Medical/Neuroscience Making Everything Easier!™ The plain-English, easy-to-use N guide to neurobiology Open the book and find: o g y ol bi o • The essence of humans as e Neur Studying neurobiology and want an easy-to-use guide to intelligent life forms u the subject? This is the resource for you! The book covers • An overview of the human the basics—like the molecular mechanisms and anatomy of nervous system r the nervous system—and then moves on to more complex • The unique nervous system o subjects like neurodevelopmental biology. The book’s traits that make us human expert author delivers all this in an easy-to-read, fun guide b • Discussion of neurological to this complex subject! disorders such as Alzheimer’s i disease • Get started — dive into neurobiology with an introduction o to the subject, along with some of the big questions that • Easy-to-read explanations for neurobiologists have the answers to neurobiology students l o • Organize the nervous system — get an overview of the human • A complete overview of nervous nervous system and understand what it has in common with system anatomy the nervous system of other animals g • The lowdown on the mechanisms • The science of perception — find out how we perceive the world, of the nervous system y think, learn, and remember with an in-depth treatment of these topics • Disorders and treatments — discover the various neurological Cover image: ©iStockphoto.com/Vasiliy Yakobchuk disorders, the treatments for them, and the developments Learn to: that are coming in the future • Get a handle on neuroanatomy • All the extras — explore the unique human traits that arise from our complex, well-developed nervous system • Navigate neurological disorders and treatments Frank Amthor, PhD, is a professor of psychology at the University of Alabama and holds a secondary appointment in the UAB Medical Go to Dummies.com® • Score high in your neurobiology class School Department of Neurobiology. He has been an NIH-supported for videos, step-by-step examples, researcher for over 20 years and has published over 100 journal how-to articles, or to shop! • Understand neurological diseases articles and conference abstracts. $22.99 USA / $27.99 CAN / £15.99 UK ISBN:978-1-118-68931-8 52299 Frank Amthor, PhD 9 781118689318 Amthor Author of Neuroscience For Dummies® Get More and Do More at Dummies.com ® At home, at work, or on the go, Start with FREE Cheat Sheets Cheat Sheets include Dummies is here to help you • Checklists • Charts go digital! • Common Instructions • And Other Good Stuff! To access the Cheat Sheet created specifically for this book, go to www.dummies.com/cheatsheet/neurobiology Get Smart at Dummies.com Dummies.com makes your life easier with 1,000s of answers on everything from removing wallpaper to using the latest version of Windows. 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Any dissemination, distribution, or unauthorized use is strictly prohibited. Neurobiology For Dummies® Published by: John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030-5774, www.wiley.com Copyright © 2014 by John Wiley & Sons, Inc., Hoboken, New Jersey Published simultaneously in Canada No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning or otherwise, except as permitted under Sections 107 or 108 of the 1976 United States Copyright Act, without the prior written permission of the Publisher. Requests to the Publisher for permission should be addressed to the Permissions Department, John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030, (201) 748-6011, fax (201) 748-6008, or online at http://www.wiley.com/go/permissions. 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Contents at a Glance Introduction ................................................................ 1 Part I: Getting Started with Neurobiology ...................... 5 Chapter 1: Welcome to the World of Neurobiology ......................................................7 Chapter 2: Building Neurons from Molecules ..............................................................23 Chapter 3: Gating the Membrane: Ion Channels and Membrane Potentials .............47 Chapter 4: Sending Signals: Chemical Release and Electrical Activation .................67 Part II: Neuroanatomy: Organizing the Nervous System ......................................................... 83 Chapter 5: Movement Basics: Muscles and Motor Neurons ......................................85 Chapter 6: The Spinal Cord and the Autonomic Nervous System ...........................101 Chapter 7: The Busy Brain: Brainstem, Limbic System, Hypothalamus, and Reticular Formation .................................................................123 Chapter 8: Generating Behavior: Basal Ganglia, Thalamus, Motor Cor tex, and Frontal Cor tex .............................................................................145 Chapter 9: Topping It Off: The Neocortex ..................................................................159 Part III: Perceiving the World, Thinking, Learning, and Remembering ..................................... 183 Chapter 10: Looking at Vision and Hearing ................................................................185 Chapter 11: Feeling, Smelling, and Tasting .................................................................211 Chapter 12: Memory and Learning ..............................................................................233 Chapter 13: The Frontal Lobes and Executive Brain .................................................253 Chapter 14: Language, Intelligence, Emotions, and Consciousness ........................265 Part IV: Developmental, Neurological, and Mental Disorders and Treatments .............................. 283 Chapter 15: Developing the Brain and Nervous System ...........................................285 Chapter 16: Movement Disorders ................................................................................309 Chapter 17: Brain Dysfunction and Mental Illness ....................................................325 Chapter 18: Making Better Brains ................................................................................341 These materials are © 2014 John Wiley & Sons, Inc. Any dissemination, distribution, or unauthorized use is strictly prohibited. Part V: The Part of Tens ........................................... 355 Chapter 19: The Ten Most Important Brain Circuits .................................................357 Chapter 20: Ten Technologies Revolutionizing Brain Science ................................365 Index ...................................................................... 373 These materials are © 2014 John Wiley & Sons, Inc. Any dissemination, distribution, or unauthorized use is strictly prohibited. Table of Contents Introduction ................................................................. 1 About This Book ..............................................................................................2 Foolish Assumptions .......................................................................................2 Icons Used in This Book .................................................................................3 Beyond the Book .............................................................................................3 Where to Go from Here ...................................................................................4 Part I: Getting Started with Neurobiology ...................... 