The action of the A1 noradrenergic region on the activity of subfornical organ neurons in the rat
| Autor: | Junichi Tanaka, Norifumi Mashiko, Satoko Hatakenaka, Masahiko Nomura, Shigeko Fujisawa, Ayako Kawakami |
|---|---|
| Rok vydání: | 2002 |
| Předmět: |
Male
medicine.medical_specialty Baroreceptor Pressoreceptors Stimulation Inhibitory postsynaptic potential Norepinephrine Phentolamine Receptors Adrenergic alpha-1 Internal medicine medicine Animals Premovement neuronal activity Rats Wistar Neurons Medulla Oblongata business.industry General Neuroscience Electric Stimulation Subfornical organ Rats medicine.anatomical_structure Endocrinology Medulla oblongata Excitatory postsynaptic potential business Neuroscience Subfornical Organ medicine.drug |
| Zdroj: | Neuroscience Letters. 332:41-44 |
| ISSN: | 0304-3940 |
| DOI: | 10.1016/s0304-3940(02)00913-8 |
| Popis: | Electrical stimulation of the A1 noradrenergic region of the ventrolateral medulla produced synatic excitation (n = 19, 9%), inhibition (n = 5, 2%) or no effect (n = 184, 89%) in the activity of a total of 208 neurons in the subfornical organ (SFO) in male rats under urethane anesthesia. Almost all (n = 18) of the excitatory responses (n = 19) were blocked by microiontophoretically-applied phentolamine, an alpha-adrenergic antagonist, but not by timolol, a beta-adrenergic antagonist. The inhibitory response of all the neurons (n = 5) tested was prevented by iontophoretically applied timolol, but not by phentolamine. Approximately a half (n = 9) of SFO neurons that demonstrated the excitatory response to A1 region stimulation exhibited an increase in neuronal activity in response to hemorrhage (10 ml/kg b.w.t.), while remaining neurons (n = 10) were unresponsive. Hemorrhage did not cause any change in the activity of all the neurons (n = 5) that demonstrated the inhibitory response to A1 region stimulation. These results suggest that the medullary inputs to approximately 10% of SFO neurons tested are mediated by alpha-adrenergic excitatory and beta-adrenergic inhibitory pathways, and imply that a part of the excitatory pathways may transmit the peripheral baroreceptor information. |
| Databáze: | OpenAIRE |
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