Coexistence of tyrosine hydroxylase and serotonin in the raphe nucleus of the laboratory shrew (Suncus murinus) during postnatal life.
Immunoreactivity (IR) of tyrosine hydoroxylase (TH), which is the rate-limiting enzyme of catecholamine (CA) synthesis, was observed in the serotonergic neurons of the raphe nucleus (RN) of the newborn laboratory shrew from postnatal day (P) 0 to P14. Using an immunohistochemical method involving highly specific antibodies produced in our laboratory, we found that these RN neurons were TH-, GTP cyclohydrolase I-, aromatic L-amino acid decarboxylase-immunoreactive, but DOPA- and dopamine-immunonegative. In addition, they were tryptophan-, 5-hydroxytryptophan- and serotonin-immunoreactive. These results suggest that TH in serotonergic neurons of RN of laboratory shrew has no function as a CA-synthesizing enzyme but may play some role as a regulator or a subsidiary factor in the postnatal development of serotonergic neurons.
Karasawa
N
N
Department of Anatomy, School of Medicine, Fujita Health University, Aichi, Japan.
Arai
R
R
Isomura
G
G
Nagatsu
T
T
Nagatsu
I
I
D000818:Animals; D000831:Animals, Newborn; D000918:Antibody Specificity; D001142:Aromatic-L-Amino-Acid Decarboxylases / Q000032:analysis; D005260:Female; D006136:GTP Cyclohydrolase / Q000032:analysis; D007150:Immunohistochemistry; D008297:Male; D011903:Raphe Nuclei / Q000737:chemistry* / Q000201:enzymology / Q000254:growth & development; D012701:Serotonin / Q000032:analysis*; D012788:Shrews; D014364:Tryptophan / Q000032:analysis; D014446:Tyrosine 3-Monooxygenase / Q000032:analysis*
D012701:Serotonin; D014364:Tryptophan; D014446:Tyrosine 3-Monooxygenase; D006136:GTP Cyclohydrolase; D001142:Aromatic-L-Amino-Acid Decarboxylases