Immunohistochemistry of Tryptophan Hydroxylase in the Rat Brain
Overview
Affiliations
An antiserum raised against tryptophan tetrahydropterine oxygen oxidoreductase was used to examine in rat brain the immunohistochemical localization of this rate-limiting enzyme catalysing the biosynthesis of serotonin. Tryptophan tetrahydropterine oxygen oxidoreductase was detected in numerous nerve cell bodies, proximal dendrites and axon varicosities or terminals corresponding to those of serotonin neurons as judged by their anatomical distribution and concomitant immunoreactivity to an antiserum against serotonin. In hypothalamus, a serotonin-containing nerve cell group previously visualized in the pars ventralis of the nucleus dorsomedialis by radioautography after serotonin uptake, and by serotonin immunohistochemistry after tryptamine loading, remained tryptophan tetrahydropterine oxygen oxidoreductase-unreactive even in rats treated with colchicine. On the other hand, a small group of tryptophan tetrahydropterine oxygen oxidoreductase-positive cells was identified in the rostrolateral portion of nucleus dorsomedialis, which could play a part in the intrinsic serotonin innervation of hypothalamus. There was no overlap between tryptophan tetrahydropterine oxygen oxidoreductase immunostaining and the cellular distribution of N-acetyl serotonin as reported in earlier studies. It is therefore likely that the synthesis of N-acetyl serotonin from tryptophan does not take place in N-acetyl serotonin-containing neurons.
Ahn K, Baker G, Jang W, Cha H, Moon M, Song M Invert Neurosci. 2018; 18(3):10.
PMID: 30128715 DOI: 10.1007/s10158-018-0214-6.
Ragan C, Harding K, Lonstein J Horm Behav. 2015; 77:62-71.
PMID: 26219576 PMC: 7005883. DOI: 10.1016/j.yhbeh.2015.07.017.
Nonexocytotic serotonin release tonically suppresses serotonergic neuron activity.
Mlinar B, Montalbano A, Baccini G, Tatini F, Berlinguer Palmini R, Corradetti R J Gen Physiol. 2015; 145(3):225-51.
PMID: 25712017 PMC: 4338157. DOI: 10.1085/jgp.201411330.
Adori C, Low P, Ando R, Gutknecht L, Pap D, Truszka F Psychopharmacology (Berl). 2010; 213(2-3):377-91.
PMID: 21052985 DOI: 10.1007/s00213-010-2041-2.
Decreased cortical serotonin in neonatal rabbits exposed to endotoxin in utero.
Kannan S, Saadani-Makki F, Balakrishnan B, Dai H, Chakraborty P, Janisse J J Cereb Blood Flow Metab. 2010; 31(2):738-49.
PMID: 20827261 PMC: 3049527. DOI: 10.1038/jcbfm.2010.156.