review the ppt then answer the quiz 1
PSY 210 – QUIZ 1
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1. Structures located relatively toward the tail of a four-legged animal are referred to as
a.
rostral.
b.
caudal.
c.
dorsal.
d.
ventral.
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2. Structures located relatively toward the belly of a four-legged animal are referred to as
a.
rostral.
b.
caudal.
c.
dorsal.
d.
ventral.
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3. A dog’s ears are __________ relative to its tail.
a.
rostral
b.
caudal
c.
dorsal
d.
ventral
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4. Which of the following pairs of terms mean the same thing?
a.
ventral—superior
b.
dorsal—inferior
c.
rostral—anterior
d.
caudal—ipsilateral
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5. An imaginary line that runs the length of the spinal cord to the front of the brain is known as the
a.
sagittal slice.
b.
proximal.
c.
neuraxis.
d.
plane of section.
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6. The most common type of glia in the brain is the
a.
astrocyte.
b.
oligodendrocyte.
c.
Schwann cell.
d.
microglia.
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7. A structural matrix for neurons is provided by
a.
astrocytes.
b.
oligodendrocytes.
c.
Schwann cells.
d.
microglia.
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8. The glia that participate in the formation of the blood-brain barrier are the
a.
astrocytes.
b.
oligodendrocytes.
c.
Schwann cells.
d.
microglia.
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9. An important function of the astrocytes is to regulate the chemical environment of the synaptic gap. In particular, the astrocytes remove excess amounts of which of the following chemicals from the gap?
a.
magnesium
b.
potassium
c.
sodium
d.
tetrodotoxin
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10. Following injury, which of the glia may actually inhibit neural regrowth by forming scar tissue?
a.
astrocytes
b.
oligodendrocytes
c.
Schwann cells
d.
microglia
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11. Which of the following thinkers believed that the ventricles played an important role in transmitting information to and from the brain?
a.
Aristotle
b.
Galen
c.
Descartes
d.
Herophilus
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12. What mistaken notion about the nervous system persisted from ancient times up through the work of some Renaissance thinkers?
a.
The ventricles play a major role in the transmission of messages in the brain.
b.
The heart is the organ of intellect.
c.
Damage to the brain is easily repaired.
d.
The muscular tremors that characterize epilepsy do not originate in the brain.
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13. Monism is defined as a philosophical view that considers
a.
mind to be the product of activity in the brain.
b.
mind and body to be separate entities.
c.
the senses as the source of knowledge.
d.
reality to exist when it enters the thinking of an observer.
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14. According to Descartes, the mind
a.
is the product of neural activity.
b.
exists in both human and non-human animals.
c.
forms an indivisible whole with the body.
d.
is not a physical entity that can be studied.
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15. Descartes’ mind-body dualism is defined as a philosophical view that considers
a.
mind to be the product of neural activity.
b.
mind and body to be separate entities.
c.
reality to exist only when perceived by an observer.
d.
the senses as the source of knowledge.
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16. Rob and his friends were experimenting with the hallucinogenic Amanita mushrooms, and he experienced a sudden drop in blood pressure. Which of the following is the best explanation for Rob’s symptoms?
a. The muscarine in the mushrooms interacted with dopaminergic receptors in Rob’s peripheral nervous system.
b. The nicotine in the mushrooms interacted with cholinergic receptors in Rob’s central nervous system.
c. The muscarine in the mushrooms interacted with cholinergic receptors in Rob’s peripheral nervous system.
d. The muscarine in the mushrooms interacted with cholinergic receptors in Rob’s central nervous system.
17. Muscarinic receptors respond to
a. muscarine, a substance found in tobacco, and acetylcholine.
b. muscarine, a substance found in some mushrooms, and acetylcholine.
c. muscarine, nicotine, and acetylcholine.
d. acetylcholine only.
