Welcome to another blog post! This week has been fairly slow compared to other weeks, largely due to the lack of news from my lab. I’ll update you guys with that information at the end of the blog. In the meantime, although I’ve slowed down with the literature review, I have continued with online classes. In the past few lessons, I have learned a lot about the synapse and its role in transmitting information.
While many of you probably already know, the synapse is the junction between two neurons, specifically between the axon and dendrite of different neurons. However, there are two different types of synapses: electrical and chemical. Electrical synapses are essentially pores that allow ions to pass through, enabling the transmission of electrical signals. On the other hand, chemical synapses are more commonly found in the body, which uses neurotransmitters to invoke action potentials in the postsynaptic neuron. Here, the neurotransmitter crosses the synaptic cleft after an action potential is received by the presynaptic neuron, and binds to a specific receptor on the postsynaptic side.
Either way, the role of a synapse is to create a postsynaptic potential, which can be excitatory or inhibitory. Keep in mind that neurons receive many different signals, so the net postsynaptic response is the combination of many excitatory/inhibitory signals. To examine the details of how this works, let’s look at an example of a common Excitatory Postsynaptic Potentials (EPSPs), acetylcholine. When acetylcholine is released by an excitatory neuron, it traverses the synapse and binds to a Nicotinic-Acetylcholine Receptor (see image 1). When acetylcholine binds to both alpha subunits on the receptor, an EPSP is produced. Yet, an action potential is the sum of many EPSPs, which enable the postsynaptic neuron to reach its depolarization threshold.
Image 1: Nicotinic-Acetylcholine Receptor, top-down view.
While this is not directly related to my research, understanding postsynaptic potentials help paint a better picture of how neuronal population events, such as sharp-wave ripples, are produced. Other than my classes, I have been doing laboratory safety training in hopes of getting into the lab by next week. Although my senior project is coming to a close, I will continue with my independent research up until the senior project presentation date so I can present some of my findings to you guys. That’s all for this week. Catch you guys in the next one!