Neuroscience For Dummies

Title Page
Copyright Page
Table of Contents
Introduction
About This Book
Foolish Assumptions
Icons Used in This Book
Beyond This Book
Where to Go from Here
Part 1 Introducing the Nervous System
Chapter 1 A Quick Trip through the Nervous System
Understanding the Evolution of the Nervous System
Specializing and communicating
Moving hither, thither, and yon — in a coordinated way
Evolving into complex animals
Enter the neocortex
Looking at How the Nervous System Works
The important role of neurons
Computing in circuits, segments, and modules
What a charge: The role of electricity
Understanding the nervous system’s modular organization
Looking at the Basic Functions of the Nervous System
Sensing the world around you
Moving with motor neurons
Deciding and doing
Processing thoughts: Using intelligence and memory
Language
Episodic memory
When Things Go Wrong: Neurological and Mental Illness
Revolutionizing the Future: Advancements in Various Fields
Treating dysfunction
Pharmacological therapies
Transplants
Electrical stimulation
Neural prostheses
Genetic therapies
Augmenting function: Changing who we are
Chapter 2 All about the Brain and Spinal Cord
Looking Inside the Skull: The Brain and Its Parts
The neocortex: Controlling the controllers
Finding your way around the neocortex: Dorsal, ventral, anterior, and posterior
Grooves and ridges: The sulci and gyri
The left and right hemispheres
The four major lobes
The parietal lobe
The occipital lobe
The temporal lobe
Below the neocortex: The thalamus
The limbic system and other important subcortical areas
The hippocampus
The amygdala
Orbitofrontal cortex
The anterior cingulate cortex
The basal ganglia
Transitioning between the brain and the spinal cord
The midbrain
The reticular formation
Processing the basics below the midbrain: The pons and medulla
Coordinating movement: The cerebellum
Looking at differences: Size, structure, and other variations
Mine’s bigger than yours!
It’s what’s inside that counts: Looking at differences in structural organization
Considering gender-based brain differences
The Spinal Cord: The Intermediary between Nervous Systems
Looking at the spinal reflex
Getting your muscles moving
Fighting or Fleeing: The Autonomic Nervous System
How We Know What We Know about Neural Activity
Examining problems caused by brain injuries
Using technology to image the brain: From early EEGs to today
PET and SPECT
fMRI
MEG
DTI
Optical imaging
Chapter 3 Understanding How Neurons Work
Neuron Basics: Not Just Another Cell in the Body
Sending and receiving info between neurons: Synaptic receptors
Looking at the receptors: Pre- and postsynaptic components
Firing off spikes to other neurons
Receiving input from the environment: Specialized receptors
Ionotropic versus metabotropic receptors
The three major functional classes of neurotransmitters
How Shocking! Neurons as Electrical Signaling Devices
Yikes, spikes: The action potential
The problems with getting from here to there
Helping the signal along: Voltage-dependent sodium channels
Jumping from node to node
Closing the loop: From action potential to neurotransmitter release
Moving Around with Motor Neurons
Non-neuronal Cells: Glial Cells
Astrocytes
Oligodendrocytes and Schwann cells
Microglial cells
Recording Techniques
Single extracellular microelectrodes
Microelectrode arrays
Sharp intracellular electrodes
Patch-clamp electrodes
Optical imaging devices
Part 2 Translating the Internal and External Worlds through Your Senses
Chapter 4 Feeling Your Way: The Skin Senses
How Do You Feel? The Lowdown on the Skin and Its Sensory Neurons
General properties of the skin
Sensing touch: The mechanoreceptors
Merkel disks
Meissner’s corpuscles
Ruffini corpuscles
Pacinian corpuscles
How mechanoreceptors work
Sensing temperature and pain
Sensing position and movement: Proprioception and kinesthesis
Skin Receptors, Local Spinal Circuits, and Projections to the Brain
Somatosensory receptor outputs
Locating the sensation: Specialized cortical sensory areas
Mapping skin receptors to specific brain areas: Cortical maps
Receptor densities
Understanding the Complex Aspects of Pain
Reducing — or overlooking — pain
Neurotransmitters that reduce or block pain
Using distraction to alleviate pain: The gate theory
Pain-free and hating it: Peripheral neuropathy
Chronic pain and individual differences in pain perception
Chapter 5 Looking at Vision
The Eyes Have It: A Quick Glance at Your Eyes
The retina: Converting photons to electrical signals
Catching photons: Light and phototransduction
Getting the message to the brain
More photoreceptors in the center of the eye
Modulating responses around average light level
Minimizing information across space
