**3.1.1 Stratium**

Striatum has three anatomical divisions: caudate, putamen and ventral striatum or limbic29. It has bony neurons with the inhibitory neurotransmitter GABA and another subgroup which uses substance P and dynorphin. Striatum projects to globus pallidus and substantia nigra pars reticulata30. By the way, neurons with encephalin projects to external globus pallidus and subthalamic nucleus.

Boneless interneurons are divided into five subgroups: cholinergic and GABAergic neurons expressing parvualbumin; those expressing somatostatin; neuropeptide Y; nicotinamide adenine dinucleotide phosphatase and nitric oxide31.