18. Which of the following statements about nicotinic and muscarinic receptors is true?
a. Nicotinic receptors are ionotropic, whereas muscarinic receptors are metabotropic.
b. Nicotinic receptors are metabotropic, whereas muscarinic receptors are ionotropic.
c. Nicotinic and muscarinic receptors are both ionotropic.
d. Nicotinic and muscarinic receptors are both metabotropic.
19. Which of the following statements accurately describes the locations of muscarinic and nicotinic receptors?
a. Muscarinic and nicotinic receptors are found in both the central and peripheral nervous systems.
b. Muscarinic receptors are found in the central nervous system only, whereas nicotinic receptors are found in the peripheral nervous system only.
c. Nicotinic receptors are found in both the central and peripheral nervous systems, whereas muscarinic receptors are found in the central nervous system only.
d. Muscarinic receptors are found in both the central and peripheral nervous systems, whereas nicotinic receptors are found in the central nervous system only.
20. Jessica is worried about the impact of her smoking habit on her health. After studying biological psychology, she knows that nicotine would have an effect on
a. her peripheral nervous system only.
b. her central nervous system only.
c. both her peripheral and central nervous systems.
d. neither her peripheral nor central nervous systems, because she only smokes a couple of cigarettes with friends during weekend parties.
© Cengage Learning 2016
© Cengage Learning 2016
What is Behavioral Neuroscience?
Chapter One
© Cengage Learning 2016
• Neuroscience
– “The scientific study of the brain and nervous
system, in health and in disease” (UCLA,
2000)
– Incorporates the fields of psychology, biology,
chemistry, medicine, mathematics, physics,
engineering, and computer science
Neuroscience as an Interdisciplinary Field
© Cengage Learning 2016
• The functions of the brain and nervous
system are studied on many different
levels
From Molecules to Behavior
© Cengage Learning 2016
• Ancient milestones
– Trepanation
– Egyptian medical papyrus; mummification
– Ancient Greeks: Hippocrates, Galen
• The dawn of scientific reasoning
– Descartes (1596-1650): mind-body dualism
– Van Leeuwenhoek
– Galvani and du Bois-Reymond
– Bell and Magendie
Historical Highlights in Neuroscience
© Cengage Learning 2016
Prehistoric Brain Surgery
© Cengage Learning 2016
Galvani – the Role of Electricity in Neural
Communication
© Cengage Learning 2016
• Santiago Ramón y Cajal and Camillo Golgi
– The Neuron Doctrine
• Gall and Spurzheim: phrenology
• Paul Broca
• Fritsch and Hitzig
• John Hughlings-Jackson (1835-1911)
– Founding of modern neuroscience
• Sherrington, Loewi, Eccles, Katz, Huxley,
Hodgkin
Modern Neuroscience Begins
© Cengage Learning 2016
Phrenology Bust
© Cengage Learning 2016
• The study of microscopic structures and
tissues
• Provides the means for observing
structure, organization, and connections of
individual cells
• Tissue fixation, microtome machine, and
specialized stains
Behavioral Neuroscience Research
Methods – Histology
© Cengage Learning 2016
Tissue Sectioning using a Microtome
© Cengage Learning 2016
• Examination of the body after death
• Correlational method that must be
interpreted carefully and precisely
Behavioral Neuroscience Research
Methods – Autopsy
© Cengage Learning 2016
• Types of imaging technologies
– Computerized tomography (CT)
– Positron emission tomography (PET)
– Magnetic resonance imaging (MRI)
• Functional MRI (fMRI)
• Diffusion tensor imaging (DTI)
• Advantage of imaging over autopsy