Processing signals from the photoreceptors: Horizontal and bipolar cells
Step 1: Reducing redundant signals (horizontal cells and lateral inhibition)
Step 2: On to bipolar cells and to the processing layers beyond
Sending out and shaping the message: Ganglion and amacrine cells
Converting analog to digital signals to go the distance
Breaking down into ganglion cell types and classes
From the Eyes to the Vision Centers of the Brain
Destination: Thalamus
Crossing to the other side: The left-right sorting of images
Looking at the visual signal in the thalamus
Other destinations
The superior colliculus: Controlling eye movement
The accessory optic and pretectal nuclei
The suprachiasmatic nucleus
The Edinger-Westphal nucleus
From the thalamus to the occipital lobe
What happens in V1 and other visual areas
Looking at the dorsal and ventral streams
The dorsal stream
The ventral stream
Crosstalk between the dorsal and ventral streams
Impaired Vision and Visual Illusions
Looks the same to me: Color blindness
Understanding blindness
Visual illusions
Chapter 6 Sounding Off: The Auditory System
The Ear: Capturing and Decoding Sound Waves
Gathering sound: The outer ear
The pinna, the first part of the outer ear
Sailing into the auditory canal
Banging the (ear)drum
The middle ear
Playing chords to the brain: The inner ear
Opening ion channels to fire action potentials
Sending information about frequency and amplitude
Making Sense of Sounds: Central Auditory Projections
Stops before the thalamus
Off to the thalamus: The medial geniculate nucleus
Processing sound in the brain: The superior temporal lobe
Handling complex auditory patterns
Hearing with meaning: Specializations for language
Perceiving music: I’ve got rhythm
Locating Sound
Computing azimuth (horizontal angle)
Interaural intensity difference
Interaural time difference
Detecting elevation
I Can’t Hear You: Deafness and Tinnitus
Hearing loss
Oh those bells bells bells bells bells bells bells: Tinnitus
Chapter 7 Odors and Taste
What’s That Smell?
Sorting things out through the olfactory bulb
Projecting along different paths
Looping between the orbitofrontal cortex and the mediodorsal thalamus
Projecting to the pyriform cortex and the amygdala
Projecting to the entorhinal cortex and hippocampus
Projecting straight to the amygdala
Getting more specific in the orbitofrontal cortex
Having Good Taste
The discriminating tongue: The four basic tastes
Sweet
Salt
Sour
Bitter
Sending the taste message to the brain: Taste coding
Projecting to the brain stem via the chorda tympani and the glossopharyngeal nerve
Distributed versus labeled line coding
Identifying and remembering tastes
The Role of Learning and Memory in Taste and Smell
Lacking Taste and Smelling Badly
Smelling poorly or not at all
Satiety
Part 3 Moving Right Along: Motor Systems
Chapter 8 Movement Basics
Identifying Types of Movement
Movements that regulate internal body functions
Reflexive movements
Planned and coordinated movements
Controlling Movement: Central Planning and Hierarchical Execution
Activating non-voluntary muscle movements
Activating the withdrawal reflex
Stepping up the hierarchy: Locomotion
Using your brain for complex motor behavior
Pulling the Load: Muscle Cells and Their Action Potentials
Muscle and Muscle Motor Neuron Disorders
Myasthenia gravis
Amyotrophic lateral sclerosis
Motor neuron viral diseases: Rabies and polio
Spinal cord injury
Chapter 9 Coordinating Things More: The Spinal Cord and Pathways
The Withdrawal Reflex: An Open-Loop Response
Hold Your Position! Closed-Loop Reflexes
Opposing forces: Extensor-flexor muscle pairs
Determining the correct firing rate with the comparator neural circuit
The Modulating Reflexes: Balance and Locomotion
Maintaining balance: The vestibulospinal reflex
Do the locomotion
The basics of locomotion
Alternating limb gaits: Spinal pattern generators
Correcting Errors without Feedback: The Cerebellum
Looking at cerebellar systems
Predicting limb location during movement
Focusing on cortical and brain-stem control of movement
Chapter 10 Planning and Executing Actions
Making the Move from Reflexes to Conscious or Goal-Generated Action
How the frontal lobes function
Sending messages from the primary motor cortex to the muscles
Setting the goals of motor activity
Planning, correcting, learning: Prefrontal cortex and subcortical processors
Working memory
Initiating actions: Basal ganglia
In the middle of things: Supplementary and pre-motor areas
The premotor cortex: Learning how to get it right
The supplementary motor cortex: Breezing right through
The cerebellum: Where you coordinate and learn movements
Putting it all together
Where Are the Free Will Neurons?
