Neuroscience
Chapter 1: Introduction
1.1 What is Neuroscience?
study of the nervous system and the way the brain performs its many functions
neurons - main active cellular units of the nervous system, are highly sensitive to changes in their
environment
o temporarily change their electric properties during an action potential, which allows for the
release of neurotransmitters
brains are flexible and the origin of consciousness
1.2 How do we learn about Neuroscience?
experimental design
o good experiment establishes causality between an independent variable and a dependent
variable by eliminating the influence of confounding variables
Observational study
o Quasiexperimental design
▪ do not benefit from separation of patients into groups randomly, and therefore may
have several uncontrolled variables
▪ usually done when conducting an experimental study may be too impractical or
otherwise unethical
▪ only show correlation, not causation
Case Study
o helpful for the development of hypotheses that can later be tested experimentally.
1.3 What Neuroscience is NOT
We don’t use just 10 % of our brains
o A fully-functioning brain uses nearly 100% of the component parts, but at precisely
controlled times, like a traffic light
Forming memories does not cause new neurons to be born
o memories are stored at synapses
o Changes in in ways neurons connect and communicate with one another is likely the
mechanism behind how memories are formed and stored
o The weight / neurogenesis of the brain does not increase much beyond the teen years, but
we continue to learn throughout the rest of our lives
The brain does indeed repair itself
o Brain plasticity - if critical brain areas are damaged brain is figuring out how to carry out
functions without using the damaged connections
o However, neurodegenerative conditions & disorders exist
Left-right brain distinction
, o nearly every function that the left half of the brain can do, the right half can do just as well,
and vice versa
o except for language, heavily lateralized in the left hemisphere for most people
o also: vertebrate nervous system likely twists in development, resulting in a contralateral
organization
1.4 Neuroscience is ever changing
Egyptians: disregarded function of brain
Greeks: function of the brain was to cool the blood as the blood passed through it, which calmed the
temper
Mid-19th century: Broca was one of the first to suggest that specific areas of the brain were
responsible for carrying out specific functions (localization theory)
o E.g: language comprehension starts in a small patch of cells in the left hemisphere (broca’s
area); perception of faces relies on a set of cells at the base of the brain; balance and motor
coordination depends on the cerebellum
o distributive processing theory - behavioral functions require activation of cells across
several different areas of the brain
▪ Complex behaviors such as emotion, consciousness, or cognition require
coordinated action across distinct brain areas
▪ cognition - the act of generating knowledge through a combination of senses,
memories, and thoughts
early 20 century: neurons had different shapes and therefore carried out different functions
th
o foundation for understanding the cells that make up the nervous system and the way they
communicate with one another
1950 - today: scientific advancements
o electron microscope - gives resolution to visualize the synapse, the tens of nanometer
distance between two neurons
o functional magnetic resonance imaging device (fMRI) - visualize brain activity while a person
is actively engaged in behaviors
o CLARITY - method to render an entire brain transparent, helps to map out the nature of the
connections that span the nervous system
1.5 Neuroscience is an integrative field of study
Biology
o Molecular neurobiologists study proteins and gene regulation
o cellular neurobiologists examine how networks of neurons communicate with one another
o cognitive neuroscientists study the underlying causes of behaviors
o genetics, ecology, evolution considered in neuroscience as well
o bottom-up approach
Psychology
o mind-body problem
o emergence - idea that the whole is greater than the sum of its parts
o top-down approach
Chemistry
o strong influencer of nervous system function
, o We use a variety of endogenous (originating from within the body) chemicals that act as
signaling molecules
o Some are acidic while others are basic; some are polar, others are fat soluble, and some are
even gases
o nervous system is also highly sensitive to influence by exogenous chemicals
Physics
o Action potential of neurons
computational neuroscience
o mathematical modeling to describe or predict some aspect of the nervous system
o 86 billion neurons in the brain
Healthcare providers & Engineers
o Develop and make use of assessment tools (CT scans, EEG, fMRI)
Chapter 2: Anatomy of the Nervous System
2.1 Central Nervous System (CNS)
brain and spinal cord
2% of body weight, but 20% energy uptake
Information that arrives into the CNS is an afferent signal, while information leaving the CNS is an
efferent signal
Anatomical language of the brain
Brain directions:
o Rostral/anterior = forward, front/before
o Caudal/posterior = Backward/after
o Dorsal/superior = Top
o Ventral/inferior = Bottom
o Medial = closer to center
o Lateral = closer to sides
Visualizing the brain
white matter represents pathways of communication
, o several layers of fatty lipids (myelin) for neurons to send signals quickly
gray matter is usually dense with cell bodies
corpus callosum, major communication tract between the left and right hemispheres.
o decussation: information passes between both hemispheres via white matter
Brain structures through development
When the embryo first starts to form, cells are classified into three main germ layers
o Ectoderm
▪ eventually develops into the nervous system
▪ folds into itself, creates the neural tube
o Mesoderm
o Endoderm
Early in development, the neural tube has three distinct compartments
o undeveloped nervous system is appropriately called the “three-vesicle stage.”
o One week later Rhombencephalon, or hindbrain “five-vesicle stage.”
