Glial Cells in AP Psychology

In AP Psychology, glial cells (neuroglia) are non-neuronal cells in the nervous system that support neurons by providing structure, insulation (myelin), communication, and waste transport. They don't fire action potentials themselves, but they keep neural transmission running smoothly.

What is Glial Cells?

Glial cells, also called neuroglia, are the support crew of the nervous system. The CED names two common types of cells in the brain. Neurons transmit information. Glial cells provide structure, insulation, communication, and waste transport (1.3.A.1). Together, these two cell types form the basis of the nervous system and are the building blocks of all behavior and mental processes.

Think of neurons as the performers and glia as the stage crew. The performers get the spotlight, but the show falls apart without the people building the set, running the wires, and cleaning up afterward. Different glial cells handle different jobs. Oligodendrocytes wrap axons in myelin, which insulates them and speeds up signals. Astrocytes give neurons physical structure and support. Microglia clear away waste and damaged material.

Why Glial Cells matters in AP® Psychology

Glial cells live in Unit 1: Biological Bases of Behavior, under Topic 1.3 The Neuron and Neural Firing. They are written directly into learning objective AP Psych 1.3.A, which asks you to explain how the structures and functions of typical neurons in the central nervous system affect behavior and mental processes. Essential knowledge 1.3.A.1 lists glial cells by name alongside neurons.

They also support AP Psych 1.3.B, which is about neural transmission. Glial insulation (myelin) is part of why transmission happens in an orderly, fast, systematic way. The CED points out that disruptions to that process can lead to disorders like multiple sclerosis. So glia help explain the healthy system and what happens when it breaks.

How Glial Cells connects across the course

Neurons and the Neuron vs. Glia Split (Unit 1)

The CED introduces glia as one half of a pair, with neurons as the other half. Neurons carry the message, and glia make sure the message can be carried. If a question describes a cell sending signals, that's a neuron. If it describes a cell supporting, insulating, or cleaning, that's a glial cell.

Myelin, Oligodendrocytes, and Neural Firing (Unit 1)

Oligodendrocytes are the glial cells that build the myelin sheath around axons in the brain and spinal cord. Myelin works like insulation on a wire, so the action potential travels faster and more efficiently. Damage the glia and the neurons still fire, just slower and less reliably. That's the logic behind practice questions where firing rates drop after glial damage.

Multiple Sclerosis as Disrupted Transmission (Unit 1)

Essential knowledge 1.3.B.1 names multiple sclerosis as a disorder caused by disruptions to neural transmission. In MS, the myelin that glial cells produce is damaged, so signals slow down or misfire. This is the clearest example of glial failure showing up as changes in behavior, like problems with movement and coordination.

Astrocytes and Microglia as Maintenance Crew (Unit 1)

The CED's list of glial jobs (structure, communication, waste transport) maps onto specific cells. Astrocytes hold neurons in place and support them. Microglia act as cleanup and defense, removing damaged cells and debris. If a question says a cell is 'removing damaged proteins,' think glia, and specifically microglia.

Is Glial Cells on the AP® Psychology exam?

Glial cells show up mostly in multiple-choice questions that test whether you can tell support cells from signaling cells. Common setups include:

• Identify the cell from its job. A stem describes brain cells removing damaged proteins or maintaining the structure of neural connections, and you pick glial cells (not neurons, not neurotransmitters).
• Interpret data. A question shows action potential frequencies dropping (say, from about 45-50 Hz to 15-20 Hz) after glial damage. You need to explain that glia don't generate the signal but support it, so losing them slows neural firing.
• Draw an inference. A brain region with an unusually high ratio of glial cells to neurons suggests that area has heavy support needs, such as lots of insulation, maintenance, or metabolic activity.

No released FRQ has used the term verbatim. Still, glia fit naturally into a free-response answer that asks you to explain how a neural structure affects behavior. A disorder like multiple sclerosis lets you link myelin damage to slower signals and then to physical symptoms. Your job is always to connect the cell's function to an effect on behavior or mental processes.

Glial Cells vs Neurons

Neurons are the cells that transmit information using action potentials and neurotransmitters. Glial cells do not send messages that way. They support neurons by providing structure, insulation, communication, and waste transport. A quick test is to ask whether the cell is sending the signal or helping the signal get sent. Sending means neuron. Helping means glia.

Key things to remember about Glial Cells

• Glial cells are non-neuronal cells that support neurons by providing structure, insulation, communication, and waste transport.

• The CED pairs glial cells with neurons as the two common cell types that form the basis of the nervous system and all behavior.

• Oligodendrocytes are glial cells that create the myelin sheath, which speeds up action potentials along the axon.

• When glial cells or myelin are damaged, as in multiple sclerosis, neural transmission slows down and behavior is affected.

• Microglia clean up waste and damaged material, while astrocytes provide physical structure and support for neurons.

• On the exam, identify glial cells by their supporting jobs, since neurons are the cells that actually transmit messages.

Frequently asked questions about Glial Cells

What are glial cells in AP Psychology?

Glial cells (neuroglia) are nervous system cells that support neurons by providing structure, insulation, communication, and waste transport. They appear in Topic 1.3 under learning objective AP Psych 1.3.A, where the CED lists them alongside neurons as the building blocks of behavior.

Do glial cells send messages like neurons do?

No. Glial cells don't transmit information through action potentials the way neurons do. They support neurons so those signals travel efficiently, which is why damaging glia can lower a neuron's firing rate without stopping it completely.

How are glial cells different from neurons?

Neurons transmit information, and glial cells support the neurons doing that work. Picture neurons as the wires carrying electricity and glia as the insulation, the brackets holding the wires up, and the cleanup crew.

Which glial cell makes myelin, and why does it matter?

Oligodendrocytes produce myelin in the central nervous system. Myelin insulates axons so action potentials move faster. When myelin is damaged, as in multiple sclerosis, signals slow down and movement and coordination can suffer.

Is multiple sclerosis the same as myasthenia gravis on the AP exam?

No. The CED names both as disruptions to neural transmission, but they break the system in different places. Multiple sclerosis involves damage to myelin, the insulation glial cells provide. Myasthenia gravis involves problems with acetylcholine signaling between nerves and muscles.