Synaptic Activity Is Vital For The Passage Of Information Throughout The Nervous System

The cerebral cortex directs functions like speech, behavior, reactions, movement, thinking, and learning. In fact, some research suggests that bipolar disorder originates with problems with the thalamus, which links sensory input to good and bad feelings. The hippocampus also affects depression. It, like the amygdala, is part of the limbic system. It is vital in processing long-term memory. This section of the brain registers recurring fear. In people with clinical depression, the hippocampus is much smaller. Research suggests, even, that ongoing exposure to stress impairs the growth of nerve cells in this part of the brain. One of the most important jobs of the brain is to process senses, through neurons. Neurotransmitters are specific substances that help relay information to the brain. Scientists have identified many neurotransmitters that affect depression. A lack or excess of the neurotransmitters acetylcholine, serotonin, norepinephrine, dopamine, glutamate, lithium carbonate and gamma-aminobutyric acid are thought to contribute to depression. Acetylcholine is involved in learning and enhances memory. Serotonin helps regulate sleep, appetite, and mood, and inhibits pain. Research shows the idea that many depressed people have reduced levels of serotonin. Low levels of a byproduct of serotonin have been linked to a high risk for suicide. Norepinephrine is a neurotransmitter which constricts blood vessels and raises blood pressure. An excess in

To send a message, a neuron will send a ripple of electrical energy down its axon. This ripple is called "action potential." The way it works is by changing the chemical makeup of the axon's negatively charged interior. Positively charged sodium ions move into the cell and negatively charged potassium ions move out, then the ions move to their original positions. This produces a wave of positively charged

Neurons communicate with each other through an electrochemical process in three steps (Stufflebeam, 2008). An electrical impulse will travel down the axon to axon terminals. This causes the vesicles to open and neurotransmitter molecules are released into the synaptic gap. Neurotransmitter molecules then cross the synaptic gap and enters the receptor sites located on the dendrites of the receiving neuron. The information is carried along axons and dendrites because of changes in electrical properties which we call action potential. An action potential is initiated when a messenger attaches itself to a receptor. This occurrence causes an electrical signal to be triggered and is generated through the neuron. Once the signal reaches the end of an axon, which is at the end of a neuron, a neurotransmitter molecule will return to the synaptic gap where they are received by the sending neuron and the process is repeated or are destroyed by enzymes (Griggs, 2014, p. 41-45).

three groups.Monoamine oxidase inhibitor (MAOI) medicines block the monoamine oxidase enzyme (MAO) from destroying monoamine neurotransmitters, which allows them to accumulate, alleviating depression. Serotonin selective reuptake inhibitor (SSRI) medications block the serotonin reuptake pump, allowing the serotonin neurotransmitter to remain and accumulate in the receptor for longer. Speaking of serotonin specifically, depression has been related to a deficiency of the 5-hydroxytryptamine (serotonin) neurotransmitter as evidenced by the concentrations of the

It plays a significant role in many neurological functions, including brain plasticity (4), learning and memory (5), and induction of pain (6). Poor or excess release of glutamate can cause serious neurodevelopmental and neurodegenerative disorders such as autism (7-9), epilepsy (7, 10-13), schizophrenia (14), Alzheimer’s disease (14-17) and Parkinson’s disease (18, 19). Physiologically, glutamate is released from pre-synaptic vesicles into neuronal synapses in response to action potential. The concentration of glutamate within the vesicles is reported to be ~100 mmol/L (20). The action potential firing mechanism primarily involves the movement of cations (Ca2+, Na+ and K+) across the neuronal membrane. Two voltage-gated ion-channels located in the axon permit active transport of K+ and Na+, into and out of the cells (20). This ion exchange creates a potential difference of -70 mV (resting potential) through the neuronal membrane. Sudden depolarisation or action potential occurs when potential drops, allowing Na+ to flood into the cells. Action potential is terminated to restore the resting potential of the membrane. Ca2+ channels open to allow the transport of Ca2+ (2). This ultimately causes glutamate to be released from its vesicle into the area between presynaptic membrane and postsynaptic membrane of the subsequent neuron. Through this electrochemical signal

The synapse has two neurons: pre-synaptic that sends and post-synaptic that receives information. When an action potential arrives at a synapse, pores in the cell membrane begin to open such that calcium ions can flow into the pre-synaptic terminal, causing chemical neurotransmitters to be discharged into the synaptic cleft. The neurotransmitter spread over the synaptic cleft and interacts with receptors in the post-synaptic membrane. These receptors are ion channels and will open up to let ions flow into the post-synaptic terminal after they interact with the neurotransmitter. Neurotransmission can be either excitatory or inhibitory, which either increases the likelihood of the post-synaptic neuron triggering an action potential or decreases that of an action potential being generated. The production of action potentials follows the all-or-nothing principle because they either occur completely or do not happen at all.

