Korean J Anat.  1999 Oct;32(5):749-760.

Quantitative Autoradiography on Ontogenic Development of alpha-Adrenoceptor in the Rat Cerebral Cortex

• Lee MK
• Lee SW
• Kook JH
• Chung YY
• Lee EJ
• Kim JK
• Bae CS

Abstract

Adrenoceptors mediate response to catecholamines throughout the body. To investigate postnatal ontogenic development of alpha1- and alpha2- adrenoceptors in the rat cerebral cortex, in vitro autoradiography was done on frontal, parietal and temporal cortex in P0, P5, P10, P15, P20, P30 and adult animals. Binding sites for the alpha1-adrenergic receptor ligand, [3H]-prazosin, and the alpha2-adrenergic receptor ligand, [3H]-rauwolscine, were visualized by in vitro autoradiography, and anatomically localized by comparing the autoradiogram to Nissl-stained sections. Nonspecific binding was detected with unlabeled phentolamine (alpha1) and yohimbine (alpha2). There is uniform increase in alpha1- and alpha2- adrenoceptors from birth through first three or four postnatal weeks, followed by a decrease to adult level. Two alpha-adrenoceptors have very different ontogenic patterns of distribution during postnatal development. alpha1- adrenoceptors were expressed differentially in different cortical (frontal, temporal, parietal) regions and in different cortical layers (layers V, II-IV, VI) at same age. alpha2- adrenoceptor was expressed homogenously in throughout regions and layers. These findings may provide evidence that alpha1- adrenoceptors are involved in regulating cortical development or function more specifically than alpha2- adrenoceptors during postnatal development.

Keyword

alpha- adrenergic receptor; Rat cerebral cortex; ontogeny; in vitro autoradiography; binding density

MeSH Terms

Adult
Animals
Autoradiography*
Binding Sites
Catecholamines
Cerebral Cortex*
Humans
Parturition
Phentolamine
Rabeprazole
Rats*
Receptors, Adrenergic
Yohimbine
Catecholamines
Phentolamine
Receptors, Adrenergic
Yohimbine