2. Astrocytes take up some neurotransmitters released from the axon terminals of neurons. For example, the neurotransmitter glutamate is taken into astrocytes and transformed into glutamine (fig. 7.10). The glutamine is then released back to the neurons, which can use it to reform the neurotransmitter glutamate.
3. The astrocyte end-feet surrounding blood capillaries take up glucose from the blood. The glucose is metabolized into lactic acid, or lactate (fig. 7.10). The lactate is then released and use as an energy source by neurons, which metabolize it aerobically into CO2 and H2O for the production of ATP.
4. Astrocytes appear to be needed for the formation of synapses in the CNS. Few synapses form in the absence of astrocytes, and those that do are defective. Normal synapses in the CNS are ensheathed by astrocytes (fig. 7.10).
5. Astrocytes induce the formation of the blood-brain barrier. The nature of the blood-brain barrier is described in the next section.
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This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.