title: Non-NMDA receptors within caudal ventrolateral medulla are involved in transmission of baroreflex of rats.
abstract: OBJECTIVE
  To investigate the role of non N-methyl-D-aspartate acid (non-NMDA) receptors within the caudal ventrolateral medulla (CVLM) in mediating the baroreflex.
  
  
  METHODS
  In urethane-anesthetized, paralyzed, and artificially ventilated rats, the effects of 6-cyano-7-nitroquinoxaline-2,3-dinoe (CNQX, a selective non-NMDA receptors antagonist) locally injected into the CVLM on the depressor responses evoked by aortic nerve stimulation and the barosensitivity of the rostral ventrolateral medulla (RVLM) barosensitive neurons were observed.
  
  
  RESULTS
  Bilateral microinjection of CNQX (200 pmol in 100 nL for each side) into the CVLM significantly (P<0.01) increased the blood pressure (BP) and heart rate, and markedly (P<0.01) attenuated the depressor response to the aortic nerve stimulation. CNQX (200 pmol in 100 nL) unilaterally injected into the CVLM significantly (P<0.01) increased the firing rate of the ipsilateral RVLM barosensitive neurons and reduced the inhibitory responses of neurons evoked by stimulation of aortic nerve and elevation of BP, and partially inhibited the neuronal cardiac cycle-related rhythm.
  
  
  CONCLUSIONS
  The CVLM played an important role in maintaining the tonic excitatory cardiovascular activities and transmitting the baroreceptor information via activation of non-NMDA receptors.
authors.affiliation: Department of Physiology, Second Military Medical University, Shanghai 200433, China. wangwz@smmu.edu.cn
authors.forename: Wei-Zhong
authors.initials: WZ
authors.lastname: Wang
authors.forename: Wen-Jun
authors.initials: WJ
authors.lastname: Yuan
authors.forename: Yan-Xia
authors.initials: YX
authors.lastname: Pan
authors.forename: Jie
authors.initials: J
authors.lastname: Bai
authors.forename: Mao-Yao
authors.initials: MY
authors.lastname: Liao
authors.forename: Chao-Shu
authors.initials: CS
authors.lastname: Tang
mesh_terms: D018750:6-Cyano-7-nitroquinoxaline-2,3-dione / Q000494:pharmacology*; D000818:Animals; D017704:Baroreflex / Q000187:drug effects* / Q000502:physiology; D001794:Blood Pressure / Q000187:drug effects; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology*; D006339:Heart Rate / Q000187:drug effects; D008297:Male; D008526:Medulla Oblongata / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017470:Receptors, Glutamate / Q000502:physiology
chemical_list: D018691:Excitatory Amino Acid Antagonists; D017470:Receptors, Glutamate; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione