Co-localization of mu opioid receptor is greater with dynorphin than enkephalin in rat striatum.
Using a combination of radioactive and non-radioactive in situ hybridization, the mu opioid receptor mRNA was localized in enkephalin as well as dynorphin neurones of the rat striatum. The proportion of enkephalin neurones showing co-localized mu opioid receptor mRNA was dependent on the rostrocaudal level (17-39% in rostral/intermediate levels vs 0.4-5% caudally) but did not differ between striatal subregions. For dynorphin neurones the reverse was true, with consistently higher levels of co-localization in the caudate-putamen (56-77%) than the nucleus accumbens (15-43%), but no differences along the rostrocaudal axis. Furthermore, the degree of enkephalin/mu co-localization was significantly lower than that of dynorphin/mu. These results suggest a fine-grained topological differentiation of mu receptor modulation of striatal opioid systems.
Guttenberg
N D
ND
Vrije Universiteit, Department of Anatomy and Embryology, Amsterdam, The Netherlands.
Klop
H
H
Minami
M
M
Satoh
M
M
Voorn
P
P
D000818:Animals; D002421:Caudate Nucleus / Q000166:cytology / Q000378:metabolism; D003342:Corpus Striatum / Q000166:cytology / Q000378:metabolism*; D004399:Dynorphins / Q000032:analysis / Q000096:biosynthesis*; D004745:Enkephalins / Q000032:analysis / Q000096:biosynthesis*; D008297:Male; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D011699:Putamen / Q000166:cytology / Q000378:metabolism; D015347:RNA Probes; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D051381:Rats; D017208:Rats, Wistar; D017450:Receptors, Opioid, mu / Q000032:analysis / Q000096:biosynthesis*
D004745:Enkephalins; D015347:RNA Probes; D012333:RNA, Messenger; D017450:Receptors, Opioid, mu; D004399:Dynorphins