Final answer:
In the case of meningitis, microglia are the first to have their functions disrupted as they act as the central nervous system's primary immune defense and respond quickly to infection.
Step-by-step explanation:
Meningitis is an inflammation of the meninges and can be caused by either bacterial or viral agents, but in the context of the question regarding which cell type is the first to have its function disrupted, the focus is on the impact of this condition on the central nervous system. The meninges are the protective layers covering the brain and spinal cord; hence, the inflammation associated with meningitis can severely affect neurological function. During meningitis, the cells likely to be first affected are the ones that are a part of the meninges, or that respond quickest to the infection.
The microglia, which are the resident immune cells in the central nervous system, often respond first to infection and injury and would likely be the first cell type to have its function disrupted in the case of meningitis. They are crucial in the brain's immune response, and are responsible for signaling other immune cells and clearing pathogens. Therefore, while neurons, astrocytes, and oligodendrocytes are all important glial cells within the CNS and can all be affected by meningitis, the microglia would be the first responders.