Rhombencephalon, or hindbrain
o Oldest part
o basic survival, such as respiration and simple locomotion
o Myelencephalon
▪ develops into the medulla oblongata
▪ responsible for unconscious functions, such as breathing or changes in heart rate
and blood pressure
▪ can detect toxins in the blood and triggers vomiting
o Metencephalon
▪ Pons
• helps us perform involuntary functions like breathing
• hear sounds and taste foods
▪ Cerebellum
Chapter 1: Introduction
1.1 What is Neuroscience?
study of the nervous system and the way the brain performs its many functions
neurons - main active cellular units of the nervous system, are highly sensitive to changes in their
environment
o temporarily change their electric properties during an action potential, which allows for the
release of neurotransmitters
brains are flexible and the origin of consciousness
1.2 How do we learn about Neuroscience?
experimental design
o good experiment establishes causality between an independent variable and a dependent
variable by eliminating the influence of confounding variables
Observational study
o Quasiexperimental design
▪ do not benefit from separation of patients into groups randomly, and therefore may
have several uncontrolled variables
▪ usually done when conducting an experimental study may be too impractical or
otherwise unethical
▪ only show correlation, not causation
Case Study
o helpful for the development of hypotheses that can later be tested experimentally.
1.3 What Neuroscience is NOT
We don’t use just 10 % of our brains
o A fully-functioning brain uses nearly 100% of the component parts, but at precisely
controlled times, like a traffic light
Forming memories does not cause new neurons to be born
o memories are stored at synapses
o Changes in in ways neurons connect and communicate with one another is likely the
mechanism behind how memories are formed and stored
o The weight / neurogenesis of the brain does not increase much beyond the teen years, but
we continue to learn throughout the rest of our lives
The brain does indeed repair itself
o Brain plasticity - if critical brain areas are damaged brain is figuring out how to carry out
functions without using the damaged connections
o However, neurodegenerative conditions & disorders exist
Left-right brain distinction
, o nearly every function that the left half of the brain can do, the right half can do just as well,
and vice versa
o except for language, heavily lateralized in the left hemisphere for most people
o also: vertebrate nervous system likely twists in development, resulting in a contralateral
organization
1.4 Neuroscience is ever changing
Egyptians: disregarded function of brain
Greeks: function of the brain was to cool the blood as the blood passed through it, which calmed the
temper
Mid-19th century: Broca was one of the first to suggest that specific areas of the brain were
responsible for carrying out specific functions (localization theory)
o E.g: language comprehension starts in a small patch of cells in the left hemisphere (broca’s
area); perception of faces relies on a set of cells at the base of the brain; balance and motor
coordination depends on the cerebellum
o distributive processing theory - behavioral functions require activation of cells across
several different areas of the brain
▪ Complex behaviors such as emotion, consciousness, or cognition require
coordinated action across distinct brain areas
▪ cognition - the act of generating knowledge through a combination of senses,
memories, and thoughts
early 20 century: neurons had different shapes and therefore carried out different functions
th
o foundation for understanding the cells that make up the nervous system and the way they
communicate with one another
1950 - today: scientific advancements
o electron microscope - gives resolution to visualize the synapse, the tens of nanometer
distance between two neurons
o functional magnetic resonance imaging device (fMRI) - visualize brain activity while a person
is actively engaged in behaviors
o CLARITY - method to render an entire brain transparent, helps to map out the nature of the
connections that span the nervous system
1.5 Neuroscience is an integrative field of study
Biology
o Molecular neurobiologists study proteins and gene regulation
o cellular neurobiologists examine how networks of neurons communicate with one another
o cognitive neuroscientists study the underlying causes of behaviors
o genetics, ecology, evolution considered in neuroscience as well
o bottom-up approach
Psychology
o mind-body problem
o emergence - idea that the whole is greater than the sum of its parts
o top-down approach
Chemistry
o strong influencer of nervous system function
, o We use a variety of endogenous (originating from within the body) chemicals that act as
signaling molecules
o Some are acidic while others are basic; some are polar, others are fat soluble, and some are
even gases
o nervous system is also highly sensitive to influence by exogenous chemicals
Physics
o Action potential of neurons
computational neuroscience
o mathematical modeling to describe or predict some aspect of the nervous system
o 86 billion neurons in the brain
Healthcare providers & Engineers
o Develop and make use of assessment tools (CT scans, EEG, fMRI)
Chapter 2: Anatomy of the Nervous System
2.1 Central Nervous System (CNS)
brain and spinal cord
2% of body weight, but 20% energy uptake
Information that arrives into the CNS is an afferent signal, while information leaving the CNS is an
efferent signal
Anatomical language of the brain
Brain directions:
o Rostral/anterior = forward, front/before
o Caudal/posterior = Backward/after
o Dorsal/superior = Top
o Ventral/inferior = Bottom
o Medial = closer to center
o Lateral = closer to sides
Visualizing the brain
white matter represents pathways of communication
, o several layers of fatty lipids (myelin) for neurons to send signals quickly
gray matter is usually dense with cell bodies
corpus callosum, major communication tract between the left and right hemispheres.
o decussation: information passes between both hemispheres via white matter
Brain structures through development
When the embryo first starts to form, cells are classified into three main germ layers
o Ectoderm
▪ eventually develops into the nervous system
▪ folds into itself, creates the neural tube
o Mesoderm
o Endoderm
Early in development, the neural tube has three distinct compartments
o undeveloped nervous system is appropriately called the “three-vesicle stage.”
o One week later Rhombencephalon, or hindbrain “five-vesicle stage.”
Rhombencephalon, or hindbrain
o Oldest part
o basic survival, such as respiration and simple locomotion
o Myelencephalon
▪ develops into the medulla oblongata
▪ responsible for unconscious functions, such as breathing or changes in heart rate
and blood pressure
▪ can detect toxins in the blood and triggers vomiting
o Metencephalon
▪ Pons
• helps us perform involuntary functions like breathing
• hear sounds and taste foods
▪ Cerebellum