– Can watch the living brain as it behaves
Behavioral Neuroscience Research
Methods – Imaging
© Cengage Learning 2016
CT Scans – Historical and Modern
© Cengage Learning 2016
PET Scans Show Patterns of Brain
Activation
© Cengage Learning 2016
Functional MRI (fMRI) Tracks Cerebral
Blood Flow
© Cengage Learning 2016
Diffusion Tensor Imaging (DTI) Constructs
Maps of the Brain’s Fiber Pathways
© Cengage Learning 2016
• Records electrical and magnetic output
from the brain
– Electroencephalogram (EEG)
– Event-related potentials
–
Magnetoencephalography (MEG)
– Single-cell recordings
Recording
© Cengage Learning 2016
Event-Related Potentials (ERPs)
© Cengage Learning 2016
Magnetoencephalography (MEG)
© Cengage Learning 2016
• Artificial stimulation of specific brain
regions and observation of resulting
behavior
– Surface electrodes during neurosurgery
– Surgically implanted electrodes
– Repeated transcranial magnetic stimulation
(rTMS)
– Optogenetics
Brain Stimulation
© Cengage Learning 2016
Deep Brain Stimulation and rTMS
© Cengage Learning 2016
• Lesion: injury to neural tissue
• Naturally occurring
• Deliberately produced
• Ablation
– Surgical removal of neural tissue
Lesions
© Cengage Learning 2016
• Biochemical methods
– Use of chemical stimulation and microdialysis
• Genetic methods
– Twin studies (concordance rates)
– Adoption studies (heritability)
– Studies of genetically-modified animals
(knockout genes)
– Epigenetics (gene expression due to external
factors)
Other Research Methods
© Cengage Learning 2016
• Stem cells
– Undifferentiated cells that can divide and
differentiate into other types of cells
– One of the most promising approaches to
understanding neural development,
regeneration, and disease
– Embryonic or adult: advantages and
disadvantages of both
– Can be used to repair the nervous system
Other Research Methods (cont’d.)
© Cengage Learning 2016
• Mechanisms for protection of human
participants and animal research subjects
– Hippocrates
– Federal government and the Common Rule
– University review and institutional review
boards
Research Ethics in Behavioral
Neuroscience
© Cengage Learning 2016
• Coercion of research participants is
unacceptable
• Benefits to participants should not be
“excessive or inappropriate”
• Participants must be informed that they
can leave without penalty at any time
• Participants must be told enough about
the experiment to make an informed
decision about participating
Research Ethics – Human Participants
© Cengage Learning 2016
• Participants must receive contact
information in case they have questions
• Participants must be assured their data
will be confidential
Research Ethics – Human Participants
(cont’d.)
© Cengage Learning 2016
• Animal research should have a clear
scientific purpose
• Excellent care and housing should be
provided
• Experimental procedures should cause as
little pain and distress as possible
Research Ethics – Animal Subjects
© Cengage Learning 2016
© Cengage Learning 2016
Functional Neuroanatomy and the
Evolution of the Nervous System
Chapter Two
© Cengage Learning 2016
• Rostral or anterior
– Head end of four legged animal
• Caudal or posterior
– Tail end of four legged animal
• Inferior or ventral
– Towards the belly
• Superior or dorsal
– Towards the back
Anatomical Directions
© Cengage Learning 2016
Anatomical Directions (cont’d.)
© Cengage Learning 2016
• Sagittal
– Parallel to midline
• Coronal
– Divides nervous system front to back
• Horizontal
– (axial, transverse)
– Divides brain from top to bottom
Planes of Section
© Cengage Learning 2016
Planes of Section (cont’d.)