5 Chapter 1: Welcome to the World of Neurobiology . . . . . . . . . . . . . . . . 7 Introducing Neurons .......................................................................................8 Evolving cells on early earth ................................................................8 Multicellularity: Sensing and moving ..................................................9 Cellular motors.....................................................................................10 Coordinating responses in simple circuits .......................................11 Organizing the Nervous System ..................................................................12 Movement basics: Muscles and motor systems ..............................13 The spinal cord and autonomic nervous system ............................13 The brainstem, limbic system, hypothalamus, and reticular formation ...................................................................14 Basal ganglia, cerebellum, motor and premotor cortex, and thalamus ....................................................................................15 The neocortex ......................................................................................16 Perceiving the World, Thinking, Learning, and Remembering ................17 Looking at vision and audition ...........................................................17 Feeling, smelling, and tasting .............................................................18 Learning and memory: Circuits and plasticity .................................18 The frontal lobes and executive brain ..............................................19 Language, emotions, lateralization, and thought ............................19 Developmental, Neurological, and Mental Disorders and Treatments..................................................................................................20 Developing the brain and nervous system .......................................21 Movement disorders and symptoms ................................................21 Neural dysfunctions and mental illness ............................................22 Repair and enhancement with artificial brains ................................22 These materials are © 2014 John Wiley & Sons, Inc. Any dissemination, distribution, or unauthorized use is strictly prohibited. vi Neurobiology For Dummies Chapter 2: Building Neurons from Molecules . . . . . . . . . . . . . . . . . . . . 23 Getting into Genetics .....................................................................................23 Introducing inheritance ......................................................................24 Greeting chromosomes and genes ....................................................25 Replicating DNA and the cell life cycle .............................................26 Coding for proteins: RNA and DNA ....................................................27 Regulating genes ..................................................................................29 Meeting Cell Molecules: Important Ions and Proteins ..............................31 Eyeing important ions .........................................................................32 Sizing up proteins ................................................................................33 Going through membrane proteins ...................................................33 Peeking at the Parts of a Cell ........................................................................33 Cytoplasm and organelles ..................................................................34 Nucleus ..................................................................................................34 Secretion and hormones .....................................................................35 Setting Boundaries: Cell Membrane Lipids ................................................36 Focusing on phospholipid chemistry ................................................37 Seeing cells’ differences ......................................................................39 Regulating Water and Cell Volume ..............................................................40 Observing osmotic pressure ..............................................................40 Responding to osmotic challenges ....................................................40 Moving water with aquaporins ..........................................................41 Knowing the Neuron: Not Just Another Cell .....................................................41 Noticing neuron anatomy ...................................................................41 Understanding what neurons do .......................................................43 When Things Go Wrong: Genetics and Neurological Illness ....................44 Mutations and transcriptional errors ...............................................44 Modifying genes: Fixing or Frankenstein? .........................................46 Chapter 3: Gating the Membrane: Ion Channels and Membrane Potentials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Looking at Membrane Channels ..................................................................47 Talking about transporters .................................................................48 Checking out channels ........................................................................48 Getting a Charge Out of Neurons .................................................................50 Pumping Ions for Information ......................................................................50 Sodium-potassium pump ....................................................................50 Other important pumps ......................................................................52 Discovering Diffusion and Voltage ..............................................................52 The Nernst equation ............................................................................53 The Goldman–Hodgkin–Katz equation..............................................54 Signaling with Electricity in Neurons ..........................................................56 Exploring potential ..............................................................................56 Controlling ion permeability: Gated channels .................................56 These materials are © 2014 John Wiley & Sons, Inc. Any dissemination, distribution, or unauthorized use is strictly prohibited. vii Table of Contents Making Spikes with Sodium and Potassium Channels ..............................57 Getting back to resting potential .......................................................57 Voltage-dependent channels ..............................................................58 Reaching action potential ...................................................................58 Cable properties of neurons: One reason for action potentials ...............................................................................61 Insulating with Glial Cells .............................................................................65 Chapter 4: Sending