TY - JOUR
T1 - Two-step production of monoamines in monoenzymatic cells in the spinal cord
T2 - A different control strategy of neurotransmitter supply?
AU - Zhang, Mengliang
PY - 2016/12/1
Y1 - 2016/12/1
N2 - Monoamine neurotransmitters play an important role in the modulation of sensory, motor and autonomic functions in the spinal cord. Although traditionally it is believed that in mammalian spinal cord, monoamine neurotransmitters mainly originate from the brain, accumulating evidence indicates that especially when the spinal cord is injured, they can also be produced in the spinal cord. In this review, I will present evidence for a possible pathway for two-step synthesis of dopamine and serotonin in the spinal cord. Published data from different sources and unpublished data from my own ongoing projects indicate that monoenzymatic cells expressing aromatic L-amino acid decarboxylase (AADC), tyrosine hydroxylase (TH) or tryptophan hydroxylase (TPH) are present in the spinal cord and that these TH and THP cells often lie in close proximity to AADC cells. Prompted by the above evidence, I hypothesize that dopamine and serotonin could be synthesized sequentially in two monoenzymatic cells in the spinal cord via a TH-AADC and a TPH-AADC cascade respectively. The monoamines synthesized through this pathway may compensate for lost neurotransmitters following spinal cord injury and also may play specific roles in the recovery of sensory, motor and autonomic functions.
AB - Monoamine neurotransmitters play an important role in the modulation of sensory, motor and autonomic functions in the spinal cord. Although traditionally it is believed that in mammalian spinal cord, monoamine neurotransmitters mainly originate from the brain, accumulating evidence indicates that especially when the spinal cord is injured, they can also be produced in the spinal cord. In this review, I will present evidence for a possible pathway for two-step synthesis of dopamine and serotonin in the spinal cord. Published data from different sources and unpublished data from my own ongoing projects indicate that monoenzymatic cells expressing aromatic L-amino acid decarboxylase (AADC), tyrosine hydroxylase (TH) or tryptophan hydroxylase (TPH) are present in the spinal cord and that these TH and THP cells often lie in close proximity to AADC cells. Prompted by the above evidence, I hypothesize that dopamine and serotonin could be synthesized sequentially in two monoenzymatic cells in the spinal cord via a TH-AADC and a TPH-AADC cascade respectively. The monoamines synthesized through this pathway may compensate for lost neurotransmitters following spinal cord injury and also may play specific roles in the recovery of sensory, motor and autonomic functions.
KW - 5-hydroxytryptophan
KW - Aromatic L-amino acid decarboxylase
KW - Dopamine
KW - L-dopa
KW - Monoamine precursor
KW - Non-monoaminergic cell
KW - Serotonin
KW - Spinal cord injury
KW - Tryptophan hydroxylase
KW - Tyrosine hydroxylase
U2 - 10.4103/1673-5374.197124
DO - 10.4103/1673-5374.197124
M3 - Journal article
AN - SCOPUS:85009204478
VL - 11
SP - 1904
EP - 1909
JO - Neural Regeneration Research
JF - Neural Regeneration Research
SN - 1673-5374
IS - 12
M1 - 10.4103/1673-5374.197124
ER -