© Cengage Learning 2016
• Meninges
– Three layers of meninges provide protection
• Cerebrospinal fluid
– Secreted in hollow spaces in the brain known
as ventricles
– Circulates through ventricles, subarachnoid
space, and central canal of the spinal cord
• Blood supply
– Brain receives nutrients through the carotid
arteries and vertebral arteries
Protecting and Supplying the Nervous
System
© Cengage Learning 2016
The Skull and Three Layers of Membrane
Protect the Brain
© Cengage Learning 2016
Cerebrospinal Fluid Circulation
© Cengage Learning 2016
Hydrocephalus
© Cengage Learning 2016
The Brain Has a Generous Supply of Blood
© Cengage Learning 2016
• The central nervous system
– Brain and spinal cord
• The peripheral nervous system
– All nerves that leave from the brain and spinal
cord and extend to and from all parts of the
body
The Organization of the Nervous System
© Cengage Learning 2016
The Organization of the Nervous System
© Cengage Learning 2016
• Anatomy
– Extends from the medulla to the first lumbar
vertebra
– 31 spinal nerves (cervical, thoracic, lumbar,
sacral, coccygeal)
– White matter (nerve fibers); gray matter (cell
bodies)
• Reflexes
– Patellar reflex
– Withdrawal reflex
The Central Nervous System –
The Spinal Cord
© Cengage Learning 2016
The Anatomy of the Spinal Cord
© Cengage Learning 2016
Embryological Divisions of the Brain
© Cengage Learning 2016
Structures of the Brainstem
© Cengage Learning 2016
Structures of the Brainstem (cont’d.)
© Cengage Learning 2016
• Medulla (myelencephalon)
– Breathing, heart rate, blood pressure
– Reticular formation
• Consciousness, arousal, movement, and pain
• Metencephalon
– Pons: balance, motion sickness
– Cerebellum
• Voluntary movements, muscle tone, balance,
speech, motion sickness, executive functions, and
emotional processing
The Central Nervous System: The
Hindbrain
© Cengage Learning 2016
• Periaqueductal gray
– Natural pain management
• Red nucleus
– Motor output pathway
• Substantia nigra
– Motor output pathway
– Parkinson’s disease
• Superior and inferior colliculi
– Visual and auditory stimuli
The Internal Structure of the Midbrain
© Cengage Learning 2016
The Internal Structure of the Midbrain
© Cengage Learning 2016
Important Structures in the Brainstem
© Cengage Learning 2016
• The forebrain is composed of the
diencephalon and the telencephalon
• Diencephalon
– Thalamus
• Receives sensory input
– Hypothalamus
• Regulation of the endocrine system
The Central Nervous System –
The Forebrain
© Cengage Learning 2016
The Thalamus and Hypothalamus of the
Diencephalon
© Cengage Learning 2016
• Telencephalon
– Basal ganglia
• Motor control
• Parkinson’s and Huntington’s disease; ADHD
– Limbic sstem
• Learning, motivated behavior, and emotion
– Cerebral
cortex
• Four lobes
• Sensory cortex, motor cortex, and association
cortex
The Central Nervous System –
The Forebrain (cont’d.)
© Cengage Learning 2016
The Basal Ganglia and the Limbic System
© Cengage Learning 2016
Structures of the Limbic System
© Cengage Learning 2016
The Hippocampus
© Cengage Learning 2016
Comparative Convolutions of the Cortex
© Cengage Learning 2016
The Layers of the Cerebral Cortex
© Cengage Learning 2016
Brodmann’s Map of the Brain
© Cengage Learning 2016
The Lobes of the Cerebral Cortex
© Cengage Learning 2016
The Corpus Callosum and the Anterior
Commissure
© Cengage Learning 2016
• Frontal lobe
– Primary motor cortex, cognitive processes
– Dorsolateral prefrontal cortex, orbitofrontal
cortex
– Phineas Gage
– Lobotomies
– Broca’s area
– Lateralization of function
Localization of Function in the Cortex
© Cengage Learning 2016
The Case of Phineas Gage
