title: Striatal preprotachykinin mRNA levels are regulated by stimulatory agents and dopamine D1 receptor manipulation in rodent organotypic slice cultures.
abstract: We have utilized an organotypic slice culture system to determine factors which directly influence the expression of striatal preprotachykinin (PPT) mRNA. Striatal slices were generated from 3-day-old male rat pups and cultured on Millicell-CM inserts in serum-containing media. Under these conditions, striatal PPT mRNA levels fell significantly (-55.7+/-6.2%) in slices cultured for 2 days in vitro (2DIV) as compared to slices placed in culture for 3 h (0DIV). However, striatal PPT mRNA expression did not decline further in 4DIV cultured slices (-59.6+/-7.1%). When 2DIV slices were exposed to combined high potassium (K(+), 10 mM) and forskolin (10 microM) stimulation for 3 h, PPT mRNA levels were increased within areas of the brain normally associated with tachykinin production. Application of the dopamine (DA) D1 receptor agonist SKF-38393 (10 microM) at 2DIV for 3 h also increased (+162.9+/-28.9%) PPT mRNA expression, but increases were localized within the striatum. SKF-38393-stimulated increases were completely blocked by the D1 antagonist SCH-23390 (10 microM), which alone had no effect on mRNA levels. However, a 3-h incubation with SKF-38393 on 0DIV slice cultures did not affect PPT mRNA expression whereas SCH-23390 decreased PPT message levels (-24.5+/-5.4%). These findings indicate that tachykinin gene expression is inducible within slice culture preparations and that the maintenance of normal striatal PPT mRNA levels depends on DA D1 receptor tone.
authors.affiliation: Cellular and Clinical Neurobiology Program, Department of Psychiatry and Behavioral Neurosciences, Wayne State University, School of Medicine, Detroit, MI 48201, USA.
authors.forename: B M
authors.initials: BM
authors.lastname: Campbell
authors.forename: P D
authors.initials: PD
authors.lastname: Walker
mesh_terms: D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine / Q000494:pharmacology; D000818:Animals; D001552:Benzazepines / Q000494:pharmacology; D001923:Brain Chemistry / Q000187:drug effects; D003342:Corpus Striatum / Q000502:physiology*; D018491:Dopamine Agonists / Q000494:pharmacology; D018492:Dopamine Antagonists / Q000494:pharmacology; D015870:Gene Expression / Q000187:drug effects / Q000502:physiology; D017403:In Situ Hybridization; D008297:Male; D009924:Organ Culture Techniques; D011498:Protein Precursors / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D017447:Receptors, Dopamine D1 / Q000502:physiology*; D015320:Tachykinins / Q000235:genetics*
chemical_list: D001552:Benzazepines; D018491:Dopamine Agonists; D018492:Dopamine Antagonists; D011498:Protein Precursors; D012333:RNA, Messenger; D017447:Receptors, Dopamine D1; D015320:Tachykinins; C044206:preprotachykinin; D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine