The rat nucleus accumbens: two levels of complexity in the distribution of glutamic acid decarboxylase (67 kDa) and preproenkephalin messenger RNA.
The distribution of messenger RNAs (mRNAs) encoding the 67 kDa isoform of glutamic acid decarboxylase (GAD67), a rate-limiting enzyme in the biosynthesis of gamma-aminobutyric acid, and preproenkephalin (PPE), the precursor of enkephalin, was analysed in the rat nucleus accumbens (NAS) taking in account its compartmentation in 'core' (NAS(core)) and 'shell' (NASshell). While GAD67 mRNA levels were more abundant (+48%) in NASshell than in NAS(core), hybridization signals for PPE mRNA were mainly found in NAScore. At a cellular level, hybridization signals for GAD67 mRNA were present in 75% and 80% of neurons NASshell and NAS(core), respectively. The level of GAD67 mRNA found higher in the NASshell corresponds in fact to a greater density of neurons in NASshell than in the NAS(core). The hybridization signals for PPE mRNA were observed in very few neurons of NASshell and in around half of the neurons in NAS(core). Besides this medio to lateral difference, GAD67 and PPE mRNAs were distributed in NAS(core) according to a rostro-caudal gradient, the content of both mRNAs being higher in the rostral part than the caudal part of this area.
Rogard
M
M
Laboratoire de Neurochimie-Anatomie, Institut des Neurosciences, URA 1488, Université P. et M. Curie, Paris, France.
Caboche
J
J
Julien
J F
JF
Besson
M J
MJ
D000818:Animals; D001345:Autoradiography; D004745:Enkephalins / Q000235:genetics*; D005968:Glutamate Decarboxylase / Q000235:genetics*; D006651:Histocytochemistry; D017403:In Situ Hybridization; D007527:Isoenzymes / Q000235:genetics; D008297:Male; D009714:Nucleus Accumbens / Q000378:metabolism*; D011498:Protein Precursors / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014018:Tissue Distribution
D004745:Enkephalins; D007527:Isoenzymes; D011498:Protein Precursors; D012333:RNA, Messenger; C033660:preproenkephalin; D005968:Glutamate Decarboxylase