© Cengage Learning 2016
• The Human Connectome Project
– Mapping the neural connections within the
brain
– Cellular and macro levels of investigation
Brain Circuits and the Connectome
© Cengage Learning 2016
• The cranial nerves
– Enter and exit the brain directly to serve the
region of the head and neck
• The spinal nerves
– 31 pairs provide sensory and motor pathways
to the torso, arms, and legs
– Mixed nerves (afferent and efferent)
• The autonomic nervous system
– Manages the vital functions of the body
without conscious effort or awareness
The Peripheral Nervous System
© Cengage Learning 2016
The Twelve Pairs of Cranial Nerves
© Cengage Learning 2016
The Structure of the Spinal Cord
© Cengage Learning 2016
• The sympathetic nervous system
– Fight-or-flight system
• The parasympathetic nervous system
– Provides rest, repair, and energy storage
• The enteric nervous system
– Serves the gastrointestinal tract
• The endocrine system
– Hypothalamic control of hormone release
– Pituitary gland
The Autonomic Nervous System
© Cengage Learning 2016
The Sympathetic and Parasympathetic
Nervous Systems
© Cengage Learning 2016
• Natural selection and evolution
– Natural selection favors the organism with the
highest degree of fitness
• Evolution of the nervous system
– Fairly recent; vertebrates or chordates are
animals with spinal columns and real brains
• Evolution of the human brain
– Outstanding modern feature is our brain size
– Brain development occurred very recently
The Evolution of the Human Brain and
Nervous System
© Cengage Learning 2016
Timeline for the Evolution of the Brain
© Cengage Learning 2016
The Evolution of Chordate Brains
© Cengage Learning 2016
Human Brain Development Proceeded
Swiftly
© Cengage Learning 2016
© Cengage Learning 2016
Cells of the Nervous System
Chapter Three
© Cengage Learning 2016
• Glia
– Primary supporting cells of the CNS
• Macroglia (astrocytes, oligodendrocytes, Schwann
cells)
• Microglia
• Neurons
– Primary functioning cells of the CNS
– Information processing and communication
Glia and Neurons
© Cengage Learning 2016
• Macroglia
– Astrocytes, oligodendrocytes, Schwann cells
• Microglia
Glia Are Classified by Size
© Cengage Learning 2016
Astrocytes
© Cengage Learning 2016
Oligodendrocytes and Schwann Cells
© Cengage Learning 2016
• Phospholipid bilayer; ion channels/pumps
The Neural Membrane
© Cengage Learning 2016
• Microtubules, neurofilaments, and
microfilaments
The Cytoskeleton of Neurons –
Three Fiber Types
© Cengage Learning 2016
Tau Phosphorylation
© Cengage Learning 2016
• Site of synapses and organelles
The Neural Cell Body (Soma)
© Cengage Learning 2016
• Dendrites receive signals from adjacent
neurons
– Dendritic spines
• Axons transmit signals
– Axon hillock
– Myelination
– Nodes of Ranvier
– Axon terminal
Axons and Dendrites
© Cengage Learning 2016
Axons and Dendrites (cont’d.)
© Cengage Learning 2016
• Unipolar
– Single branch extending from the cell body
• Bipolar
– Two branches extending from the neural cell
body: one axon and one dendrite
– von Economo neurons
• Multipolar
– Many branches extending from the cell body;
usually one axon and many dendrites
Structural Variations in Neurons
© Cengage Learning 2016
• Sensory neurons
– Specialized to receive information from the
outside world
• Motor neurons
– Transmit commands from the CNS directly to
muscles and glands
• Interneurons
– Act as bridges between the sensory and
motor systems
Functional Variations in Neurons
© Cengage Learning 2016
Structural and Functional Classification of
Neurons
© Cengage Learning 2016
Structural and Functional Classification of
Neurons (cont’d.)
