Neurotransmitters and
Neuromodulators
Criteria for neurotransmitters
synthesis - in the presynaptic neurons
localization - in the presynaptic terminal
release - should be released into the synapse when there is
stimulation (action potential)
response mimicry - if we inject the chemical, will we get
the same response? if the same response is given when
experimentally applies, the response will be similar to the
biological response.
inactivation - a specific mechanism is there to remove the
molecule from the synpatic cleft or to degrade it. could be
reuptake, diffusion or break down by an enzyme. eg.
acetylcholinesterase, COMT, MAO
Neurotransmitters vs neuromodulators
neuromodulators are chemicals that are not transmitters but
they can modify how the transmitters are gonna perform
their function
eg. testosterone. with an increase in testosterone there
is an increase in aggressive behaviour
Neurotransmitters classification
Amines
eg. dopamine, E, NE, serotonin, histamine
they act fast (rapid acting)
stored in small dense vesicles
acts on ion channels
Neurotransmitters and Neuromodulators 1
, there is reuptake and recycling of the vesicle
Amino acids
excitatory amino acids - glutamate and aspartate. causes
depolarization
inhibitory amino acids - glycine and GABA. causes
hyperpolarization
they are rapidly acting
stored in small clear vesicles
acts on ion channels
there is reuptake and recycling of vesicle
Neuropeptides
eg. substance P, vasopressin, endorphins, neurotensins
purines and pyrimidine - adenosine, ATP
slowly acting
stored in large dense vesicles
acts through secondary messenger system (G protein)
synthesized by ribosomes in the neuronal cell body
Gases: NO, CO
NO in the postsynaptic neuron, changes intracellular
metabolic functions that modify neuronal excitability
possible role in memory and learning
Lipids (anandamide)
prostaglandins
neurosteroids
Neurotransmitters and Neuromodulators 2
Neuromodulators
Criteria for neurotransmitters
synthesis - in the presynaptic neurons
localization - in the presynaptic terminal
release - should be released into the synapse when there is
stimulation (action potential)
response mimicry - if we inject the chemical, will we get
the same response? if the same response is given when
experimentally applies, the response will be similar to the
biological response.
inactivation - a specific mechanism is there to remove the
molecule from the synpatic cleft or to degrade it. could be
reuptake, diffusion or break down by an enzyme. eg.
acetylcholinesterase, COMT, MAO
Neurotransmitters vs neuromodulators
neuromodulators are chemicals that are not transmitters but
they can modify how the transmitters are gonna perform
their function
eg. testosterone. with an increase in testosterone there
is an increase in aggressive behaviour
Neurotransmitters classification
Amines
eg. dopamine, E, NE, serotonin, histamine
they act fast (rapid acting)
stored in small dense vesicles
acts on ion channels
Neurotransmitters and Neuromodulators 1
, there is reuptake and recycling of the vesicle
Amino acids
excitatory amino acids - glutamate and aspartate. causes
depolarization
inhibitory amino acids - glycine and GABA. causes
hyperpolarization
they are rapidly acting
stored in small clear vesicles
acts on ion channels
there is reuptake and recycling of vesicle
Neuropeptides
eg. substance P, vasopressin, endorphins, neurotensins
purines and pyrimidine - adenosine, ATP
slowly acting
stored in large dense vesicles
acts through secondary messenger system (G protein)
synthesized by ribosomes in the neuronal cell body
Gases: NO, CO
NO in the postsynaptic neuron, changes intracellular
metabolic functions that modify neuronal excitability
possible role in memory and learning
Lipids (anandamide)
prostaglandins
neurosteroids
Neurotransmitters and Neuromodulators 2
