What are the primary cells contributing to the generation of EEG activity?

The generation of EEG activity is primarily linked to the behavior of pyramidal neurons. These neurons are the predominant excitatory cells in the cerebral cortex and are characterized by their unique pyramid-shaped cell body and long dendritic trees that extend to the cortical surface. The synaptic activity of these neurons is crucial in generating the electrical fields that can be detected on the scalp as EEG.

Pyramidal neurons are responsible for producing synchronized excitatory postsynaptic potentials (EPSPs) that contribute to the summation of electrical activity required for EEG signal generation. The organized and structured arrangement of these neurons in the cortical layers allows for effective synchronization of their activity, which is essential for the rhythmic patterns seen in EEG recordings.

While other cell types, such as interneurons and astrocytes, play supportive roles in the brain's functioning, they do not primarily contribute to the characteristic electrical signals observed in EEG. Interneurons, for example, are mainly involved in inhibitory signaling, and astrocytes support neuronal function but do not generate action potentials in the same way as pyramidal neurons do. Therefore, pyramidal neurons are central to the generation of EEG activity, making this answer the best choice.