© Cengage Learning 2016
• An action potential is an electrical signal
that begins the process of neural
communication
• Ionic composition of the intracellular and
extracellular fluids
– Differs in the relative concentrations of ions
inside vs. outside the cell
– The difference in ion composition between
these fluids provides the neuron with a source
of energy for electrical signaling
Generating Action Potentials
© Cengage Learning 2016
• Voltage difference across the resting
membrane = 70mV
• Extracellular environment is assigned a
value of 0
• Therefore, the resting potential = -70mV
Resting Potential
© Cengage Learning 2016
The Composition of Intracellular and
Extracellular Fluids
© Cengage Learning 2016
Measuring the Resting Potential
of Neurons
© Cengage Learning 2016
• Diffusion
– Molecules move from areas of high
concentration to areas of low concentration
(along a concentration gradient)
• Electrostatic pressure
– Like-signed ions repel each other
– Opposite-signed ions move toward each other
The Generation of the Action Potential:
The Movement of Ions
© Cengage Learning 2016
• Resting potential averages -70mV
– Resting membrane is permeable to potassium
– Some sodium leaks into the cell
– Resting potential is maintained by controlling
the movement of potassium ions
Diffusion and Electrostatic Pressure
© Cengage Learning 2016
Diffusion and Electrostatic Pressure
(cont’d.)
© Cengage Learning 2016
• Depolarization
– Ion movement decreases the membrane
potential toward 0 mV
• The membrane potential must reach the threshold
of about -65mV to produce an action potential
– When the threshold is reached, voltage-gated
sodium ion channels open to allow sodium to
flow into the neuron
– Voltage-gated potassium ion channels open
near the peak of the action potential to allow
potassium to flow out of cell
The Action Potential – All-or-None
© Cengage Learning 2016
• Once the cell returns to the resting level, it
actually hyperpolarizes
– Overshoots its target and becomes even
more negative than when at rest
• Refractory period
– Membrane potential returns to resting
potential
– Absolute versus relative refractory periods
• The rate of neural firing varies to reflect
stimulus intensity
The Action Potential – All-or-None (cont’d.)
© Cengage Learning 2016
The Action Potential – The Sequence of
Events
© Cengage Learning 2016
• The signal reproduces itself down the
length of the axon
• Influenced by myelination
– Propagation in unmyelinated axon requires
reproduction of the action potential at each
successive axonal segment
– Propagation in myelinated axons requires
reproduction of the action potential in the
nodes of Ranvier: saltatory conduction
Propagating Action Potentials
© Cengage Learning 2016
Action Potentials Propagate Down the
Length of the Axon
© Cengage Learning 2016
Propagation in Unmyelinated and
Myelinated Axons
© Cengage Learning 2016
• The action potential is transmitted to the
adjacent postsynaptic neuron at the
synapse
Neurons Communicate at the Synapse
© Cengage Learning 2016
A Comparison of Electrical and Chemical
Synapses
© Cengage Learning 2016
The Electrical Synapse
© Cengage Learning 2016
• Neurotransmitters are released from the
presynaptic cell
• Neurotransmitters bind to postsynaptic
receptor sites
• The chemical signal is then terminated
The Chemical Synapse
© Cengage Learning 2016
Exocytosis Results in the Release of
Neurotransmitters
© Cengage Learning 2016
Ionotropic and Metabotropic Receptors
© Cengage Learning 2016
Methods for Deactivating Neurochemicals
© Cengage Learning 2016
• Small, local, graded potentials
• Excitatory (EPSPs) or inhibitory (IPSPs)
Postsynaptic Potentials
© Cengage Learning 2016
Neural Integration Combines Excitatory and
Inhibitory Input
© Cengage Learning 2016
• Axo-axonic synapses between an axon
terminal and another axon fiber have a
modulating effect on the release of
neurotransmitter by the target axon
Neuromodulation
© Cengage Learning 2016
© Cengage Learning 2016
Psychopharmacology
Chapter Four
© Cengage Learning 2016
• Neurotransmitters
– Participate in directed synapses by acting on
neurons in their own immediate vicinity
• Neuromodulators and neurohormones
– Participate in nondirected synapses by acting
on more distant neurons
– Neuromodulators communicate with target
diffuse away from the point of release
– Neurohormones travel in the blood supply to
reach their final targets
Neurotransmitters, Neuromodulators, and
Neurohormones
© Cengage Learning 2016
Neuromodulators and Neurohormones
© Cengage Learning 2016
• Substances released by one cell that
produce a reaction in a target cell
• The substance:
– Must be present within a presynaptic cell.
