Biological and Cognitive Psychology
Physiology of Behavior
Vrije Universiteit Amsterdam
Semester 1, Period 2
Chapter 1
Neurogenesis: generation of new neurons
Scientific explanation takes two forms
(1) Generalization: refers to examples as general laws, revealed through
experiments
(2) Reduction: refers to explanations of complex phenomena in terms of simpler
ones
Research efforts of behavioral neuroscience involve both forms of explanation
Mind-body question: centered around what role the mind plays – two approaches
(1) Dualism: belief in the dual nature of reality; mind and body are separate
(2) Monism: belief that everything in the universe consists of matter and energy and
that the mind is a phenomenon produced by the working of the nervous system
Discoveries that have contributed to the field of behavioral neuroscience
Ancient world
Surgical records in ancient Egypt
Heart considered seat of thought and emotions > Hippocrates concluded that
this role should be assigned to the brain < Aristotle didn’t agree
Galen considered Aristotle’s theory not true
Seventeenth century
René Descartes: dualist, animals/humans are behavioral devices; their
behavior controlled by environmental stimuli
Reflexes: automatic reactions to stimuli
Descartes was first one to suggest that the mind controls the movements of
the body, while the body supplies the mind with information about the
environment
Brain contains hollow chambers filled with fluid, which flowed from the
brain into the appropriate set of nerves causing muscles to inflate and
move
Luigi Galvani disproved Descartes: found that electrical stimulation of a nerve
caused muscle contraction even when nerve and muscle were detached from
the rest of the body
Nineteenth century
Doctrine of specific nerve energies – Johannes Müller: although all nerves
carry the same basic message, we perceive the messages of different nerves
in different ways > set the stage for performing direct experiments on the
brain
Experimental ablation – Pierre Flourens: removal of various parts of animals’
brains and observe what the animal could no longer do > infer function of
missing portion
Broca did this post-mortem with human patients > Broca’s area
Gustav Fritsch and Eduard Hitzig: electrical stimulation of different portions of
a specific region of the brain caused contractions of specific muscles on the
opposite side of the body
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, Hermann von Helmholtz: first scientist to measure the speed of conduction
through nerves – 90 feet per second
Jan Purkinje: discovered Purkinje fibers – neurons terminating on cardiac cells
responsible for controlling heart contractions
Ramon Santiago y Cajal: proposed that the nervous system consisted of
billions of discrete, individual neurons, as opposed to the predominant
continuous idea
Contemporary research
Optogenetics, treatment of psychological disorders, refined understanding of
structures and functions of the brain
Society for Neuroscience: professional organization for scientists and physicians,
field strives to increase diversity
Functionalism – Charles Darwin: belief that characteristics of living organisms
perform useful functions – to understand the workings of something, we should
know what its functions are
Natural selection: characteristics that permit an individual to produce more
successfully will be inherited by its offspring > characteristics become more
prevalent in species
Artificial selection: controlled by animal breeders
Mutations: accidental changes in chromosomes of sperm or eggs that join together
and develop into new organisms
Small percentage is beneficial: selective advantage to organism that
possesses them
Traits altered by mutations are physical, but effects can be seen in behavior
Variety is definite advantage for species
Evolution: gradual change in structure and physiology of plant and animal species
as a result of natural selection
Brain has an abundance of neural circuits at birth, which can be seen as a
general-purpose, programmable computer
Bigger bodies require bigger brains, although the size of the brain does not
have to
Brains vary in size and number of neurons found in each gram of tissue
Slowing of the process of brain developments allows more time for growth –
genetic change responsible for evolution of the human brain
Neoteny: prolongation of maturation of the brain
In the US, any institution that receives federal funding to use animals in research is
required to have an Institutional Animal Care and Use Committee (IACUC): reviews
all proposals for research involving animals with the intent of ensuring humans and
ethical treatment
Approval ensures animal welfare and compliance with local, state, and
federal regulations
Use of animals in research is indispensable
Institutional Review Board (IRB) ensures ethical treatment of humans in research
Informed consent: researchers must inform any potential participant about
the nature of the study, data collection and storage methods, and anticipated
benefits and costs of participating
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, Neuroethics: devoted to better understanding implications of and developing
best practices in ethics for neuroscience research with human participants
Behavioral neuroscientists: study all behavioral phenomena that can be observed in
