Role of inhibition in respiratory pattern generation
| Autor: | Yan Cui, Paul Hsu, Alexis Tashima, Jack L. Feldman, Wiktor A. Janczewski |
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| Rok vydání: | 2013 |
| Předmět: |
Male
medicine.medical_specialty Indoles Microinjections Diaphragm Glycine Biology Neurotransmission Vagotomy Inhibitory postsynaptic potential Bicuculline Functional Laterality Article Choline O-Acetyltransferase Rats Sprague-Dawley chemistry.chemical_compound Internal medicine Reflex medicine Animals GABA-A Receptor Agonists GABA-A Receptor Antagonists Botzinger complex GABAA receptor Electromyography Muscimol General Neuroscience Respiration Respiratory center Laryngeal Nerves Glycine Agents Neural Inhibition Vagus Nerve Strychnine Respiratory Center Rats Endocrinology chemistry Neuroscience medicine.drug |
| Zdroj: | The Journal of neuroscience : the official journal of the Society for Neuroscience. 33(13) |
| ISSN: | 1529-2401 |
| Popis: | Postsynaptic inhibition is a key element of neural circuits underlying behavior, with 20–50% of all mammalian (nongranule) neurons considered inhibitory. For rhythmic movements in mammals, e.g., walking, swimming, suckling, chewing, and breathing, inhibition is often hypothesized to play an essential rhythmogenic role. Here we study the role of fast synaptic inhibitory neurotransmission in the generation of breathing pattern by blocking GABAAand glycine receptors in the preBötzinger complex (preBötC), a site essential for generation of normal breathing pattern, and in the neighboring Bötzinger complex (BötC). The breathing rhythm continued following this blockade, but the lung inflation-induced Breuer–Hering inspiratory inhibitory reflex was suppressed. The antagonists were efficacious, as this blockade abolished the profound effects of the exogenously applied GABAAreceptor agonist muscimol or glycine, either of which under control conditions stopped breathing in vagus-intact or vagotomized, anesthetized, spontaneously breathing adult rats. In vagotomized rats, GABAAergic and glycinergic antagonists had little, if any, effect on rhythm. The effect in vagus-intact rats was to slow the rhythm to a pace equivalent to that seen after suppression of the aforementioned Breuer–Hering inflation reflex. We conclude that postsynaptic inhibition within the preBötC and BötC is not essential for generation of normal respiratory rhythm in intact mammals. We suggest the primary role of inhibition is in shaping the pattern of respiratory motor output, assuring its stability, and in mediating reflex or volitional apnea, but not in the generation of rhythm per se. |
| Databáze: | OpenAIRE |
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