– Is released in response to presynaptic
depolarization
– Interacts with specific receptors on a
postsynaptic cell
Identifying Neurochemicals
© Cengage Learning 2016
Types of Neurochemicals
© Cengage Learning 2016
Features of Small-Molecules and
Neuropeptides
© Cengage Learning 2016
• Produced in cholinergic neurons
• Two receptor types:
– Nicotinic receptors
– Muscarinic receptors
Small-Molecule Neurochemicals:
Acetylcholine
© Cengage Learning 2016
The Distribution of Cholinergic Systems in
the Brain
© Cengage Learning 2016
• Catecholamines
– Dopamine, norepinephrine, epinephrine
– Synthesized from tyrosine
• Indoleamines
– Serotonin, melatonin
– Serotonin is synthesized from tryptophan
Small-Molecule Neurochemicals:
Monoamines
© Cengage Learning 2016
Catecholamines Share a Common
Synthesis Pathway
© Cengage Learning 2016
• Dopaminergic neurons in the midbrain
form connections with other neurons
• Dopamine activity is associated with
motivated behavior and reward processing
Dopaminergic Systems in the Brain
© Cengage Learning 2016
Dopaminergic Systems in the Brain (cont’d.)
© Cengage Learning 2016
• Norepinephrine
– Noradrenergic neurons
– Increases arousal and vigilance
– Primary neurotransmitter in the sympathetic
nervous system
• Epinephrine
– Adrenergic neurons
– Regulation of eating, blood pressure
Noradrenergic Systems in the Brain
© Cengage Learning 2016
Noradrenergic Systems in the Brain
(cont’d.)
© Cengage Learning 2016
• Synthesized from tryptophan
• Regulates mood, sleep, and appetite
Indoleamines: Serotonin
© Cengage Learning 2016
Serotonergic Pathways in the Brain
© Cengage Learning 2016
• Synthesized from histidine
• Associated with wakefulness
Histamine
© Cengage Learning 2016
• Major excitatory neurotransmitter in the
CNS
• Subtypes of glutamate receptors: NMDA,
AMPA, and kainate
Amino Acid Messengers: Glutamate
© Cengage Learning 2016
• Major inhibitory neurochemical in the CNS
• Synthesized from glutamate
• GABAA and GABAB receptors
– GABAA receptors interact with psychoactive drugs
Amino Acid Messengers: GABA
© Cengage Learning 2016
The GABAA Receptor Interacts with Several
Drugs
© Cengage Learning 2016
• Major inhibitory neurochemical in spinal
cord interneurons
• Excitatory function with glutamate at
NMDA receptors
• Synthesized from serine
Amino Acid Messengers: Glycine
© Cengage Learning 2016
• Act in the CNS and in connections
between autonomic neurons and the vas
deferens, bladder, heart, and gut
– ATP is associated with pain perception and
sleep-waking cycles
– Adenosine inhibits the release of many
neurochemicals
ATP and Adenosine
© Cengage Learning 2016
• Substance P (pain perception)
• Endorphins act on same receptors as
opioids and heroin
• Insulin and cholecystokinin function in
digestion and as neuromodulators and
neurohormones
• Oxytocin and vasopressin act as
neuromodulators and neurohormones
Neuropeptides
© Cengage Learning 2016
Distribution of Endorphin Receptors in the
Human Brain
© Cengage Learning 2016
• Diffuse through membranes and interact
with intracellular receptors
• Transmits information from the
postsynaptic to the presynaptic neurons
• Nitric oxide (NO)
– Neural communication, maintenance of blood
pressure, erection (target of Viagra)
Gasotransmitters
© Cengage Learning 2016
• Agonists enhance the activity of a
neurotransmitter
• Antagonists reduce the activity of a
neurotransmitter
Drug Actions at the Synapse
© Cengage Learning 2016
• Neurochemical production
– Manipulating the synthesis of a
