Neurotransmitters
Neurotransmitters:
The cell should be able to synthesize the substance and be presented in the presynaptic terminal.
The substance should be released on depolarization of the terminal
There should be a specific receptor for it on the postsynaptic transmitters.
The substances can be subdivided into 3 major categories: 1-small molecules transmitters 2-peptides 3-
gaseous transmitters. Acetylcholine
Acetylcholine
Amino acids
Small-molecule neurotransmitters Biogenic amines ACh is the transmitter at NMJs The synthesis of acetylcholine:
Purines
Amino acids In the PNS (sympathetic and parasympathetic) Acetylcholine is synthesized in the
cholinergic presynaptic terminals from
Glutamate is the major excitatory CNS NT. In the CNS (brainstem nuclei, basal forebrain, acetylCoA+coline by choline
basal ganglia, and in the spinal cord). acetyltransferase.
Regulated after its release from the presynaptic terminal to
Cholinergic neurons (neurons that mainly use
allow normal synaptic transmission and prevent cell death
ACh as a main NT) diffuses throughout the
Membrane transporter proteins and absorption by Astro types.
neocortex , the hippocampus, and the amygdala; After synthesis, ACh is shipped
they are involved in memory functions. into vesicles to be released when
Glutamate transport cycle: Degeneration of these cells occurs in needed.
Alzheimer’s disesase, in which memory function
When glutamate is synthesized, in the presynaptic terminal, it’s The degradation of acetylcholine:
is lost
shipped into vesicles.
After release, the ACh is terminated by
acetylcholinesterase in the synaptic cleft
The vesicles fuse to the membrane and release the NT.
Biogenic Amines Hydroyzes ACh into acetate and choline, the
choline is taken back to the presynaptic
The glutamate bind to specific receptors in the postsynaptic, and Dopamine, norepinephrine, and epinephrine are catecholamines
membrane.
opens the channels. and derived from tyrosine.
The conversion of tyrosine : tyrosine is converted to I- dopa by tyrosine
hyroxylase. Then converted to dopamine by dopa- decarboxylase.
When channels close, glutamate is taken up by the Glial cell and
converted to glutamine by glutamine synthase.
Dopamine B- hydroxylase converts dopamine to norepinephrine
Glutamine goes to the presynaptic neuron and then converted back Add a methyl group via phenylthanolamine-N- methyl transferase to form epinephrine.
to glutamate by glutaminase.
The conversion of tryptophan: tryptophan is converted to 5-hydroxytryptophan by tryptophan 5-
hydroxylase, then converted to serotonin.
When glutamate binds to the postsynaptic channel and cause Conversion of histidine to histamine: by histidine decarboxylase.
it to open:
3 Na+ in 1 K+ out. The removal of synaptically released Biogenic amines, by the reuptake into astrocytes and neurons
GABA is the major inhibitory NT in the nervous system. Catecholamines are degraded by 2 enzymes Monoamine oxidase.
Catechol O-methyltransferase.
Produced from glutamate by enzyme that is only pressent in neurons Neurons that generate Biogenic amines as NT are found within one of a few brainstem
that use GABA.
It’s possible to identify as inhibitory GABAergic neurons by using Noradrenergic neurons are found in the locus coeruleus and nucleus subcoeruleus of the dorsal
antibodies to the enzyme. part of the rostral pons.
Medium spiny neurons of the striatum and the punkinjie cells
Norepinephrine is also important in the PNS, because it’s used by postganglionic sympathetic
contain GABAergic.
4 GABA transporter ( GAT1, GAT2, GAT3, and BGT1) genes. GATQ, and Serotoninergic fibers arise from a series of nuclei in the midline of the brainstem “raphe nuclei”.
GAT3 in CNS. They are distributed throughout the brain and spinal cord.
Depending on region and species, they can be expressed in neurons and glia. Dopaminergic fibers arise from substantia Nigra pars compacta and the ventral tegmental area.
Glycine is an inhibitory NT. Histaminergic neurons are located within the tuberomammillary nucleus of the hypothalamus
Adrenergic neurons are few and located in the rostral medulla.
Glycinergic synapses found in the spinal cord (half of the inhibitory
synapses) , lower brainstem, cerebellum, and retina.
At excitatory NMDA-type glutamate receptors, glycine must be Purines
found for opening ion channel.
ATP can act as a transmitter or co-transmitter at synapses in the PNS&CNS.
2 glycine transporters (GlyT1,GlyT2). GlyT1 found on astrocytes and
in the CNS. ATP has its own receptors. They are coupled ion channels.
GlyT2 is located on glycinergic nerve terminals in the spinal cord,
brainstem, and cerebellum. Glial cells can release ATP at certain stimulation.
