Cerebral Hemispheres 2
NEUROSCIENTIFICALLY CHALLENGED

NEUROSCIENCE MADE SIMPLER

Drugs, Love, & War: All the Same to the Brain?


In many ways, of course, the brain handles drugs, love, and violence drastically differently. Researchers have been aware for some time, however, that love and drugs also have many similarities in how they are processed by the brain. A neurotransmitter called dopamine has been found to be necessary for participation in drug-seeking or love-seeking behavior. In fact, it has been implicated in nearly every experience we consider rewarding, such as love, drugs, eating, and sex. This has caused one of the primary dopaminergic systems of the brain, the mesolimbic dopamine pathway (along with other accompanying structures) to be referred to as the reward system of the brain. Originally it was thought that this system must be responsible for the euphoric effects one feels when using drugs or while experiencing romantic love. Later experiments showed, however, that it is more likely dopamine is necessary for reinforcement--for helping the brain to remember what experiences were rewarding, and what clues in the environment to look for in order to facilitate the reoccurrence of those experiences. For example, an ex-smoker might get a whiff of cigarette smoke from a passerby and feel a craving to have a cigarette. This associative memory experience is probably due to dopamine.

Now for the first time researchers have drawn a direct connection between dopamine and aggression. Many of us have felt the surge of energy that accompanies watching a boxing match, or a fight during a hockey game, and some may even have been embarrassed when overcome with such a "primal" emotion. Maria Couppis and other researchers at Vanderbilt University conducted an experiment with mice to further explore this violence-associated euphoria. In the experiment a male and female mouse were kept together in a cage and several other mice were kept in a separate cage. The female mouse was removed and replaced with one of the intruder mice, provoking an aggressive response by the "home" male mouse. The female mouse was returned and the intruder removed. The home mouse was then trained to push a target with its nose in order to have the intruder mouse put back into the cage, when it would again behave aggressively toward it. The fact that the mouse continually pushed the target indicates the opportunity to engage in the aggressive defense may have been rewarding to the mouse. Then the mouse was treated with a dopamine antagonist, which blocks the activity of dopamine. This significantly reduced the mouse's target-pushing behavior. The experiment was repeated with a number of different mice, and with changes in environment, with similar results.

This experiment is the first to demonstrate a distinct similarity between violence and other reward seeking behavior. Why would our brains put violence in the same category as sex? The consensus opinion on rewarding behavior of any kind is there must have been an evolutionary advantage in pursuing that type of behavior in order for it to become part of our reward system. The evolutionary advantage of eating, for example, is obvious (it's necessary for survival), so it makes sense we should have evolved so eating is enjoyable for us. The same is true for sex. Without it we can't achieve our evolutionary goal of procreation, so it should be something we want to pursue. Aggression had its own evolutionary advantage. It was necessary to our ancestors in order to protect offspring, mates, territory, and food. So perhaps the fascination many of us have with violence comes from a brain system that evolved in a time when aggression was a necessary part of survival. It is important to mention, however, that just because violence may be a natural part of our evolutionary past does not mean it still holds a place in today's environment or behavior.

YOUR BRAIN, EXPLAINED

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.

  • 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

  • ...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

BIZARRE

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.

  • 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

  • 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

  • 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