Neurotransmitters

2/18/2015 ANCY I MSc.

NEUROTRANSMITTERSBy Ancy Kurian

I MSc.(N)

2/18/2015 2ANCY KURIAN IMSc. Neurotransmitters

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


DEFINITION

• A chemical released from a nerve ending that

transmits impulses from one neuron (nerve

cell) to another neuron, or to a muscle cell


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


neuron

2/18/2015 ANCY KURIAN IMSc. Neurotransmitters 6

TYPICAL CHEMICAL SYNAPSE -

STRUCTURE



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


MECHANISM OF NEUROTRANSMITTER ACTION


Chemical Classification of Neurotransmitters:

Cholinergics - Acetylcholine

Biogenic Amines (modified amino acids) ,involved inslow synaptic transmission.

• Catecholamines: Dopamine, Norepinephrine (NE), andEpinephrine

• Indolamines

• Serotonin and Histamine (5-Hydroxytryptamine or 5-HT)

Amino Acids - involved in fast synaptic transmissionand are inhibitory and excitatory in action.

• GABA—Gamma ()-aminobutyric acid

• Glycine , Aspartate ,Glutamate2/18/2015 ANCY KURIAN IMSc. Neurotransmitters 11

Chemical Classification of Neurotransmitters: Neuropeptides

• formed by short chained peptides , slow acting synaptic transmitters.

• Egs are Substance P , Endorphins and Enkephalins , Somatostatin, gastrin, cholecystokinin, oxytocin, vasopressin, Leutinizing hormone releasing hormone (LHRH)

Purines

• Adenosine

• ATP

Gases and Lipids

• Nitric Oxide (NO)

• Carbonmonooxide (CO)

• Cannabinoids


Functional Classification

• Excitatory Neurotransmitter- eg; Glutamate,Aspartate,Adrenaline and Noradrenaline,Histamine,Nitric Oxide andAcetycholine

• Inhibitory Neurotransmitter–eg:GABA,Glycine,Adrenaline and Noradrenaline,Dopamine and Serotonin.


CAUSES

( Deficiency, Imbalance / Malfunctioning)


Food allergies & sensitivities

Chronic stressEnvironmental Toxins

GeneticsCandida

Overgrowth

Nutritional DeficienciesAlcohol, Drugs,

Nicotine

Diet

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.


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


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


NEUROTRANSMITTERS IN THE CENTRAL NERVOUS SYSTEM (contd…)

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 :


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 :


temporal lobe epilepsy,

spinal cerebellar

degeneration.



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



ALCOHOLISM & NEUROTRANSMITTERS


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


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.


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.



(1)DRUGS THAT INTERFER WITH

NEUROTRANSMITTERS (pdf)

(2)DRUGS THAT INCREASE /DECREASE/MIMIC

NEUROTRANSMITTERS (pdf)


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


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


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.


CONCLUSION


THANKYOU


Date post:	16-Jul-2015
Category:	Health & Medicine
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Neurotransmitters

Health & Medicine