Role of GABAA receptors in rat hindbrain nuclei controlling gastric motor function

被引:1
作者
Sivarao, DV [1 ]
Krowicki, ZK [1 ]
Hornby, PJ [1 ]
机构
[1] Louisiana State Univ, Med Ctr, Dept Pharmacol & Expt Therapeut, New Orleans, LA 70112 USA
关键词
motility; raphe nuclei; vagal nuclei; vagus;
D O I
暂无
中图分类号
R57 [消化系及腹部疾病];
学科分类号
摘要
It has been shown in cats that gastric motor control by the dorsal vagal complex and nucleus ambiuus is under a tonic GABAergic influence. Since much more work has been performed in rats to define vago-vagal reflexes controlling gastrointestinal function, an understanding of the potential inhibition by candidate neurotransmitters such as GABA (gamma aminobutyric acid) in the rat dorsal vagal complex (DVC) is essential to assess. Multiple-barrelled micropipettes were used to apply to the dorsal vagal complex the GABA(A) antagonist, bicuculline methiodide (0.1-1 nmol), and a GABA(A) agonist, muscimol (10 nmol) prior to micro-injection of the GABA(A) antagonist. Micro-injections of bicuculline (353 pmol and 1 nmol), which were localized primarily in the dorsal motor nucleus of the vagus, produced significant increases in intragastric pressure and pyloric motility. These responses were abolished by vagotomy and by a prior micro-injection of muscimol. To determine whether GABAergic blockade in the dorsal vagal complex results in gastric motor excitation through excitatory amino acid receptors, kynurenic acid (5 nmol), a kainate/NMDA (N-methyl D-aspartic acid) receptor antagonist, was micro-injected prior to bicuculline. This abolished the increase in gastric motor function normally evoked by bicuculline. In the other two important hindbrain nuclei controlling gastric function, the nucleus raphe obscurus and nucleus ambiguus, bicuculline (353 pmol) significantly increased intragastric pressure via vagally mediated pathways. These data demonstrate that all three rat hindbrain nuclei known to influence gastric function via the vagus nerve are under tonic GABAergic control. In addition, in the dorsal vagal complex, relief from GABAergic inhibition results in increases in gastric motor function through kainate/NMDA receptor-mediated excitation.
引用
收藏
页码:305 / 313
页数:9
相关论文
共 30 条
  • [21] TRH STIMULATION AND L-GLUTAMIC ACID INHIBITION OF PROXIMAL GASTRIC MOTOR-ACTIVITY IN THE RAT DORSAL VAGAL COMPLEX
    RAYBOULD, HE
    JAKOBSEN, LJ
    NOVIN, D
    TACHE, Y
    [J]. BRAIN RESEARCH, 1989, 495 (02) : 319 - 328
  • [22] VAGOVAGAL REFLEX CONTROL OF DIGESTION - AFFERENT MODULATION BY NEURAL AND ENDONEUROCRINE FACTORS
    ROGERS, RC
    MCTIGUE, DM
    HERMANN, GE
    [J]. AMERICAN JOURNAL OF PHYSIOLOGY-GASTROINTESTINAL AND LIVER PHYSIOLOGY, 1995, 268 (01): : G1 - G10
  • [23] AFFERENT-PROJECTIONS TO THE DORSAL MOTOR NUCLEUS OF THE VAGUS
    ROGERS, RC
    KITA, H
    BUTCHER, LL
    NOVIN, D
    [J]. BRAIN RESEARCH BULLETIN, 1980, 5 (04) : 365 - 373
  • [24] Intracisternal antisense oligonucleotides to TRH receptor abolish TRH-evoked gastric motor excitation
    Sivarao, DV
    Krowicki, ZK
    Abrahams, TP
    Hornby, PJ
    [J]. AMERICAN JOURNAL OF PHYSIOLOGY-GASTROINTESTINAL AND LIVER PHYSIOLOGY, 1997, 272 (06): : G1372 - G1381
  • [25] INTERACTION OF HYPOTHALAMIC GABA-A AND EXCITATORY AMINO-ACID RECEPTORS CONTROLLING HEART-RATE IN RATS
    SOLTIS, RP
    DIMICCO, JA
    [J]. AMERICAN JOURNAL OF PHYSIOLOGY, 1991, 261 (02): : R427 - R433
  • [26] GLUTAMATE AND GABA-MEDIATED SYNAPTIC CURRENTS IN NEURONS OF THE RAT DORSAL MOTOR NUCLEUS OF THE VAGUS
    TRAVAGLI, RA
    GILLIS, RA
    ROSSITER, CD
    VICINI, S
    [J]. AMERICAN JOURNAL OF PHYSIOLOGY, 1991, 260 (03): : G531 - G536
  • [27] GABA RECEPTORS IN THE DORSAL MOTOR NUCLEUS OF THE VAGUS INFLUENCE FELINE LOWER ESOPHAGEAL SPHINCTER AND GASTRIC FUNCTION
    WASHABAU, RJ
    FUDGE, M
    PRICE, WJ
    BARONE, FC
    [J]. BRAIN RESEARCH BULLETIN, 1995, 38 (06) : 587 - 594
  • [28] HINDBRAIN GABA RECEPTORS INFLUENCE PARASYMPATHETIC OUTFLOW TO THE STOMACH
    WILLIFORD, DJ
    ORMSBEE, HS
    NORMAN, W
    HARMON, JW
    GARVEY, TQ
    DIMICCO, JA
    GILLIS, RA
    [J]. SCIENCE, 1981, 214 (4517) : 193 - 194
  • [29] ONTOGENY AND DISTRIBUTION OF GABA-A RECEPTORS IN RAT BRAIN-STEM AND ROSTRAL BRAIN-REGIONS
    XIA, Y
    HADDAD, GG
    [J]. NEUROSCIENCE, 1992, 49 (04) : 973 - 989
  • [30] TRH ANALOG MICROINJECTED INTO SPECIFIC MEDULLARY NUCLEI STIMULATES GASTRIC SEROTONIN SECRETION IN RATS
    YANG, H
    STEPHENS, RL
    TACHE, Y
    [J]. AMERICAN JOURNAL OF PHYSIOLOGY, 1992, 262 (02): : G216 - G222