Distribution of neuropeptide Y immunoreactivity in the central and peripheral nervous systems of amphioxus (Branchiostoma lanceolatum Pallas).
Immunocytochemistry techniques were employed to investigate the distribution of neuropeptide Y-like-immunoreactive (NPY-ir) cells and fibers in the central and peripheral nervous systems of adult amphioxus. NPY-ir neurons of the commissural type were abundant in the brain and present but more scarce in the spinal cord. These neurons gave rise to conspicuous NPY-ir tracts that coursed along the entire length of the nerve cord. Some fibers exhibited conspicuous Herring body-like swellings. In the peripheral nervous system, small NPY-ir neurons and a large number of thin, beaded NPY-ir fibers were observed in the atrial region, indicating the involvement of this substance in visceral regulation. A few NPY-ir fibers, possibly afferent to the spinal cord, coursed in the ventral branches of the spinal nerves of this region, whereas no NPY-ir fibers coursed in the preoral or velar nerves or in the dorsal branches of the other spinal nerves. These results indicate that NPY is widely used as a neuroregulator/neurotransmitter in the central and peripheral nervous systems of this primitive chordate. In addition, this study demonstrates the presence of tall, thin NPY-ir cells in the putative adenohypophyseal homologue, the Hatschek's pit organ, which is located in the roof of the preoral cavity (vestibule).
Castro
Antonio
A
Department of Cell and Molecular Biology, Faculty of Sciences, University of A Coruña, 15071 A Coruña, Spain.
Manso
María Jesús
MJ
Anadón
Ramón
R
D000818:Animals; D001921:Brain / Q000378:metabolism*; D002816:Chordata, Nonvertebrate / Q000378:metabolism*; D007150:Immunohistochemistry; D009478:Neuropeptide Y / Q000378:metabolism*; D017933:Peripheral Nervous System / Q000378:metabolism*; D013116:Spinal Cord / Q000378:metabolism*; D014018:Tissue Distribution
D009478:Neuropeptide Y