Depression is a product of diminished levels of serotonin in the brain, in which there are selective serotonin reuptake inhibitors (SSRIs) available for patients to can take. The purpose of anti-depressants is to assist with the transportation of serotonin to the brain. The function of SSRIs at the synaptic cleft is to increase serotonin levels. Anti-depressants or SSRIs work to increase serotonin levels at the synapse by blocking serotonin reuptake. Selective serotonin reuptake inhibitors have become the drug of choice for patients with depression. SSRIs produce less side effects then other anti-depressants due to their controlled action to reuptake serotonin. Prozac (a very commonly used SSRI), for example, has developed so widely that it is not only used to treat depression. Even though SSRIs are successful way of handling depression, they do still harvest harmful side

The period of time between when a stimulus occurs and when the body elicits a response is called the latent period or reaction time. These times can vary for different stimuli and from person to person. The BIOPAC student manual states that the most important factor that contributes to reaction times is the mechanism behind synaptic transmission. This involves a presynaptic neuron communicating with a postsynaptic neuron via neurotransmitter release. When neurotransmitters are released, they can cause the postsynaptic neuron to have an increase or decrease in excitability, which then factors into the response of the brain. The changes in the release of neurotransmitters can be acute or chronic, and synaptic transmission itself can be inhibited or facilitated by certain factors.

Serotonin syndrome is a drug-induced syndrome that results in mental, autonomic and neuromuscular changes. A range of toxic symptoms including clonus, hyperreflexia, tremor, agitation, confusion and shivering are results of the increased serotonin concentrations in the central nervous system (Hall and Buckley, 2003). Serotonin (5-hydroxytryptamine, 5-HT) is a neurotransmitter produced from the decarboxylation and hydroxylation of tryptophan. Serotonin is stored within the vesicles and released into the synaptic cleft when stimulated (Volpi-Abadie et al., 2013). As serotonin influences on mood, sleep, vomiting and pain perception, the serotonin levels are tightly regulated by the reuptake mechanisms, degradation by monoamine oxidase type A and feedback loop (Thanacoody,

The linkage of serotonin to depression has been known for the past five years. From numerous studies, the most concrete evidence of this connection is the decreased concentration of serotonin metabolites like 5-HIAA (5-hydroxyindole acetic acid) in the cerebrospinal fluid and brain tissues of depressed people. If depression, as suggested, is a result of decreased levels of serotonin in the brain, pharmaceutical agents that can reverse this effect should be helpful in treating depressed patients. Therefore, the primary targets of various antidepressant medications are serotonin transports of the brain. Since serotonin is activated when released by neurons into the synapse, antidepressants function at the synapse to enhance serotonin activity. Normally, serotonin's actions in the synapse are terminated by its being taken back into the neuron then releases it at which point "it is either recycled for reuse as a transmitter or broken down into its metabolic by products and transported out of the brain." As a result, antidepressants work to increase serotonin levels at the synapse by blocking serotonin reuptake (2).

Action potentials act as ‘messengers’ to brain in the form of electrical signals. They are generated by depolarization which is a voltage change in the membrane of a neuron cell. An action potential is produced in each nerve cell and travels along the axon of the nerve cell. The action potential causes a release of a neurotransmitters to

The synaptic gap or the synaptic cleft is where the axon is sending chemical substances to dendrite. Pre-synaptic neuron is transmitting neurotransmitter and post-synaptic neuron receives neurotransmitter. Neurotransmitter can affect or mental abilities and there are different types of them. Like; Acetylcholine (ACh), Dopamine, Serotonin, Norepinephrine, Gamma-aminobutyric acid (GABA), Glutamate. Acetylcholine helps work the muscles. And also, learning and memory. When the brain not producing ACh the way they should be; this is how Alzheimer’s disease develop. Dopamine plays the role of moods, motivation, learning, and movement. Malfunctions of this neurotransmitter is Parkinson’s disease and schizophrenia. Parkinson’s happens when the brain is undersupplying of dopamine and schizophrenia is overproducing. Serotonin have an impact on mood, appetite, regulate sleep, and arousal. When the brain is undersupply of serotonin, mental disease like, depression are developed. This is why in antidepressant, it helps raise the levels of serotonin. Norepinephine have the ability to regulate alertness and arousal. Similar to serotonin, depression occur when there is a low amount levels of norepinephine. GABA is a very major neurotransmitter, it controls and regulate sleep, relaxation and anxiety. Seizures, tremors, and insomnia involves when the brain is low with GABA. Glutamate have similar ability to the

The action potential is connected to the end of the axon, which is a tube that extends from the soma and branches out. The action potential starts where it ends at the end of the axon and travels down to the terminal button, which contains synaptic vesicles. The synaptic vesicles store neurotransmitters once they are synthesized. Once that is done, the neurotransmitters releases from the presynaptic neuron, this is the neuron that transmits the message, and sends a message to the postsynaptic neuron. After the action potential gets to the terminal button, voltage dependent calcium goes to the presynaptic membrane and opens while calcium comes into the cell. The calcium hen connects to the synaptic vesicles and causes the vesicles to break and

The chemical communication that occurs in the synapses is made possible with neurotransmitters, which are housed by synaptic vesicles and

Synaptic transmissions, otherwise referred to as neurotransmissions, are important to look at when investigating how physiological changes have an effect psychologically as changes have an affect on behaviour. Neurons are nerve cells that send electrochemical messages to the brain in the response from a stimuli and neurotransmitters transfer information from the neurons by diffusing across synapses. Synaptic transmission is the process by which neurons transfer the information; the neurotransmitters are released by neurons and bind to the receptors of postsynaptic neurons.