Neurotransmitters:
The cell should be able to synthesize the substance and be presented in the presynaptic terminal.
The substance should be released on depolarization of the terminal
There should be a specific receptor for it on the postsynaptic transmitters.
The substances can be subdivided into 3 major categories: 1-small molecules transmitters 2-peptides 3-
gaseous transmitters. Acetylcholine
Acetylcholine
Amino acids
Small-molecule neurotransmitters Biogenic amines ACh is the transmitter at NMJs The synthesis of acetylcholine:
Purines
Amino acids In the PNS (sympathetic and parasympathetic) Acetylcholine is synthesized in the
cholinergic presynaptic terminals from
Glutamate is the major excitatory CNS NT. In the CNS (brainstem nuclei, basal forebrain, acetylCoA+coline by choline
basal ganglia, and in the spinal cord). acetyltransferase.
Regulated after its release from the presynaptic terminal to
Cholinergic neurons (neurons that mainly use
allow normal synaptic transmission and prevent cell death
ACh as a main NT) diffuses throughout the
Membrane transporter proteins and absorption by Astro types.
neocortex , the hippocampus, and the amygdala; After synthesis, ACh is shipped
they are involved in memory functions. into vesicles to be released when
Glutamate transport cycle: Degeneration of these cells occurs in needed.
Alzheimer’s disesase, in which memory function
When glutamate is synthesized, in the presynaptic terminal, it’s The degradation of acetylcholine:
is lost
shipped into vesicles.
After release, the ACh is terminated by
acetylcholinesterase in the synaptic cleft
The vesicles fuse to the membrane and release the NT.
Biogenic Amines Hydroyzes ACh into acetate and choline, the
choline is taken back to the presynaptic
The glutamate bind to specific receptors in the postsynaptic, and Dopamine, norepinephrine, and epinephrine are catecholamines
membrane.
opens the channels. and derived from tyrosine.
The conversion of tyrosine : tyrosine is converted to I- dopa by tyrosine
hyroxylase. Then converted to dopamine by dopa- decarboxylase.
When channels close, glutamate is taken up by the Glial cell and
converted to glutamine by glutamine synthase.
Dopamine B- hydroxylase converts dopamine to norepinephrine
Glutamine goes to the presynaptic neuron and then converted back Add a methyl group via phenylthanolamine-N- methyl transferase to form epinephrine.
to glutamate by glutaminase.
The conversion of tryptophan: tryptophan is converted to 5-hydroxytryptophan by tryptophan 5-
hydroxylase, then converted to serotonin.
When glutamate binds to the postsynaptic channel and cause Conversion of histidine to histamine: by histidine decarboxylase.
it to open:
3 Na+ in 1 K+ out. The removal of synaptically released Biogenic amines, by the reuptake into astrocytes and neurons
GABA is the major inhibitory NT in the nervous system. Catecholamines are degraded by 2 enzymes Monoamine oxidase.
Catechol O-methyltransferase.
Produced from glutamate by enzyme that is only pressent in neurons Neurons that generate Biogenic amines as NT are found within one of a few brainstem
that use GABA.
It’s possible to identify as inhibitory GABAergic neurons by using Noradrenergic neurons are found in the locus coeruleus and nucleus subcoeruleus of the dorsal
antibodies to the enzyme. part of the rostral pons.
Medium spiny neurons of the striatum and the punkinjie cells
Norepinephrine is also important in the PNS, because it’s used by postganglionic sympathetic
contain GABAergic.
4 GABA transporter ( GAT1, GAT2, GAT3, and BGT1) genes. GATQ, and Serotoninergic fibers arise from a series of nuclei in the midline of the brainstem “raphe nuclei”.
GAT3 in CNS. They are distributed throughout the brain and spinal cord.
Depending on region and species, they can be expressed in neurons and glia. Dopaminergic fibers arise from substantia Nigra pars compacta and the ventral tegmental area.
Glycine is an inhibitory NT. Histaminergic neurons are located within the tuberomammillary nucleus of the hypothalamus
Adrenergic neurons are few and located in the rostral medulla.
Glycinergic synapses found in the spinal cord (half of the inhibitory
synapses) , lower brainstem, cerebellum, and retina.
At excitatory NMDA-type glutamate receptors, glycine must be Purines
found for opening ion channel.
ATP can act as a transmitter or co-transmitter at synapses in the PNS&CNS.
2 glycine transporters (GlyT1,GlyT2). GlyT1 found on astrocytes and
in the CNS. ATP has its own receptors. They are coupled ion channels.
GlyT2 is located on glycinergic nerve terminals in the spinal cord,
brainstem, and cerebellum. Glial cells can release ATP at certain stimulation.
