Ontogeny of somatostatin receptors in the rat somatosensory cortex.
The distribution and density of SRIF receptors (SRIF-R) were studied during development in the rat somatosensory cortex by in vitro autoradiography with monoiodinated [Tyr0-DTrp8]S14. In 16-day-old fetuses (E16), intense labeling was evident in the intermediate zone of the cortex while low concentrations of SRIF-R were detected in the marginal and ventricular zones. The highest density of SRIF-R was measured in the intermediate zone at E18. At this stage, labeling was also intense in the internal part of the developing cortical plate; in contrast, the concentration of binding sites associated with the marginal and ventricular zones remained relatively low. Profound modifications in the distribution of SRIF-R appeared at birth. In particular, a transient reduction of receptor density occurred in the cortical plate. During the first postnatal week, the density of receptors measured in the intermediate zone decreased gradually; conversely, high levels of SRIF-R were observed in the developing cortical layers (II to VI). At postpartum day 13 (P13), a stage which just precedes completion of cell migration in the parietal cortex, the most intensely labeled regions were layers V-VI and future layers II-III. From P13 to adulthood, the concentrations of SRIF-R decreased in all cortical layers (I to VI) and the pattern of distribution of receptors at P21 was similar to that observed in the adults.(ABSTRACT TRUNCATED AT 250 WORDS)
Gonzalez
B J
BJ
Groupe de Recherche en Endocrinologie Moléculaire, CNRS URA 650, Unité Affiliée à l'INSERM, Mont-Saint-Aignan, France.
Leroux
P
P
Bodenant
C
C
Vaudry
H
H
D000375:Aging; D000818:Animals; D001345:Autoradiography; D005865:Gestational Age; D007457:Iodine Radioisotopes; D051381:Rats; D011919:Rats, Inbred Strains; D017981:Receptors, Neurotransmitter / Q000378:metabolism*; D017481:Receptors, Somatostatin; D013003:Somatosensory Cortex / Q000196:embryology / Q000254:growth & development* / Q000378:metabolism; D013004:Somatostatin / Q000378:metabolism*
D007457:Iodine Radioisotopes; D017981:Receptors, Neurotransmitter; D017481:Receptors, Somatostatin; D013004:Somatostatin