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Concepts of Neurobiology
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 “neuro scientific
revolution”, greater emphasis is placed on the
organic basis of mental illness
 Research is ongoing and new discoveries are
being made. fMRI and sMRI’s are giving us
new information.

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. Hindbrian or 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
bagel”or 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
Diencephalon Cont.
Basil Ganglia-Modulates motor behavior;
appropriate muscle tone and posture
 Balances excitatory (acetylcholine) and
inhibitory(dopamine) neurotransmitters in
extra-pyramidal system. GABA inhibits also.
 Hypothalmus, pituitary gland
 Thalmus: integrates sensory input,except
smell, which Limbic does

The Midbrain and Hindbrain
The midbrain, or mesencephalon, is
responsible for visual, auditory, and balance
(righting) reflexes. Substantia Nigra Produces
Dopamine in this area
 Hindbrain or Brain stem
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Pons: regulates respiration and muscle tone
Medulla: reg. heart rate, blood pressure,
Cerebellum: muscle tone and coordination
Nerve Tissue
 CNS:
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Cell body, contains nucleus
Axon, transmits message to next cell
Dendrites, receives messages from cells
 Three
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neurons, composed of:
classes of neurons in CNS
Afferent, (sensory)
Efferent, (motor)
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.
 Electrical impulses begins the process.
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
Neuroendocrinology
 Hypothalamus-has
direct control over
the pituitary gland, the “master gland”
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All these effect health. Our main concerns
are: TSH, ACTH, Melatonin
 Circadian
Rhythms- implications in
many mental illness as it effects the
ability to sleep.
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
dichotomy does not
exist. Each effects the other.
 A nurse never “Just takes care of the
body” even if you want to.
 Psychiatric/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
Psychiatric Nursing
 Learn
about mental illness
 Improve communication
 Psychotropic Medication
 Decrease your fear of “Mental Patients”
 Attend groups
Neurobiology
The End