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Concepts of Neurobiology
Copyright all rights reserved Austin Community College
Introduction
The 1990’s was called the “decade of the
Brain” with the challenge of studying the
biological basis of behavior
 In keeping with the “neurobiology scientific
revolution”, greater emphasis is placed on the
organic basis of mental illness
 Research is ongoing and new discoveries are
being made.

What makes a brain happy and
healthy?
Balanced Neurotransmitters
 Brain uses the most glucose

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Healthy Diet (serotonin/GABA shake)
Aerobic exercise
Empathic conversation
8 hours of sleep
Listening to music
Being in nature
Hearing an inspiring speech
Helping others
What makes a brain happy?
But is not so healthy
Coke, potato chips, and chocolate
 A margarita
 Going shopping
 Driving fast
 Cocaine
 Nicotine
 Rollercoasters/action movies
 Gambling
 Computer Games

Thee Parts of the Brain
 1.
Forebrain
– A. Cerebrum
– B. Diencephalon
 2.
Midbrain
 3. Brain Stem
 1.
The Forebrain
– A. Cerebrum
Consists
of right and left hemisphere connected
by a deep groove called the corpus callosum.
Each hemisphere is divided into four lobes:
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Frontal lobes
Parietal lobes
Temporal lobes
Occipital lobes
The Lobes of the Cerebrum:
a closer Look

Frontal lobes
– The executive;
decision maker,
reliant on other parts
of the brain for data.
Prefrontal is the
personality


Temporal Lobes
– Hearing
Parietal Lobes
– Perception,
interpertation touch
body perception

Occipital Lobes
– Sight
Forebrain: Diencephalon

The diencephalon
connects the cerebrum
with the lower brain
structures
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Limbic System: “the
“emotional brain:”
Limbic system consists of
many structures
Contain “4 F’s”-Feeding,
fighting, fleeing and
fornicating
Memory, Pleasure
Pathway, emotions,
motivation
Forebrain: Diencephalon
(Limbic System)
 Connects
the cerebrum with the lower
brain structures
 Very powerful
 Do not underestimate
 Pleasure Emotions Cravings Memories
 Can overwhelm the Frontal Lobe
Other Important Structures in the
Limbic System
 Hippocampus-Contains
memory
 Amigdala-stores affect about memories,
ie, fear, anger, rage, love, and happiness
 Both structures are bilateral, under the
temporal lobe
 VTA is a pathway in this
area of the brain that is the
seat of craving in addiction
Basil Ganglia
 controls
starting and stopping
movements
– Balances excitatory (acetylcholine) and
inhibitory(dopamine) neurotransmitters in
extra-pyramidal system (EPS). GABA
inhibits also.
– If there are changes in the balance between
acetylcholine and dopamine motor
function will abnormal.
Cerebellum
Second largest structure
 Dependent on the balance between
acetylcholine and dopamine for normal
movement
 Function (highly specialized)
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Movement
Posture
Balance
Sensory motor coordination
Hand eye coordination
The Midbrain and Brian Stem
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The midbrain contorls visual, auditory, and balance (righting) reflexes.
Substantia Nigra Produces Dopamine in this area
Brain stem
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Pons: regulates respiration and muscle tone
Medulla: reg. heart rate, blood pressure,
Cerebellum: muscle tone and coordination
Reticular Activating System

(not on test)
Responsible for
regulation of arousal
and sleep-wake
transitions.
Nerve Tissue
 Neurons
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Cell body, contains nucleus
Axon, transmits message to next cell
Dendrites, receives messages from cells
Myelin sheath: insulates and promotes conduction
 Three
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are composed of:
classes of neurons in CNS
Afferent: (sensory)
 Send messages to the brain
Efferent: (motor)
 Send messages away from the brain
Interneurons, in CNS
Neurons: a reveiw
Synapses
 The
synapse is the junction between
two neurons .
 Synaptic Cleft: space between neurons
 Pre-synaptic neuron: area of axon
where neurotransmitters are stored.
 Postsynaptic neuron: area of dendrite
where receptor sites are located.
Synapse: a review
Neurotransmitters
 Play
an important role in human
emotions and behavior
 Are the target for the mechanism of
action for psychotropic medications
 Summary: Neurotransmitters are
released into the synaptic cleft from the
axon to the dendrite. The substance is
either inactivated or returned to the
axon.
Categories of neurotransmitters
 Cholinergics
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Acetylcholine: involved in sleep, arousal,
movement, MEMORY,
 Monoamines
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Norepinephrine: effects mood, cognition,
perception, locomotion, CV functioning,
sleep and arousal
Monoamines:
 Dopamine:
effects movement,
coordination, emotions, voluntary
judgment, and release of prolactin
 Serotonin: effects sleep, arousal, libido,
appetite, mood, aggression, pain
perception, coordination, and judgment
 Histamine: Not sure of influence on
mood
Amino Acids and Neuropeptides
 Amino
Acid: gamma aminobutyric
acid(GABA) functions as an inhibitor
neurotransmitter. Has a calming effect.
 Neuropeptides: endorphins and
enkephlins, modulates pain and
reduces peristalsis. Also called “natural
opiates”
Autonomic Nervous System
 Sympathetic:
Dominates in stressful
situations, prepares body for fight or
flight
 Parasympathic: Dominates when
person is relaxed
Endocrine System:
a communication system
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Neurochemical Messengers called hormones:
Hypothalamus- instructs the pituitary gland
– The pituitary gland:

secretes TSH (Thyroid stimulation Hormone) stimulates target
cells in:
– The thyroid (energy level)
– The pituitary gland also stimulates target cells in the:
– The pituitary gland can monitors
The release ACTH (adrenal corticotropic
hormone) stimulates the adrenals
(response to stress cortisol)
 The gonads (testosterone and estrogen)

The Stress Response to Cortisol
Other factors in Neurobiology
 Genetics:
research has shown that all
major mental illness seem to have a
genetic base.
 Psychoimmunology: Normal immune
responses are decreased with grief,
bereavement, and depression.
Implications for Nursing
 Nature-Nurture:
Each effects the other.
 A nurse never “Just takes care of the
body” even if you want to.
 Mental health nurses can not “Just take
care of the mind.”
 “Pathophysiology” check lab work
daily. Listen and observe
Goals for the Student Nurse in
Mental Health Nursing
 Learn
about mental illness
 Improve communication
 Psychotropic Medication
 Decrease your fear of “Mental Patients”
 Attend groups
Neurobiology
The End