Organisation of the dopamine neuronal subsets within midbrain of the Pygmy Acrobat.

Pygmy Acrobat has unique set of morphological, anatomical and behavioral features that make it a promising model for study of primate evolution. Among the many locomotor adaptations, it should be mark a wide range of movements such as gliding, climbing, running, arboreality. This type of behavior can result from differences in anatomy and physiology of the brain systems involved in its integration. It is well acknowledged that dopaminergic neurons are involved in motor control, motivation and cognition. Due to the fact that there are no data on morphological organisation of dopaminergic system in the midbrain of Acrobates pygmaeus, we decide to do this using immunohistochemical and quantitative methods. Our study showed that the general distribution and characteristics of the dopaminergic cells within midbrain nuclei of the pygmy acrobat is similar to other species but some variabilities lacking the substantia nigra compact part ventral tier and "tail" of the substantia nigra compact part were observed. We hope that this study significantly broadens our knowledge and provides new details about organization of the dopaminergic cells in the midbrain nuclei of the Pygmy Acrobat.