discussion response to the following:

What are the different types of glial cells and their functions?

1. Microglia is the brain's immunity. It fights infections, diseases, injury (similar to white blood cells) and also detects when something is wrong and responds to attempt rendering the problem.
2. Astrocytes maintains a neuron's working environment by controlling neurotransmitter levels around synapses including controlling different ions (potassium, metabollic support, etc). Also, astrocytes have the ability to modulate how neurons communicate due to them being able to sense neurotransmitter levels and respond.
3. Oligodendrocytes supports axons of neurons in central nervous system that travels long distances. When this happens it produces myelin which is a fatty white substance in the brain and acts as insulation for axons and allows messages to pass faster.

How do glia compare to neurons in relative number?

1. The ratio of glia to neurons should be 1:1. According to the readings (that I had to read a few times to comprehend entirely) there has been extensive research throughout the years about the count. The ratio 10:1 became "common knowledge" under false pretenses and overlooking specific factors.

What role(s) do astrocytes play at the tripartite synapse?

1. Astrocytes play a support role for neuron's.Neurons are connected by synaptic connections which consist of presynaptic and postsynaptic neurons.
2. Monitor and alter synaptic function thus actively controlling synaptic transmission.

What type of signal do they use to communicate with neurons?

1. Glutamatergic synaptic activation of astrocytes. This stimulates the releases of ATP, glutamata, D-serine, etc through the activation of of pre/postsynaptic receptors which becomes the threshold for synaptic transmission.

In what ways does the thalamus function as a relay station in the brain? (Include sensory, motor, and cortico-cortical.)

1. The thalamus functions as a relay station in the brain because all information passes through the thalamus first before reaching it's final destination. Similar to a processing center or post office. The thalamus is divided into subcategories that deal with specific aspects. Sensory items would go through the sensory nuclei designated for sensory items.

What other roles does it play?

It regulates sleep, alertness, consciousness, awareness, attention, memory, cognition, etc.