Describe The Role Of Neurons In The Brain

Glutamate-receptor-interacting protein (GRIP) is the interacting protein which is associated with AMPAR protein receptor in the postsynaptic cell. Amount of GRIP is associated with AMPAR receptors can lead to the prediction of activity in the presynaptic cell. AMPAR receptor change shape to be ready to receive neurotransmitter when GRIP bind. The presynaptic cell contains vesicle which neurotransmitters are accommodated. When calcium enters the presynaptic cell by calcium channel, vesicles dock to the presynaptic cell to become ready to release neurotransmitters to the synaptic gap. Neurotransmitters are released in a packet called quanta. AMPAR receptor has to change its shape by GRIP to receive the release of quanta in the synaptic

Once a presynaptic neuron is passive, an electrical current is spread along the length of the axon (Schiff, 2012). This is known as action potential (Pinel, 2011). Action potential happens once an abundant amount of depolarisation reaches the limit through the entry of sodium, by means of voltage gated sodium channels

Glutamate receptors (NMDAR and AMPAR) of the postsynaptic membrane are the initial triggers for LTP induction. NMDARs require the binding of glutamate and the co-agonist glycine, as well as depolarization of the postsynaptic membrane, to become activated and permeate Na+, K+ and Ca2+. Most of AMPARs contain GluA2 and permeate Na+ and K+. Glutamate binding to the AMPARs causes a Na+ influx into the postsynaptic neuron. This depolarization leads to Mg2+ block releasing from NMDARs. Glutamate binding and the Mg2+ removal opens NMDARs, Ca2+ and Na+ then flow into the postsynaptic neuron. Through repeated activation of the postsynaptic neuron, sufficient Ca2+ comes in and triggers a series of molecular events required for LTP

Here is an explanation of the process of muscle contraction and subsequent relaxation from the point where the action potential reaches the junction between the nerve cells and the muscle-fibre. I will introduce the role of calcium, sodium and ATP, as well as taking a look at some of the proteins and enzymes utilised in this process. Action potential travels along the plasma membrane of a neuron. When the action potential reaches the synaptic end bulb it stimulates voltage-gated channels which open to allow Ca2+ to flow into the synaptic end bulb from the extra-cellular fluid, down it's electrochemical gradient. These positively charged calcium ions stimulate the synaptic vesicles into releasing acetylcholine (ACh) into the synaptic cleft

Located inside a specialized cell called a neuron, synaptic vesicles secrete a neurotransmitter when signaled to do so. There are many different neurotransmitters in the human body and the release of too much or too little of a certain one can throw off the mood, health, and alertness of a person. For this reason, balanced release of neurotransmitters is vitally important to the health and well-being of every person alive.

Neurotransmitters are chemicals made by neurons and used by them to transmit signals to the other neurons or non-neuronal cells (e.g., skeletal muscle; myocardium, pineal glandular cells) that they innervate. The neurotransmitters produce their effects by being released into synapses when their neuron of origin fires (i.e., becomes depolarized) and then attaching to receptors in the membrane of the post-synaptic cells. This causes changes in the fluxes of particular ions across that membrane, making cells more likely to become depolarized, if the neurotransmitter happens to be excitatory, or less likely if it is inhibitory.

At the molecular level of explanation these processes are dependent on the interplay between glutamate receptors, Ca2+ channels, the increase of intracellular Ca2+ levels, Ca2+-dependent proteins like Akt, ERK, mTOR and neurotrophins such as brain derived neurotrophic factor (BDNF) (24, 25).

The brain is a unique organ, it allows us as humans, for example to imagine, speak and perform a lot more complex functions. To function well as a complex organ, the brain has a lot of cells. The brain consists of neurones and glia cells. Neurones observe changes from the environment, communicate these changes to other neurones and issue commands to the body to react on these changes. Glia cells give the neurones among other things protection and support. Neurones are really small cells composed of two parts: the soma, which contain the cell nucleus and neurites, which are projections from the soma. There are two different types of neurites, the axon and the dendrite. Dendrites receive signals to transfer to the neurones and axons carry the output of the neurones. Figure 1 gives a schematic overview of a neuron and shows the dendrites, cell body and axon. This essay will discuss the structure of neurones and the different types of neurones further in detail. It will start with the structure of a typical structure of a neuron and then the different types of neurones, the sensory-, motor- and interneurones. (Bear, M.F. et al. (2007))

As soon as the electrical signal reaches the end of the axon, mechanism of chemical alteration initiates. First, calcium ion spurt into the axon terminal, leading to the release of neurotransmitters “molecules released neurons which carries information to the adjacent cell”. Next, inside the axon terminal, neurotransmitter molecules are stored inside a membrane sac called vesicle. Finally, the neurotransmitter molecule is then discharged in synapse space to be delivered to post synaptic neuron.

