The frontal lobe contains most of the dopamine-sensitive neurons in the cerebral cortex. The dopamine system is associated with reward, attention, short-term memory tasks, planning, and motivation. Dopamine tends to limit and select sensory information arriving from the thalamus to the forebrain.
Na + concentration is lowered, indicating that Na + in-flux is responsible for the rising phase of the action po-tential. Their data also suggested that the falling phaseof the action potential was caused by a later increase inK+ permeability.
Cation Versus Anion. Cations are ions with a net positive charge. Cation Examples: Silver: Ag +, hydronium: H 3 O +, and ammonium: NH 4 + Anions are ions with a net negative charge. Anion Examples: hydroxide anion: OH-, oxide anion: O 2-, and sulfate anion: SO 4 2-Because they have opposite electrical charges, cations and anions are attracted to each other.