration, and can even provide lactate to the neurons for energy. This essay will specifically be examining the Glia cells located within the Central Nervous System.

Studies completed over the last 15 years have shown that glutamate is the powerful neurotoxin in stroke, capable of killing neurons in the central nervous system when its extracellular concentration is sufficiently high. Many experiments show that glutamate plays a key role in ischemic brain damage and that drugs which decrease the accumulation of glutamate or block its postsynaptic effects may be rational therapy for stroke. Glutamate also causes an influx of sodium ions into neurons, correctly anticipating many of the more sophisticated neurophysiological experiments of the past two decades. In a study of spreading depression of cerebral cortical activity, it was also suggested that extracellular Glu could increase the sodium permeability of neurons. Glutamate has been localized to excitatory terminals in the hippocampus.

The brain is a powerful workhorse and is responsible for the communication system of billions of neurons. These neurons deliver and receive message to different structures in the brain. This communication system is comprised of the brain, spinal cord and the peripheral nervous system (Steven & Smith, 2012). The message is sent in the form of electrical and chemical signals. Cells receive and pass on message to other neurons. This communication process is made up of neurotransmitters, transporters and receptors. Neurotransmitters are considered to be the brains chemical messenger while the receptors are the brain chemical receiver and transporters are

Cell membranes are surrounded by a phospholipid bilayer that provides a semipermeable barrier for cells, separating the cytosol from the extracellular environment. Phospholipids are ampithatic, meaning that they have a hydrophilic head and hydrophobic tail, which causes the heads to face outwards towards the water and the tails inwards, creating the bilayer [figure 1]. Small hydrophobic molecules such as O2 and CO2 and small uncharged polar molecules such as H2O and ethanol can diffuse through this bilayer, however larger molecules and ions cannot, and thus require proteins, which are polymers of amino acids joined together by strong peptide bonds. These proteins feature throughout the membrane, and account for around 50% of its mass [http://www.ncbi.nlm.nih.gov/books/NBK9898/] . Not only are proteins required for transport of molecules through the membrane, but they also transport signals and are necessary for the cell support; throughout this essay I will focus on the pivotal role they play with regards to the transport of these molecules and signals, and what occurs when these functions are inhibited.

Every year around over six hundred thousand patients in the US go through chemo. Chemotherapy is a procedure that destroys cancer cells in patients who are suffering with cancer.Usually, when one thinks about a patient going through chemo their first thoughts might be “bald, pale or sickly” never does the term “chemo brain” come up through a typical conversation.

In early-E sensitive stages of brain development, neurons maintain GSH in the absence of mature astrocytes or oligodendroglia that is generally GSH rich. Compared to other transporter subtypes such as GLAST and GLT1, EAAC1 expression precedes during early stages of brain development and is especially enriched in cortex [55, 56]. It is also expressed in mature oligodendroglia and mature astrocyte but these cells are mostly not present in the early second trimester equivalent brain [57-59]. Cys-related control of GSH in fetal neurons is an unexplored area. However, the possibility of such a setting in adult brain has been suggested [60]. The present findings combined with low Cys transport activity displayed by other EAATs clearly show an

     The blood brain barrier protects brain cells from harmful substances, as well as, pathogens, by preventing passage of many substances from blood into brain tissue.

The BBB evolved as an extremely tight barrier to protect the brain from potentially toxic compounds. Though it is an indispensable part of the Central Nervous System, its tightness makes delivering therapeutic drugs to the brain very difficult.