How AP firing of living neurons alters the electrochemical properties of CPs to release Glu will be investigated. The AP firing has a short duration (~5 ms) with a magnitude (amplitude) of 100 mV. Whole cell patch clamp electrophysiology techniques will be used. Neurons in contact with CP will be induced to fire action potential, triggering Glu release through current injections of 20-800 pA over 20-1000 ms (36, 73, 78). While one AP lasts ~5 ms, current injection to sustain AP firing can be routinely performed for 20 – 1000 ms to induce multiple AP if required (73). Fig. 7 shows the setup that has been designed to be compatible with the patch clamp apparatus and will be used in the experiment. As media flows through the setup, the media leaving will be quantified for Glu with an HPLC method. If AP firing is insufficient to cause Glu release, amplification methods will be applied to boost the triggering

Synapses are the basic structures underlying neurotransmission and brain function. Synapses are composed of a presynaptic neuron and a postsynoptic neuron which are separated by a synoptic cleft. Neurotransmitters are synthesized and packages into synaptic vesicles in the presynaptic neural terminal. In response to a nerve impulse, the vesicles are extruded into the synaptic cleft; approximately 1,000 molecules of neurotransmitter per terminal. The neurotransmitters then bind

Neurotransmitters are endogenous chemical compounds that transmit neural signals from one neuron to another. Many neurotransmitters are amino acids, such as glutamate, glycine and GABA, or biogenic amines, such as dopamine and serotonin, or even peptides and proteins, such as somatostatin and substance P {Snyder 1979}. Binding of neurotransmitters may either inhibit or excite the postsynaptic neurons. Among the numerous neurotransmitters, glutamate is the major excitatory amino acid neurotransmitter in mammalian neural systems {Cotman 1986}. The first genetically encoded neurotransmitter for glutamate was reported in 2005 {Okumoto, 2005 #292}. Upon binding to glutamate, the indicator converts the

Neurotransmitters are chemical messengers involved in signalling and transmission of nerve impulses across the synapses. They pass into the synaptic cleft through the membranes of the synapses and travel to the opposite membrane initiating an electrical stimulus. Glutamic acid is a neurotransmitter that plays a principal role in neural activation within the brain. It is also responsible for the taste sensation referred to as ‘umami’ that is associated with certain

The body uses chemicals known as neurotransmitters, and according to Dr. C. George Boeree, they are chemicals which allow the transmission of signals from one neuron to the next across synapses. Additionally, neurotransmitters are also responsible for muscle stimulation that are produced by adrenal glands and pituitary glands. One of the first, and most abundant, neurotransmitters to be discovered is acetylcholine, often abbreviated ACh (Cherry). This was first discovered by a German biologist, Otto Loewi, in 1921 who later won a Nobel Prize for his findings (Boeree). Acetylcholine is present in both inhibitory functions as well as excitatory functions, which means that it can both speed up and slow down nerve signals (“Acetylcholine”). Its role in the central nervous system is excitatory, and plays a role in arousal, learning, memory, and neuroplasticity. Other functions include engaging functions such as waking, help sustain focus, maintain rapid eye movement

In the brain there is an excitory and inhibitory input of neurotransmitters. GABA is the main inhibitory input of neurotransmitters and glutamate is the main excitory input of neurotransmitters. Glutamate transmits chemical signals from neuron to neuron. It is critical for learning and remembering. [1] Glutamate, as it is lethal in high concentrations to nerve cells, is stored in neurons as glutamine in order to keep the neurons healthy and to prevent the stimulation of seizures. [2] Glutamate is synthesised one of two ways, it can either be converted from glutamine to glutamate with the assistance of the enzyme glutaminase, or by transaminating 2-oxoglutarate. [3]