FIGURE 3.

Schematic diagram of the neural circuit for EEG theta oscillation. Light brown ellipsoids represent cholinergic neurons, blue ellipsoids represent glutaminergic neurons, dark brown ellipsoids represent GABAergic neurons, and green ellipsoid represents monoaminergic neurons. Blue connections and red connections represent excitatory and inhibitory connections, respectively. Blue and dark brown letters for neurons represent glutamatergic and GABAergic neurons, respectively. The neurons represented by only letters are not depicted in ellipsoid because the definition of their residing brain regions has not been established yet.