title: Development of tyrosine hydroxylase-immunoreactive systems in the brain of the larval lamprey Lampetra fluviatilis.
abstract: The development of the catecholaminergic system of the brain of the lamprey (Lampetra fluviatilis) was studied with immunocytochemistry in a series of larvae of different sizes by using two different antibodies directed against tyrosine hydroxylase (TH), the rate-limiting enzyme of catecholamine synthesis. In group 1 larvae (length: 29-54 mm, ages: 8 months to 1.5 years), the only TH-immunoreactive somata observed were located in the caudal wall of the recessus praeopticus (RP) and in the nucleus tuberculi posterioris (NTP). In group 2 larvae (length: 55-80 mm, ages: 1.5-2.5 years), the somata of immunolabeled cells of the NTP give rise to fibers, most of which are ascending and terminate in the corpus striatum. Additional immunoreactive cells are observed in the nucleus praeopticus (NP), which has differentiated, and in the spinal cord. In group 3 larvae (length: 81-110 mm, ages: 2.5-4 years), the spatial distribution of TH-immunoreactive elements (somata, fibers, and terminals) bears many resemblances to that seen in the adult. Immunolabeled cells may be observed in the olfactory bulb, in the nucleus commissurae postopticae (NCP), and in the nucleus dorsalis hypothalami (NDH). Nevertheless, some groups of TH-immunoreactive cells found in the adult are not observed in group 3 larvae; these may appear during the metamorphic phase. By comparative analysis, we show that, in spite of several differences, the spatiotemporal sequence of appearance of TH-immunoreactive cell bodies and fibers in the lamprey presents many similarities to that described in gnathostomes.
authors.affiliation: Institut National de la Santé et de la Recherche Médicale U-106, Hôpital de la Salpêtrière, 75013 Paris, France. jsimons@mnhn.fr
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Pierre-Simons
authors.forename: Jacques
authors.initials: J
authors.lastname: Repérant
authors.forename: Mohamed
authors.initials: M
authors.lastname: Mahouche
authors.forename: Roger
authors.initials: R
authors.lastname: Ward
mesh_terms: D000375:Aging / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000166:cytology / Q000201:enzymology / Q000254:growth & development*; D001931:Brain Mapping; D002395:Catecholamines / Q000096:biosynthesis*; D002454:Cell Differentiation / Q000502:physiology; D004027:Diencephalon / Q000166:cytology / Q000201:enzymology / Q000254:growth & development; D007150:Immunohistochemistry; D007798:Lampreys / Q000033:anatomy & histology / Q000254:growth & development* / Q000378:metabolism; D007814:Larva / Q000166:cytology / Q000201:enzymology / Q000254:growth & development*; D008636:Mesencephalon / Q000166:cytology / Q000201:enzymology / Q000254:growth & development; D009434:Neural Pathways / Q000166:cytology / Q000201:enzymology / Q000254:growth & development*; D009474:Neurons / Q000166:cytology / Q000201:enzymology*; D012249:Rhombencephalon / Q000166:cytology / Q000201:enzymology / Q000254:growth & development; D013116:Spinal Cord / Q000166:cytology / Q000201:enzymology / Q000254:growth & development; D013687:Telencephalon / Q000166:cytology / Q000201:enzymology / Q000254:growth & development; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism*
chemical_list: D002395:Catecholamines; D014446:Tyrosine 3-Monooxygenase