Yoshiyuki Kubota

Distribution of substance P-like immunoreactivity in the lower brainstem of the human fetus: an immunohistochemical study.

The regional distribution of substance P-like immunoreactive (SPI) structures in the lower brainstem of the human fetus was investigated using the indirect immunofluorescence technique. SPI cells were found in a number of areas including the inferior colliculus, central gray matter of the midbrain, n. laterodorsalis tegmenti, midbrain and medullary reticular formation, n. vestibularis inferior, and n. prepositus hypoglossi. An extensive network of SPI fibers of varying densities were identified throughout the lower brainstem.

Immunohistochemical Evidence That Most Rat Corticotrophs Contain Beta-Adrenergic Receptors

Cells bearing beta-adrenergic receptors (beta-AdRs) were found in the anterior lobe of the rat pituitary gland using antiserum generated against affinity-purified beta 2-AdRs, which also cross-reacts with beta 1-AdRs. beta-AdR-positive cells were sparsely distributed in the anterior pituitary gland. The ultrastructure of these cells was similar to that of corticotrophs. Subsequent analysis of adjacent serial sections indicated that 75% of the ACTH-positive cells were beta-AdR-positive. Our findings demonstrate the presence of beta-AdRs on pituitary corticotrophs, which provides an anatomical basis for the direct regulation of corticotroph secretions by beta-adrenergic agents.

SPINY AND ASPINY TYPES OF NEUROPEPTIDE Y IMMUNOREACTIVE NEURONS IN THE MONKEY NEOSTRIATUM

The present study demonstrates the existence of two types of neurons with neuropeptide Y (NPY) immunoreactivity in the neostriatum of the monkey (Macacus fuscatus) by using the avidin-biotin-immunoperoxidase method. One type, accounted for about 80% of striatal NPY cells, corresponded to the medium-sized aspiny type neurons. The other type resembled the medium-sized, spiny type II neurons. These findings suggest that there are at least two functional subpopulations of NPY neurons in the monkey neostriatum.