humans and animals – the role of the nervous system, interacting with the rest of
the body in controlling behavior
Chapter 2
Nerves: bundles of thousands of individual neurons wrapped in protective
membrane through which the CNS communicates with the rest of the body
Sensory nerves: collect information – PNS – about the environment
Motor neurons: – PNS – conduct movement through muscle contraction
Interneurons: neurons that lie entirely within the CNS
Local interneurons: form circuits with nearby neurons and analyze small
pieces of information
Relay interneurons: connect circuits of local interneurons in one region of the
brain with those in other regions
Axoplasmic transport: active process that propels substances along microtubule
‘tracks’ that run inside the length of an axon – process separate from the movement
of an action potential
Anterograde axoplasmic transport: movement from the soma to the terminal
buttons – accomplished by kinesin molecules – protein
Retrograde axoplasmic transport: carrying of substances from the terminal buttons
to the soma – accomplished by dynein protein < slower than anterograde transport
Membrane: boundary of a neuron – double layer of lipid molecules
Cytoskeleton: interior of a neuron which contains a matrix of strands of protein –
gives neuron its shape
Microtubules: thickest of the three protein strands the cytoskeleton is made
up of, bundles of thirteen protein filaments arranged around a hollow core
Cytoplasm: jellylike, semiliquid substance that fills the space outlined by the
membrane – contains organelles
Nucleus: round or oval structure found in the soma
Nucleolus: responsible for ribosome production – small structures involved in
protein synthesis
Chromosomes: consist of DNA strands – when they are active, portions of the
chromosomes that are active, genes, cause mRNA production < leaves the
nuclear membrane and attaches to ribosomes
Two-step process of protein production
(1) Transcription – information from DNA > mRNA, which takes it to ribosomes
(2) Translation – ribosomes use information from mRNA to create proteins
Enzymes: direct the chemical processes of a cell by controlling chemical reactions –
special protein molecules that act as catalysts
Endomembrane system in cells
Endoplasmic reticulum: appears rough and smooth; parallel layers of the same
membrane that encloses the cell, contains ribosomes
Unattached ribosomes produce protein for use within the neuron
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, Rough: contains ribosomes, protein produced by ribosomes attached to this
reticulum are destined to be transported out of the cell or used in the
membrane
Smooth: provides channels for the segregation of molecules involved in
various cellular processes
Golgi apparatus: assembles complex molecules, made up of simpler
individual molecules, serves as wrapping or packaging agent
Exocytosis: membrane-wrapped product migrates to the inside
of the outer membrane of the cell, fuses with the membrane,
and bursts, spilling contents into the fluid surrounding the cell <
manner in which neurons communicate
Lyosome production: small sacks that contain enzymes that
break down substances no longer needed by the cell
Mitochondria: oval beads formed from a double membrane, fulfills role in energy
extraction from breakdown of nutrients
> Cells provide mitochondria with nutrients, and mitochondria provide cells with
adenosine triphosphate (ATP)
Supporting cells of the CNS
Glia – glial cells: surround neurons and hold them in place; isolate them from one
another so messages do not get scrambled; destroy and remove carcasses of dead
neurons
Astrocytes: provide physical support to neurons and clean up debris within
the brain, control chemical composition of fluid surrounding neurons, provide
nourishment to neurons – glucose received from capillaries > broken down
into lactate > lactate is used for energy
In addition, they store glycogen that can be broken down to glucose for
energy
Engage in phagocytosis: engulfing and digesting debris of dead
neurons > once done, specialized kind will transform into scar tissue
Oligodendrocytes: provide support to axons and produce myelin sheath in the
Microglia: act as phagocytes, protect the brain from invading microorganisms
and are responsible to the inflammatory reaction in response to brain
damage
Supporting cells of the PNS
Schwann cells: perform the same function as the oligodendrocytes, one cell
provides myelin for one axon – if damage occurs to a nerve, Schwann cells aid in
digestion of dying axons, then they arrange themselves in a series of cylinders that
act as guides for axon regrowth > severed axons grow sprouts which and
connection is reestablished when the two encounter each other
There is a difference in regenerative properties of axons in the CNS and the PNS
resulting from differences in the characteristics of supporting cells, not from
differences in the axons
Immune system of someone with MS only attacks the myelin protein
produced by the oligodendrocytes
Blood-brain barrier: walls of capillaries ensuring barrier between the blood and the
fluid that surrounds the cells of the brain > selectively-permeable
Makes is easier to regulate the composition of extracellular fluid
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