title: Effects of oxotremorine on neuronal RNA and chromatin in thalamic cholinoceptive sites.
abstract: Neuronal nucleic acid responses were examined within the rat thalamic ventrobasal nuclear complex (VBC) and nucleus reticularis (NR) following single intraperitoneal injections of the central muscarinic-cholinergic (M2) receptor agonist oxotremorine (0.1, 0.7, or 1.0 mg/kg). After stoichiometric azure B and Feulgen staining of brain sections, scanning-integrating cytophotometry was used to quantify azure B-ribonucleic acid (RNA) content, Feulgen-DNA levels, and changes in the susceptibility of chromatin to Feulgen acid hydrolysis (F-DNA yield) of neurons on an individual basis. Changes in neuronal nucleolar volume were also determined histometrically. Within the VBC, oxotremorine produced marked dose-dependent elevations in neuronal RNA content and nucleolar volume with increased F-DNA yield (chromatin activation) in a proportion of VBC neurons. In contrast, within the NR, oxotremorine elicited reductions in RNA levels, F-DNA yield and nucleolar volume. The data demonstrate that oxotremorine-induced central muscarinic receptor stimulation is associated with metabolic correlates of thalamic VBC neuroexcitation and NR neuron depression. The overall study lends further credence to the hypothesis that muscarinic-cholinergic mechanisms are operative within the mammalian thalamus.
authors: Department of Biology, Pennsylvania State University, University Park 16802.
authors: L J
authors: LJ
authors: Martin
authors: J D
authors: JD
authors: Morse
authors: G A
authors: GA
authors: Pritchard
authors: Y H
authors: YH
authors: Kim
authors: A
authors: A
authors: Anthony
mesh_terms: D000818:Animals; D002843:Chromatin / Q000187:drug effects / Q000648:ultrastructure*; D008297:Male; D009474:Neurons / Q000166:cytology* / Q000187:drug effects; D010095:Oxotremorine / Q000494:pharmacology*; D012313:RNA / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D011950:Receptors, Cholinergic / Q000187:drug effects; D012016:Reference Values; D013194:Staining and Labeling; D013788:Thalamus / Q000166:cytology* / Q000187:drug effects
chemical_list: D002843:Chromatin; D011950:Receptors, Cholinergic; D010095:Oxotremorine; D012313:RNA