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Interaction of GABA and glutamate inputs in the dorsal motor nucleus of the vagus
Author(s) -
Babic Tanja,
Browning Kirsteen N,
Travagli R Alberto
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.623.1
Subject(s) - dorsal motor nucleus , bicuculline , glutamatergic , microinjection , neuroscience , gabaergic , tonic (physiology) , glutamate receptor , gaba receptor antagonist , bursting , vagus nerve , chemistry , biology , endocrinology , gabaa receptor , inhibitory postsynaptic potential , receptor , biochemistry , stimulation
The dorsal motor nucleus of the vagus (DMV) is pivotal in the regulation of gastric motility. Microinjection of bicuculline (BIC) into the DMV increases gastric motility whereas kynurenic acid (KYN) has no effect unless preceded by microinjection of BIC. The aims of this study were to determine the effects of BIC and KYN on DMV neurons in a slice preparation. Using whole cell patch clamp recordings in 67 DMV neurons, we investigated the effects of BIC and KYN, or their combination, on the firing rate of DMV neurons. Perfusion with BIC increased the firing frequency in 51% of neurons and decreased it in 30%, leaving the remaining neurons unaffected. Following application of BIC, KYN either decreased (60%) or increased (40%) their firing frequency. When KYN was applied first, the firing rate was decreased in 57% and increased 17% neurons. Further perfusion with BIC had no additional effect in most neurons that responded to KYN. These data confirm in vivo studies demonstrating that DMV neurons are under tonic GABAergic control. In contrast to these in vivo studies, though, DMV neurons also responded to KYN, suggesting that they receive tonic glutamatergic input. These data suggest that those DMV neurons regulating gastric motility may be the ones affected by a tonic GABAergic input, whereas the circuits that receive a glutamatergic input may be the ones involved in functions other that gastric motility. Supported by DK 55530