3. OVERVIEW
• Definition & Life-cycle of a neurotransmitter
• Mechanism of Neurotransmitter Action
• Classification Of Neurotransmitters
• Factors influencing - Deficiency/ imbalance/ Malfunctioning
• Neurotransmitters and probable Implications on Mental
Health
• Diagnosis Of Neurotransmitter imbalance
• PSYCHOPHARMACOLOGY
How does drugs alter Neurotransmission
Mechanism of Action Of Drugs
Drugs interfering with Neurotransmission
Drugs that increase/ decrease /mimic Neurotransmitters.
• NURSES CONCERN IN NEUROTRANSMITTER
IMBALANCE
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4. DEFINITION
• A chemical released from a nerve ending that
transmits impulses from one neuron (nerve
cell) to another neuron, or to a muscle cell
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5. Neurotransmitters (contd…)
• Act as both neurotransmitters and hormones
• Most neurons make two or more neurotransmitters
• 50 or more neurotransmitters have been identified.
• 9 low molecular weight amines that serves as neurotransmitters
egs.Glutamate ,the major fast excitatory transmitter in
mammalian CNS ,
Acetycholine- the excitatory transmitter at the vertebral
junction,
GABA and Glycine ,the major fast inhibitory transmitters in
brain & spinal cord.
• Central nervous system, the peripheral nervous system has only
two: acetylcholine and norepinephrine
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9. Life Cycle of a Neurotransmitter
1) Synthesis of the transmitter
2) Packaging and storage in Synaptic
vesicles
3) If necessary, transport from the site of
synthesis to the site of release from
the nerve terminal
4) Release in response to an action potential
5) Binding to postsynaptic receptor proteins
6) Termination of action by
diffusion,destruction, or reuptake
into cells
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15. Neurotransmitter levels and Emotional Health
• Emotional health - combination of attitudes,
personality, support systems, and our brain’s
neurotransmitter levels
• Recognizing changes - important part of
treatment and returning to normal and reducing
our stress.
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16. NEUROTRANSMITTERS IN THE CENTRAL NERVOUS SYSTEM
Neurotransmitter Location
Possible
Implications for
Mental illness
I. Cholinergics
A. Acetycholine ANS-Sympathetic and parasympathetic
presynaptic nerve terminals; parasympathetic
post-synaptic nerve terminals.
CNS- Cerebral cortex ,hippocampus ,limbic
structures, and basal ganglia.
Functions : Sleep,
arousal,pain,perception,movement,memory
Increased levels:
Depression
Decreased levels :
Alzheimer’s Disease,
Huntington’s disease,
Parkinson’s
Disease
I. Monoamines
A. Norepinephrine ANS - Sympathetic post-synaptic nerve
terminals.
CNS – Thalamus, hypothalamus ,limbic system
,hippocampus, cerebellum ,cerebral cortex.
Functions: Mood, cognition ,perception
,locomotion ,cardiovascular functioning and
sleep and arousal.
Decreased levels :
Depression
Increased levels :
Mania, Anxiety states,
Schizophrenia
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17. A. Dopamine Frontal cortex, limbic system ,basal
ganglia, thalamus ,posterior pituitary and
spinal cord.
Functions : Movement and coordination,
emotions ,voluntary judgment ,release of
prolactin.
Decreased Levels :
Parkinson’s disease
and Depression
Increased levels :
Mania and
Schizophrenia
A. Serotonin Hypothalamus ,thalamus, limbic system,
cerebral cortex, cerebellum, spinal cord
Function : Sleep and arousal, libido,
appetite, mood ,aggression ,pain,
perception, coordination, judgement.
Increased levels :
Anxiety states
Decreased levels :
Depression
A. Histamine Hypothalamus
Functions : Wakefulness,pain,sensation
and inflammatory response
Decreased levels -
Depression
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NEUROTRANSMITTERS IN THE CENTRAL NERVOUS SYSTEM (contd…)
18. I. Amino Acids
A. Gamma-amino-butyric
acid(GABA)
Hypothalamus, hippocampus, cortex,
cerebellum ,basal ganglia, spinal cord,
retina
Functions: Slowdown of body activity
Decreased levels :
Huntington’s disease,
anxiety disorders,
schizophrenia, and
various forms of epilepsy
A. Glycine Spinal cord and brain stem
Functions : Recurrent inhibition of motor
neurons
Toxic levels :”glycine
encephalopathy”,
decreased levels are
correlated with spastic
motor movements.