Which comes first: The thought or the action?
Contemplating the study results
You’re still accountable!
Discovering New (and Strange) Neurons
Mirror neurons
Von Economo neurons
Where these neurons are found
Speculation about what these neurons do
When the Wheels Come Off: Motor Disorders
Myasthenia gravis
Injuries to the spinal cord and brain
Degeneration of the basal ganglia
Parkinson’s disease
Huntington’s disease
Chapter 11 Unconscious Actions with Big Implications
Working behind the Scenes: The Autonomic Nervous System
Understanding the functions of the autonomic nervous system
Matching the activity levels of different organs
Letting us switch between quiet and active states
Dividing and conquering: Sympathetic and parasympathetic subsystems
The sympathetic subsystem: Fight or flight
The parasympathetic subsystem: All is well!
Controlling the autonomic nervous system
Getting sensory feedback from target organs
The hypothalamus: Controlling the sympathetic and parasympathetic subsystems
Crossing signals: When the autonomic nervous system goes awry
Sweet Dreams: Sleep and Circadian Rhythms
Synchronizing the biological clock with light exposure
Intrinsic versus real world cycle times
The role of retinal ganglion cells
Looking at the different stages of sleep
NREM sleep
REM sleep
Functional associations of brain rhythms
Alpha rhythms
Beta waves
Gamma waves
Delta waves
Theta
Controlling the sleep cycles
Not so sweet dreams: Fighting sleep disorders
Part 4 Intelligence: The Thinking Brain and Consciousness
Chapter 12 Understanding Intelligence, Consciousness, and Emotions
Defining Intelligence
Understanding the nature of intelligence: General or specialized?
Sensory pathways to specific areas of the brain
Localization, plasticity, and recovery from brain damage
Components of intelligence
Biological variations
Upbringing
Intelligence as an adaptive behavior
Looking at the different levels of intelligence
Intelligence about Emotions
Tapping into memories of strong emotional reactions
Emoting about the limbic system
The hippocampus
The amygdala
The anterior cingulate cortex
The orbitofrontal cortex
Understanding Consciousness
Looking at assumptions about consciousness
Types of consciousness
Studying consciousness
Sleep versus waking
Coma versus paralysis
Brain damage
Two camps and a middle ground
Unconscious processing: Blindsight, neglect, and other phenomena
The “cocktail party” situation
Blindsided by blindsight
Subliminal perception and priming
Being neglected
Chapter 13 How the Brain Processes Thoughts
The Brain: Taking Command at Multiple Levels
All about the Neocortex
The four major lobes of the brain and their functions
Gray matter versus white matter
Universal versus small-world connectivity
Minicolumns and the six degrees of separation
Defining the six-layered structure of the cortex
The job of the pyramidal cells
The canonical circuit
Hail to the neocortex!
Controlling the Content of Thought: Sensory Pathways and Hierarchies
Sensory relays from the thalamus to the cortex
Projecting from the thalamus to each sense’s primary cortex
Projecting back to the thalamus and other regions in the cortex
Thalamic integration and gating functions
The hippocampus: Specializing for memory
Dividing and Conquering: Language, Vision, and the Brain Hemispheres
Specialized brain systems for language
Wernicke’s area
Broca’s area
Seeing the whole and the parts: Visual processing asymmetries
Where Consciousness Resides
Language and left- or right-hemisphere damage
Understanding the “left side interpreter”
Chapter 14 The Executive Brain
Getting the Brain You Have Today: The Neocortex versus Your Reptilian Brain
My neocortex is bigger than yours: Looking at relative sizes
The relationship between prefrontal cortex size and the ability to pursue goals
Working Memory, Problem-Solving, and the Lateral Prefrontal Cortex
Brain processes managing working memory
The limits of working memory
Perseveration: Sticking with the old, even when it doesn’t work anymore
Making Up and Changing Your Mind: The Orbitofrontal Cortex
Feeling it in your gut: Learned emotional reactions
Gambling on getting it right: Risk taking, aversion, and pleasure
Case-based reasoning: Thinking about social consequences
Are We There Yet? The Anterior Cingulate Cortex
Logging errors and changing tactics
Acting without thinking
