title: [Roles of ACh receptors in the effects of corticosterone on presympathetic neurons in the ventrolateral medulla of rats].
abstract: OBJECTIVE
  To investigate the roles of acetylcholine (ACh) receptors in the rapid effects of corticosterone (CORT) on the presympathetic neurons in the rostral ventrolateral medulla (RVLM) of rats, and study the non-genomic mechanism of glucocorticoid (GC) in the integration of sympathetic cardiovascular activity.
  
  
  METHODS
  The effects of microelectrophoresis of CORT on the discharge of the presympathetic neurons in the RVLM were observed by extracellular recording in urethane-anaesthetized rats. The responses of atropine (a blocker for M type of ACh receptor, ATR), d-tubocurarine (a blocker for N1 type of ACh receptor, d-TC) and hexamethonium (a blocker for N2 type of ACh receptor, C6) to the effects of CORT on the presympathetic neurons were investigated respectively.
  
  
  RESULTS
  Totally 33 presympathetic neurons in the RVLM were recorded. Among them the firing rate of 25 (76%) presympathetic neurons was increased by microelectrophoresis of CORT. The effects of CORT were also positively correlated with the currents. In the other 8 presympathetic neurons, had was shown no effect after microelectrophoresis of CORT. In 10 presympathetic neurons, which discharge was increased by CORT, microelectrophoresis of ATR decreased the firing rate of these presympathetic neurons (P < 0.05), and did not fully block the excitatory effect induced by CORT. In both 7 and 6 presympathetic neurons, application of d-TC and C6 had no effect on these neurons respectively, and did not fully block the excitatory effect induced by CORT.
  
  
  CONCLUSIONS
  CORT had rapid excitatory effects on the presympathetic neurons in the RVLM, which effect might be independent on ACh receptors.
authors.affiliation: Department of Physiology, The Second Military Medical University, Shanghai 200433, China.
authors.forename: Wei-Zhong
authors.initials: WZ
authors.lastname: Wang
authors.forename: Xue-Mei
authors.initials: XM
authors.lastname: Wang
authors.forename: Wei-Fang
authors.initials: WF
authors.lastname: Rong
authors.forename: Ji-Jang
authors.initials: JJ
authors.lastname: Wang
authors.forename: Wen-Jun
authors.initials: WJ
authors.lastname: Yuan
mesh_terms: D000818:Animals; D018680:Cholinergic Antagonists / Q000494:pharmacology; D003345:Corticosterone / Q000494:pharmacology*; D046209:Electrophoresis, Microchip; D008297:Male; D008526:Medulla Oblongata / Q000187:drug effects / Q000502:physiology*; D003473:Neuromuscular Nondepolarizing Agents / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects* / Q000502:physiology; D018733:Nicotinic Antagonists / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D011950:Receptors, Cholinergic / Q000502:physiology*
chemical_list: D018680:Cholinergic Antagonists; D003473:Neuromuscular Nondepolarizing Agents; D018733:Nicotinic Antagonists; D011950:Receptors, Cholinergic; D003345:Corticosterone