Cerebral Hemispheres 2


Know Your Brain: Substantia Nigra

Where is the substantia nigra?

A cross-section of the brainstem showing the two substantia nigrae.

The substantia nigra is a region in the midbrain that is considered part of the basal ganglia. It looks like a darkened streak in unstained brain tissue; this is where it gets its name, which is Latin for "black substance." Although it is often referred to as one structure, there are actually two substantia nigrae, one on each side of the brainstem. Additionally, the substantia nigra itself is made up of two anatomically and functionally distinct portions: the substantia nigra pars compacta and the substantia nigra pars reticulata. Neurons in the pars compacta are much more densely packed together (or compact) than those in the pars reticulata.

What is the substantia nigra and what does it do?

Most of the dopamine neurons of the brain originate in the midbrain and are found in either the substantia nigra or the ventral tegmental area, which is located adjacent to the substantia nigra. The dopamine neurons in the substantia nigra express high levels of a pigment called neuromelanin, which accounts for their dark color. These dopamine neurons, however, are found predominantly in the substantia nigra pars compacta. The pars reticulata is instead populated largely by GABA neurons.

Watch this 2-Minute Neuroscience video to learn more about the substantia nigra.

Many of the dopamine neurons of the substantia nigra project to the striatum, another part of the basal ganglia that is made up of the caudate and putamen. In doing so they form a pathway called the nigrostriatal dopamine pathway that is thought to be crucial in the facilitation of movement.

The influence of the substantia nigra on movement is made apparent by observing the symptoms of Parkinson's disease, which are associated with the death of dopamine neurons in the substantia nigra pars compacta. Although it still isn't clear what exactly causes neurodegeneration in Parkinson's disease, when a significant number of these neurons have died, the individual will likely start to experience movement-related problems like tremors, rigidity, slowness of movement, and postural instability—all hallmark symptoms of Parkinson's disease.

Being one of the major dopamine-producing areas of the brain, however, the substantia nigra has functions that extend beyond just motor control. It is also thought to play important roles in a number of other functions and behaviors, including learning, drug addiction, and emotion.


Wichmann T, DeLong MR. 2013. The Basal Ganglia. In: Kandel ER, Schwartz JH, Jessell TM, eds. Principles of Neural Science, 5th ed. New York: McGraw-Hill.

Further reading:

Know your brain: Basal ganglia

Know your brain: Parkinson’s disease


Sleep. Memory. Pleasure. Fear. Language. We experience these things every day, but how do our brains create them? Your Brain, Explained is a personal tour around your gray matter. Building on neuroscientist Marc Dingman’s popular YouTube series, 2-Minute Neuroscience, this is a friendly, engaging introduction to the human brain and its quirks using real-life examples and Dingman’s own, hand-drawn illustrations.

  • ...a highly readable and accessible introduction to the operation of the brain and current issues in neuroscience... a wonderful introduction to the field. - Frank Amthor, PhD, Professor of Psychology, The University of Alabama at Birmingham, author, Neuroscience for Dummies

  • Reading like a collection of detective stories, Your Brain, Explained combines classic cases in the history of neurology with findings stemming from the latest techniques used to probe the brain’s secrets. - Stanley Finger, PhD, Professor Emeritus of Psychological & Brain Sciences, Washington University (St. Louis), author, Origins of Neuroscience

  • Dingman weaves classic studies with modern research into easily digestible sections, to provide an excellent primer on the rapidly advancing field of neuroscience. - Moheb Costandi, author, Neuroplasticity and 50 Human Brain Ideas You Really Need to Know

  • An informative, accessible and engaging book for anyone who has even the slightest interest in how the brain works, but doesn’t know where to begin. - Dean Burnett, PhD, author, Happy Brain and Idiot Brain


This book shows a whole other side of how brains work by examining the most unusual behavior to emerge from the human brain. In it, you'll meet a woman who is afraid to take a shower because she fears her body will slip down the drain, a man who is convinced he is a cat, a woman who compulsively snacks on cigarette ashes, and many other unusual cases. As uncommon as they are, each of these cases has something important to teach us about everyday brain function.

  • A unique combination of storytelling and scientific explanation that appeals to the brain novice, the trained neuroscientist, and everyone in between. Dingman explores some of the most fascinating and mysterious expressions of human behavior in a style that is case study, dramatic novel, and introductory textbook all rolled into one. - Alison Kreisler, PhD, Neuroscience Instructor, California State University, San Marcos

  • Bizarre is a collection of stories of how the brain can create zombies, cult members, extra limbs, instant musicians, and overnight accents, to name a few of the mind-scratching cases. After reading this book, you will walk away with a greater appreciation for this bizarre organ. If you are a fan of Oliver Sacks' books, you're certain to be a fan of Dingman's Bizarre. - Allison M. Wilck, PhD, Researcher and Assistant Professor of Psychology, Eastern Mennonite University

  • Dingman brings the history of neuroscience back to life and weaves in contemporary ideas seamlessly. Readers will come along for the ride of a really interesting read and accidentally learn some neuroscience along the way. - Erin Kirschmann, PhD, Associate Professor of Psychology & Counseling, Immaculata University

  • Through case studies of both exceptional people as well as those with disorders, Bizarre takes us on a fascinating journey in which we learn more about what is going on in our skull. - William J. Ray, PhD, Emeritus Professor of Psychology, The Pennsylvania State University, author, Abnormal Psychology