Who’s minding the store? Problems in the anterior cingulate cortex
Chapter 15 Learning and Memory
Learning and Memory: One More Way to Adapt to the Environment
Developmental adaptations
Classical learning
Sending More or Fewer Signals: Adaptation versus Facilitation
Adaptation
Facilitation
Studying habituation and sensitization in sea slugs
Exploring What Happens during Learning: Changing Synapses
Neural computation: Neural AND and OR gates
The McCulloch-Pitts neuron
Rewiring your brain: The NMDA receptor
Introducing the NMDA receptor
The NMDA receptor in action
Strengthening the synapse: Long-term potentiation
The Role of the Hippocampus in Learning and Memory
Going from short- to long-term memory
A matrix of coincidence detectors
Remembering as knowing: Cortical mechanisms
Knowing versus knowing that you know: Context and episodic memory
Losing Your Memory: Forgetting, Amnesia, and Other Disorders
Getting Brainier: Improving Your Learning
Distributing study time over many shorter sessions
Getting enough sleep
Practicing in your mind
Rewarding and punishing
Chapter 16 Developing and Modifying Brain Circuits: Plasticity
Developing from Conception
Arising from the ectoderm: The embryonic nervous system
The hindbrain, midbrain, and forebrain: The divisions of the ectoderm
Ontogeny does not recapitulate phylogeny, but it looks that way
Adding layers: The development of the cerebral cortex
Neural stem cells and migratory precursor cells
Gluing things together: Glial cells and development
Migrating along radial glial cells and differentiating
Wiring it all together: How axons connect various areas of the brain to each other
Chemical affinities and cell surface markers
Putting together the basic brain structure
Learning from Experience: Plasticity and the Development of Cortical Maps
Mapping it out: Placing yourself in a visual, auditory, and touching world
Firing and wiring together: Looking at Hebb’s law
Understanding Hebb’s law
Applying Hebb’s law to cortical maps
Environmental effects: Nature versus nurture
Genetics: Specifying the brain-building procedure
Taking the Wrong Path: Nervous System Disorders of Development
Looking for genetic developmental errors in mutant mice
Environmental effects on development of the human brain
The Aging Brain
Living long and well: Lifespan changes in brain strategy
Accumulating insults: Aging-specific brain dysfunctions
Alzheimer’s disease
Parkinson’s disease
Autoimmune diseases
Strokes
Tumors
Chapter 17 Neural Dysfunctions, Mental Illness, and Drugs That Affect the Brain
Looking at the Causes and Types of Mental Illness
Genetic malfunctions
Developmental and environmental mental illness
Mental illness with mixed genetic and developmental components
Feeling blue: Depression
Experiencing seizures in the brain: Epilepsy
Disordered and psychotic thoughts: Schizophrenia
Obsessing about OCD
The Promise of Pharmaceuticals
Typical and atypical antipsychotic medications
Drugs affecting GABA receptors
Drugs affecting serotonin
Drugs affecting dopamine
Some natural psychoactive substances
Part 5 The Part of Tens
Chapter 18 Ten (or So) Crucial Brain Structures
The Neocortex
The Thalamus, Gateway to the Neocortex
The Pulvinar
The Cerebellum
The Hippocampus
Wernicke’s and Broca’s Areas
The Fusiform Face Area
The Amygdala
The Lateral Prefrontal Cortex
The Substantia Nigra (Basal Ganglia)
The Anterior Cingulate Cortex
Chapter 19 Ten Tricks of Neurons That Make Them Do What They Do
Overcoming Neurons’ Size Limit
Getting the Biggest Bang for the Buck with Dendritic Spines
Ligand-Gated Receptors: Enabling Neurons to Communicate Chemically
Getting Specialized for the Senses
Computing with Ion Channel Currents
Keeping the Signal Strong across Long Distances
The Axon: Sending Signals from Head to Toe
Speeding Things Up with Myelination
Neural Homeostasis
Changing Synaptic Weights to Adapt and Learn
Chapter 20 Ten Promising Treatments for the Future
Correcting Developmental Disorders through Gene Therapy
Augmenting the Brain with Genetic Manipulation
Correcting Brain Injury with Stem Cells
Using Deep Brain Stimulation to Treat Neurological Disorders
Stimulating the Brain Externally through TMS and tDCS
Using Neuroprostheses for Sensory Loss
Addressing Paralysis with Neuroprostheses
Building a Better Brain through Neuroprostheses
Engaging in Computer-Controlled Learning
Treating Disease with Nanobots
Glossary
Index
EULA