|
|
This is only a preview of the paper
Click here to register and get the full text.
Existing members click here to login
|
|
|
If an electrode is placed inside a neuron, when it is at rest, its voltage compared with an electrode placed just outside, a small but consistent voltage difference between the two electrodes is found to be around -70mv and this stage is called Resting Potential. ...
The resting potential lie around -70mV, the neural membranes acts as a barrier to external NA+ and K+ ions but when the polarity of the neuron increase to -55mV, it suddenly opens its sodium channels. The NA+ ions rush into the neuron and tries to force their way into the cell, causing the action potential, as the inside of the neuron it becomes positive, the change in voltage is known as excitatory postsynaptic potential. ... The cell which becomes negative it is called an inhibitory postsynaptic potential. When membrane potential lie around +30, sodium ion channels close then it suddenly drop to around –10mV Potassium moves out of the cell and at -60mV Potassium channels close, the NA+ and K+ pump helps returning the neuron to refractory period. The voltage different is the key to how neuron is able to generate action potentials that cause the release of neurotransmitter from the axon terminals. ... Once formed the action potential then has to be transported down the axon. It actively moves the action potential from axon hillock to synaptic terminal. The action potential is amplified back to its original intensity and consequently the action potential effectively jumps down the axon this process is called salutatory conduction and in this way the action potential can travel large distance without becoming weakened. ... It contains chemical called MPTP, which also highly selective neurontoxin for the substantia nigra. ... A drug called Deprenyl is the first treatment that actually slows down the progression of Parkinson’ s disease and it is now becoming a standard therapy for patient along with L-dopa because it has the benefit of allowing this neurotransmitter to stay in the synapse for longer, thus assisting the action of L-dopa.
Approximate Word count = 1989
Approximate Pages = 8
(250 words per page double spaced)
|
|
|
|
|
|