C. Glutamate and Asparate Pyramidal cells of the cortex, cerebellum
and the primary sensory afferent systems
,hippocampus. thalamus, hypothalamus,
spinal cord
Functions: Relay of sensory information
and in the regulation of various motor and
spinal reflexes
Increased levels :
Huntington’s disease,
temporal lobe epilepsy,
spinal cerebellar
degeneration.
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NEUROTRANSMITTERS IN THE CENTRAL NERVOUS SYSTEM (contd…)
19. I. NEUROPEPTIDES
A. Endorphins
and
Enkephalins
Hypothalamus, thalamus ,limbic structures ,mid brain and
brain stem;
Enkephalins are also found in the gastro- intestinal tract
Functions : Modulation of pain and reduced peristalsis
(enkephalins)
Modulation of dopamine
activity by opoid
neuropeptides may
indicate some link to the
symptoms of
schizophrenia
A. Substance P Hypothalamus, thalamus ,midbrain, brain stem, limbic
structures ,basal ganglia and spinal cord ,also found in
gastro-intestinal tract and salivary glands.
Function: Regulation of pain.
Increased levels :
Depression
Decreased levels :
Huntington’s disease and
Alzheimer’s disease
A. Somatostatin Cerebral cortex, hippocampus ,thalamus ,basal ganglia,
brain stem and spinal cord
Function stimulates release of dopamine ,serotonin
,norepinephrine and acetylcholine, and inhibits release of
norepinephrine, histamine and glutamate .
Also acts as a neuromodulator for serotonin in the
hypothalamus
Increased levels :
Huntington’s disease
Decreased levels :
Alzheimer's disease
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NEUROTRANSMITTERS IN THE CENTRAL NERVOUS SYSTEM (contd…)
21. DIAGNOSIS OF NEUROTRANSMITTER IMBALANCE
• Identify the causes
• Identify the symptoms
Symptoms of Neurotransmitter Imbalances or Neurotransmitter
Deficiency
• Diagnostic tests
Neurotransmitter Testing and Screening using urine samples
Urine test that measures the actual levels of neurotransmitters in
the urine.
Brain Scans
Live Studies
Brain Tissue Assays
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22. DRUGS ALTER NEUROTRANSMISSION
• Agonist: A drug that facilitates the effects of a particular
neurotransmitter on the postsynaptic cell.
• Ways that drugs can agonize
• block auto-receptors
• inhibition of reuptake
• inhibition of deactivation
• precursor to neurotransmitter
• stimulate release
• receptor binding etc.
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23. DRUGS ALTER NEUROTRANSMISSION
• Antagonist: A drug that opposes or inhibits the effects
of a particular neurotransmitter on the postsynaptic
cell.
• Ways that drugs can antagonize
• prevent synthesis
• prevents storage
• block release
• receptor blocker
• stimulates autoreceptors
• Binds at same site neurotransmitter would.
• Binds at different site.
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25. (1)DRUGS THAT INTERFER WITH
NEUROTRANSMITTERS (pdf)
(2)DRUGS THAT INCREASE /DECREASE/MIMIC
NEUROTRANSMITTERS (pdf)
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26. NURSES’ CONCERN IN NEUROTRANSMITTER
IMBALANCE
• Assessment
• Identify the markers showing adverse effects due to prolonged
use of medications
• Replenishing neurotransmitters
Diet
Aminoacid therapy
Health education
Rehabilitation
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27. NURSING DIAGNOSIS
• Risk for injury related to accelerated motor activity
• Disturbed thought process related to impaired judgement associated with manic
behaviour
• Self-care deficit (unkempt appearance) related to hyperactivity
• Impaired verbal communication –flight of ideas related to accelerated thinking
• Ineffective coping related to elated expressive mood
• Disturbed thought process –grandiosity related to elevated mood
• Ineffective coping related to emotional liability associated with manic behaviour
• Disturbed thought process –related to delusion of grandeur
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28. RESEARCH STUDIES
• A 1999 study at Duke University and published in the
Archives of Internal Medicine found that regular
exercise was effective in decreasing symptoms of major
depressive disorder..
• "Journal of Psychiatry & Neuroscience," - exercise also
increases serotonin levels in your brain, leading to
improved mood
• And " exposure to the great outdoors, even on a cloudy
day, can provide enough natural light to raise your
serotonin levels.
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