Neurotransmitters Flashcards
Neurotransmitter Molecules
Small molecule neurotransmitters
Larger neuropeptide neurotransmitters
Small molecule Neurotransmitters
Acetylcholine
Excitatory
Small molecule Neurotransmitters
Type Amino acids with inhibitory effect
Gamma amino butyric acid GABA
Glycine
Small molecule Neurotransmitters
Type Amino acids with excitatory effect
Glutamate
Aspartate
Small molecule Neurotransmitters
Biogenic amines -all have excitatory effect
Dopamine
Noradrenaline
Serotonin
Histamine
Neuropeptide Neurotransmitters
CCBSNSBVA
Corticotropin releasing hormone corticotropin (ACTH) Beta-endorphin Substance P Neurotensin Somatostatin Bradykinin Vasopressin Angiotensin II
Serotonin
Small molecule
Biogenic amine- excitatory
<2% in CNS
Synthesised from tryptophan (amino acid)
located in nerve pathways in brain–
raphe nuclei (nuclei group in center of
reticular formation in the midbrain, pons,&
medulla.
Spreads extensively throughout the
brainstem, cerebral cortex, & spinal cord
Serotonin
Controls Mood Other functions effected by serotonin sleep regulation, pain perception, body temperature, blood pressure, & hormone activity
Serotonin
Outside the brain
GI
Cardiovascular system
Noradrenaline
monoamine neurotransmitter
located in the locus coerulus, pons, & reticular formation in brain
links to cortex, hippocampus, thalamus, & midbrain
excites activity in the brain
noradrenergic pathways control attention and arousal
Noradrenaline
Outside the brain
Sympathetic Nervous system
causes changes in BP, HR, GI FX
Explains broad effect of meds which affect monoamine neurotransmitters (tricyclics)
Dopamine
monoamine neurotransmitter
located in basal ganglia (very specific group of neurons)
widely distributed throughout the brain by 3 dopamine pathways
Dopamine pathways
Nigrostriatal
mesocorticolimbic
tuberohypophyseal
Dopamine concentration in brain
decreased = Parkinson's Disease increased = Schizophrenia
Acetylcholine
cholinergic pathways concentrated in the brainstem
effects cognitive functions esp memory
damage to pathways-probable cause of Alzheimer’s
Acetylcholine
Outside the brain
Main neurotransmitter in Parasympathetic Nervous system
which controls HR, digestion, saliva
secretion, bladder fx
Meds which affect cholinergic activity affect fx–ie, dry mouth
Neurotransmitter receptors
locate on the neuronal post synaptic membrane
Neurotransmitter receptors
types
ligand-gated receptors
G protein linked receptors
Ligand -gated receptors
or
ionotropic receptors
or fast receptors
excitatory neurotransmitters -EPSP
inhibitory neurotransmitters-IPSP
opens channel for influx of chloride and potassium ions into cell
Ligand-gated receptors
EPSP
IPSP
Excitatory post synaptic potential
Inhibitory post synaptic potential
G protein linked receptors
linked to ion channels indirectly by second message system
G-proteins & adenylate
G protein linked receptors
Gi protein
Gs protein
Gi-inhibitory effect
Gs= excitatory effect
G protein receptors
or slow receptors
or metabotropic
GABA-B
glutamate
Dopamine (D1 & D2)
5-HT1A, 5-HT1B, 5-HT1D, 5-HT2A, & %-HT2C receptors
Serotonin receptor
5 HT1
Distribution- brain intestinal nerves
Roles- Neuronal inhibition, behavioral effects,
cerebral constriction
Serotonin receptor
5-HT2
Distributed- brain, heart, lungs, smooth
muscleGI, blood vessels, platlets
Roles-Neuronal excitation, vasoconstriction, behavioral effects, depression, anxiety
Serotonin receptor
5-HT3
Distributed - limbic system, peripheral nueral system
Roles-nausea, anxiety
Serotinin Receptor
5HT4
Distribution CSN, Smooth muscle
Role -Neuronal excitation GI
Serotonin
5 HT5
5HT6
5ht&
Distribution- Brain
Role -UNKNOWN
Noradrenaline receptor
Alpha1
Brain, smooth muscle
vasoconstriction, smooth muscle control
Noradrenaline receptor
Alpha2
Brain, pancreas, smooth muscle
vasoconstriction, presynaptic effect in GI (relaxant)
Noradrenaline receptor
Beta1
heart, brain
heart rate increase
Noradrenaline receptor
Beta2
lungs, brain, skeletal muscle
Bronchial relaxant, vasodilation
Noradrenaline receptor
Beta3
post synaptic effector cells
stimulation of effector cells
Dopamine receptor
D1, D5 like
brain smooth muscle
Stimulatory, role in Schizophrenia ?
Dopamine receptor
D2,3,4 like
brain, cardiovascular system, presynaptic nerve terminals
Inhibitory, role in Schizophrenia?
Acetylcholine receptor
M1
Nerves
CNS excitation, gastric acid secretion
Acetylcholine receptor
M2
Heart, nerves, smooth muscle
Cardiac inhibition
neural inhibition
Acetylcholine receptor
M3
glands, smooth muscle, endothelium
Smooth muscle contraction, vasodilation
Acetylcholine receptor
M4
?CNS?
UNKNOWN
Acetylcholine receptor
M5
?CNS?
UNKNOWN
Acetylcholine receptor
NM
Skeletal muscles, neuromuscular junction
Neuromuscular transmission
Acetylcholine receptor
NN
postganglionic cell body dendrites
Ganglionic transmission
CO transmission
Neuropeptides can be neurotransmitters or co transmitters
overlapping effects of neurotransmitters
noradrenaline, serotonin, dopamine
monoamine reuptake and breakdown
reuptake clears the neurotransmitter from the synapse.
they are broken down by monoamine oxidase in the synapse.
