Complex sentence: Within the striatum, acetylcholine is the primary neurotransmitter, and the striatal dopamine-acetylcholine relationship is very important one: striatal output neurons receive inputs from the entire cerebral cortex and select relevant cortical information, and dopaminergic input from the pars compacta modulates the striatal output.
Split into simpler sentences: Within the striatum, acetylcholine is a key neurotransmitter, and the striatal dopamine-acetylcholine relationship is very important one. Striatal output neurons receive input from the entire cerebral cortex and select relevant cortical information, and dopaminergic input from the pars compacta modulates the striatal output.