Signals: Chemical Release and Electrical Activation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .67 Looking at Synaptic Transmission ..............................................................67 Checking out chemical synapses and neurotransmitter release ................................................................68 Eyeing electrical synapses at gap junctions .....................................72 Being Receptive to Neurotransmitter Receptors ......................................74 Introducing ionotropic receptors ......................................................75 Meeting metabotropic receptors and second messenger systems ..........................................................................76 Making connections with the neuromuscular junction ..................78 Dividing and Conquering: Interneurons and Circuits ...............................79 Pooling sensory input .........................................................................80 Coordinating motor output ................................................................81 Comparing brains to computers ........................................................81 Part II: Neuroanatomy: Organizing the Nervous System .......................................................... 83 Chapter 5: Movement Basics: Muscles and Motor Neurons . . . . . . . 85 Making a Move: Muscle Types and What They Do ....................................86 Processing with smooth muscle ........................................................86 Striated muscle for hearts and limbs ................................................86 Twitching fast and slow: Muscle composition .................................88 Pulling Your Weight: How Muscle Cells Contract .....................................88 Releasing acetylcholine.......................................................................89 Patterning muscle contractions .........................................................89 Alpha motor neurons ..........................................................................90 The motor unit .....................................................................................90 Sliding filaments: Actin and myosin ..................................................91 Controlling Muscle Contraction ..................................................................92 Modulating firing rate ..........................................................................93 Recruiting motor neurons ..................................................................94 Knowing Where Your Limb Is Located .......................................................94 Muscle spindle and gamma motor neurons .....................................95 Golgi tendon organs ............................................................................95 Joint receptors for position ................................................................95 These materials are © 2014 John Wiley & Sons, Inc. Any dissemination, distribution, or unauthorized use is strictly prohibited. viii Neurobiology For Dummies Reflexing without Reflecting ........................................................................96 Withdrawing a limb .............................................................................96 Staying put ............................................................................................96 Seeing the spinal flexor reflex ............................................................97 Keeping the spinal cord in the loop ..................................................97 Monosynaptic and polysynaptic reflexes .........................................97 Overriding a reflex ...............................................................................98 Exercise and Aging ........................................................................................99 Use it or lose it: The effects of exercise ............................................99 Slowing down with age ........................................................................99 Muscle mass in men and women .....................................................100 Chapter 6: The Spinal Cord and the Autonomic Nervous System . . . .101 Segmenting the Spine ..................................................................................102 Cervical nerves ...................................................................................103 Thoracic nerves .................................................................................105 Lumbar nerves ...................................................................................105 Sacral nerves ......................................................................................105 Spinal membranes .............................................................................106 Spying on the Spinal Cord ..........................................................................106 Dorsal inputs, ventral outputs .........................................................107 Reflecting on what hit you: The basic spinal reflex.......................109 Spinal pattern generators .................................................................110 Feeling and Acting: The Peripheral Nervous System ..............................112 Getting stimulated by neural sensors .............................................112 Moving around: Neural effectors .....................................................113 Correcting Errors: The Cerebellum ...........................................................114 Cerebellar structure ..........................................................................115 Stepping in holes and what to do about it ......................................116 Carrying the load: Feed-forward force calibration ........................117 Cerebellar circuits .............................................................................118 Fighting or Fleeing: The Autonomic Nervous System .............................119 The two main subdivisions of the autonomic nervous system ...119 The autonomic nervous system input and output ........................121 Chapter 7: The Busy Brain: Brainstem, Limbic System, Hypothalamus, and Reticular Formation . . . . . . . . . . . . . . . . . . . . . . . . 123 The Brainstem: Medulla, Pons, Midbrain .................................................124 Meeting the medulla ..........................................................................125 Presenting the pons ...........................................................................127 Mentioning the midbrain ..................................................................128 Counting the Cranial Nerves ......................................................................129 Controlling Your Motives: The Limbic System ........................................131 Mesocortex and allocortex versus neocortex ................................133 Organizing thoughts and activities: The cingulate gyrus .............133 Making memories: The hippocampus .............................................134 The amygdala .....................................................................................136 These materials are © 2014 John Wiley & Sons, Inc. Any dissemination, distribution, or unauthorized use is strictly prohibited.