neurotransmitter may affect the amount
available for release
• Neurochemical storage
– Interfering with the storage of a
neurotransmitters in vesicles within a neuron
• Neurochemical release
– Can be modified in response to the arrival of
an action potential by drugs
Mechanisms of Drug Actions at the
Synapse
© Cengage Learning 2016
• Mimic the action of a neurotransmitter at
the site
• Block the synaptic activity by occupying a
binding site
• Influence the activity of the receptor
Mechanisms of Drug Actions at the
Synapse: Receptor Effects
© Cengage Learning 2016
Drug Interactions at the Cholinergic
Synapse
© Cengage Learning 2016
Drug Interactions at the Dopaminergic
Synapse
© Cengage Learning 2016
Drug Interactions at the Serotonergic
Synapse
© Cengage Learning 2016
• Reuptake effects
– Cocaine, amphetamine, and Ritalin inhibit
dopamine reuptake
– SSRIs (e.g., Prozac) inhibit serotonin
reuptake
• Enzymatic degradation
– Organophosphates interfere with AChE
• Deactivation of neurotransmitters
Reuptake Effects and Enzymatic
Degradation
© Cengage Learning 2016
• Administration of drugs
– Method of administration leads to different
effects on nervous system; blood-brain barrier
• Individual differences
– Drug effects influenced by body weight,
gender, and genetics
• Placebo effects
– User expectations influence drug effects
– Double-blind experiment
Basic Principles of Drug Effects
© Cengage Learning 2016
Concentration of a Drug in the Blood Supply
Depends on the Method of Administration
© Cengage Learning 2016
• Tolerance
– Lessened effects as a result of repeated
administration
• Withdrawal
– Occurs when substance use is discontinued;
opposite of the effects caused by the
discontinued drug
• Addiction
– Compulsive need to use the drug repeatedly
despite harm to the user
Tolerance, Withdrawal, and Addiction
© Cengage Learning 2016
Vaccinations Against Drugs of Abuse
© Cengage Learning 2016
• Increase alertness and mobility
– Caffeine – adenosine antagonist
– Nicotine – nicotinic cholinergic receptor
agonist
– Cocaine – dopamine reuptake inhibitor
– Amphetamine – stimulates release and
inhibits reuptake of dopamine/norepinephrine
– Ecstasy (MDMA) – stimulates release of
serotonin and oxytocin; toxic to serotonergic
neurons
Effects of Psychoactive Drugs: Stimulants
© Cengage Learning 2016
Caffeine Content of Common Products
© Cengage Learning 2016
Caffeine Content of Common Products
(cont’d.)
© Cengage Learning 2016
Health Consequences of Methamphetamine
Abuse
© Cengage Learning 2016
Historical Use of Cocaine
© Cengage Learning 2016
Ecstasy Damages Serotonergic Neurons
© Cengage Learning 2016
• Interact with endorphin receptors
– Pain relief, relaxation, sense of euphoria
• Opiates
– Derived from sap of opium poppy
– Morphine, codeine
– Heroin
• Synthetic opiate
• Derived from morphine
Opioids
© Cengage Learning 2016
• Active ingredient THC is an endogenous
cannabinoid receptor agonist
• Cannabinoid receptors are in the
hippocampus and prefrontal cortex
• Effects: mild euphoria, perceptual
distortion, hallucination, and depression
Marijuana (Cannabis)
© Cengage Learning 2016
Cannabis and the Risk of Psychosis
© Cengage Learning 2016
• Serotonergic agonist
• No known medicinal value
• Hallucinogens
• Use results in tolerance, but not addiction
or withdrawal
• Flashbacks with extended use
LSD
© Cengage Learning 2016
• GABAA receptor agonist
• Stimulates dopaminergic reward pathways
• Rapid tolerance
• Damaging effects on health
Alcohol
© Cengage Learning 2016
Alcohol and Mortality
