today we're going to learn how after receiving information from the dendrites a neuron transmits the information to the presynaptic terminals during this lecture you may or may not be familiar with some of the terminologies that you will hear therefore i strongly encourage that you read the relevant chapter thoroughly going over it several times if necessary alternatively you may also search for and then watch reference videos on the topic to help you understand the material better during last week's lecture you have been introduced to the physical properties or the anatomical structures of a neuron as you can see in this picture in general a neuron consists of the dendrites which are responsible for receiving information from other neurons the soma which integrates the information received by the dendrites and the axon which sends information to yet other neurons many past research has shown that nerve cells communicate with one another through electrical activity research on the electrical activity of the neuron was first conducted on the giant axon of a type of squid known as the lego squid this particular type of squid was chosen because of the large diameter of its neuronal axon which makes it possible to examine the neuron without using a microscope and therefore easier to measure its electrical activity measurement of the electrical activity of the squid axon is typically done using a specialized instrument known as the oscilloscope you can see a picture of the oscilloscope on the bottom part of this slide the oscilloscope is similar to a regular voltmeter but it is more precise than a voltmeter because it is able to detect changes in units of millivolts and milliseconds attached to the oscilloscope is a microelectrode which is inserted into the axon this microelectrode can either deliver an electrical current into the axon or it can also record electrical activity from the axon because axons use electrical conduction to transmit information the information transmission process can actually be completed relatively fast however considering that our body consists mostly of water the speed of information transmission can decrease as the information is transmitted down the length of the axon therefore to prevent the signal from getting weaker as it travels further the electrical impulse is repeatedly regenerated at multiple points down the length of an axon in this lecture you will learn about several important topics first you will be introduced to the concept of the resting potential in the neuron as well as the roles of the sodium potassium pump and the cell membrane's unique characteristics in producing this resting potential secondly we will look at the action potential and how the movements of the sodium and potassium ions contribute to the action potential we will also look at how the all or none law plays a role in the action potential of a neuron lastly we'll talk about the propagation of action potentials in particular in this last sub-topic we will learn about how action potentials in one part of the neuron is regenerated down the length of an axon up to the point that the action potential reaches the presynaptic terminals or terminal buttons of the neuron as a side note before we go any further i want to ask you to try to remember that in english the word sodium refers to the chemical molecule that we call natrium in indonesian similarly potassium in english refers to the molecule known as callium in indonesian