Glial Cells and Astrocyte Assisted Activities

00:01 Glial Cells.

00:03 Glial cells are accessories cells in the nervous system.

00:07 So these are not neurons per se but think of them more as helper cells.

00:13 There are gonna be different types of helper cells in different areas of the body.

00:18 So if we look at the peripheral nervous system, we have something like Schwann cells.

00:23 Schwann cells wrap around axons and form these myelination.

00:30 Satellite cells also available in the peripheral nervous system.

00:35 These are primarily in ganglia.

00:37 And they help to regulate the chemical environment of the ganglia.

00:42 If we look at the enteric nervous system, Remember, this is the nervous system around the GI tract and the gut.

00:49 You also have enteric nervous cell, gluteal cells.

00:53 These act very much like the satellite cells and there in ganglia primarily and they have a number of functions including regulating the chemical environment.

01:05 The central nervous system is more complex.

01:09 It’s the brain. It’s the spinal cord.

01:11 You know that this is going to be even more tightly regulated.

01:16 Having more tightly regulated something, you need to have more different service neurons around.

01:25 So the first few of these service neurons have to do with very specific functions in places like the retina, in white matter, in gray matter, and they involve a lot of things like nutrient delivery and repair processes.

01:41 You also have other ones that help build new neurons. This is involves synaptic plasticity to be able to link up various nervous projections.

01:54 Once you reach things like oligodendrocytes, these act a lot like the Schwann cells did in the peripheral nervous system.

02:02 It involves myelination around various axons.

02:07 You have microglia that help respond to trauma events, such as if the cerebral nervous system was damage.

02:15 And finally, you have various specialized cells that will allow for the formation of cerebral spinal fluid.

02:23 These ependymal cells are located along some portions of the ventricles.

02:28 And what actually make cerebral spinal fluid and brain extracellular fluid that bades all the different cells in the brain.

02:39 So let’s talk through ependymal cells and how these process of cerebral spinal fluid formation occurs.

02:47 Astrocytes, and how they help regulate in terminal environments? Astrocytes are going to be important processes to sometimes recycle neurotransmitters.

03:03 And what I mean by that, is you have a normal axon that releases a quanta of neurotransmitter.

03:11 And what do you do with that neurotransmitter once it’s been released? It often times is broken down into something else.

03:19 But, is that axon terminal going to be able to reabsorb it? Or does something else surround it help clean it up and then move it back to the spot that it needs to be, to be released again? In this case, astrocytes can serve this function of helping to clean up a neurotransmitter, change in it back into its active form, and then delivering it back to the nerve to be released again.

03:49 This example that we have here is about glutamate.

03:53 Glutamate is released from post-synaptic nerve terminals.

03:58 It is taken up by astrocytes.

04:03 You convert to glutamate back into glutamine.

04:07 and then you transport glutamine to that axon terminal.

04:13 This process allows for the recycling of this neurotransmitter.

04:19 So astrocytes do have this capability of helping to not only deliver nutrients, to do things like repair processes but even participate in helping to recycle neurotransmitters.