Biological Systems MCAT Practice Exam

What role do astrocytes play in the nervous system?

1. Guide neuron development

2. Generate action potentials

3. Form chemical synapses

4. Inhibit neurotransmitter uptake

The correct answer is: Guide neuron development

Astrocytes are a type of glial cell in the central nervous system and play several crucial roles that support and maintain neuronal function. Their ability to guide neuron development is particularly important during the formation of neural circuits. Astrocytes release various signaling molecules that influence the growth, differentiation, and migration of neurons and their processes. This guidance is essential for proper connectivity in the developing nervous system. Additionally, astrocytes contribute to maintaining the extracellular environment by regulating ion concentrations and recycling neurotransmitters released during synaptic transmission, although those are not their primary developmental roles. While astrocytes do not generate action potentials or form chemical synapses, they are involved in neurotransmitter uptake, helping to terminate neurotransmitter signaling and maintain synaptic health. Thus, the role of astrocytes in guiding neuron development stands out as foundational in establishing and sustaining the complex structure of neural networks.