Medicine and Health Sciences Commons^™

Differentiating Midbrain Structures In Parkinson’S Disease Using Magnetic Resonance Imaging, Erind Alushaj

Western Research Forum

Background: This study aims to differentiate two midbrain structures: substantia nigra pars compacta (SNc) and ventral tegmental area (VTA) in patients with early-stage Parkinson’s Disease (PD) using magnetic resonance imaging (MRI). The SNc degenerates earlier in PD causing motor symptoms; whereas, VTA degeneration occurs later leading to non-motor symptoms. Conventionally, the SNc and VTA project to the dorsal and ventral striatum respectively. Evidence suggests this model may be overly simplistic since the dorsal striatum has uneven dopamine loss in PD. So, the dorsal striatum was segmented into six functional subregions and only the caudal motor subregion showed early changes …

Clarifying Dopaminergic Projections Of The Ventral Tegmental Area And Substantia Nigra In Humans Using Structural Magnetic Resonance Imaging, Nicholas Handfield-Jones

Western Research Forum

Background

Dopaminergic (DA) pathways from the human midbrain to the striatum mediate movement, decision making, learning, and reward processing. Classically, the scientific consensus has been that there are two main DA pathways: the nigrostriatal and the mesolimbic pathways. In the nigrostriatal pathway, the substantia nigra par compacta (SNc) sends DA to the dorsal striatum (DS), and in the mesolimbic pathway, the ventral tegmental area (VTA) sends DA to the ventral striatum (VS) as well as prefrontal and limbic cortices. Recent findings, however, cast doubt on the accuracy of this model. It seems likely these DA projections are more overlapping and …