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)
Groupe de Recherche en Endocrinologie Moléculaire, CNRS URA 650, Unité Affiliée à l'INSERM, Mont-Saint-Aignan, France.
B J
BJ
Gonzalez
P
P
Leroux
C
C
Bodenant
H
H
Vaudry
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