Intermittent hypercapnic hypoxia effects on the nicotinic acetylcholine receptors in the developing piglet hippocampus and brainstem
| Autor: | Atqiya Aishah, Arunnjah Vivekanandarajah, Karen A. Waters, Rita Machaalani |
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| Rok vydání: | 2017 |
| Předmět: |
Male
0301 basic medicine medicine.medical_specialty Swine Receptors Nicotinic Toxicology Hippocampus Hypercapnia Nicotine 03 medical and health sciences 0302 clinical medicine Internal medicine medicine Animals Hypoxia Medulla Chemistry General Neuroscience Solitary tract Sudden infant death syndrome body regions Protein Subunits Nicotinic acetylcholine receptor 030104 developmental biology Endocrinology Nicotinic agonist Medulla oblongata Swine Miniature Female Brainstem 030217 neurology & neurosurgery Brain Stem medicine.drug |
| Zdroj: | NeuroToxicology. 60:23-33 |
| ISSN: | 0161-813X |
| Popis: | This study investigated the effects of acute (1 day) vs repeated (4 days) exposure to intermittent hypercapnic hypoxia (IHH) on the immunohistochemical expression of α2, α3, α5, α7, α9 and β2 nicotinic acetylcholine receptor (nAChR) subunits in the developing piglet hippocampus and brainstem medulla, and how prior nicotine exposure alters the response to acute IHH. Five piglet groups included: 1 day IHH (1D IHH, n = 9), 4 days IHH (4D IHH, n = 8), controls exposed only to air cycles for 1 day (1D Air, n = 6) or 4 days (4D Air, n = 5), and pre-exposed to nicotine for 13 days prior to 1 day IHH (Nic + 1D IHH, n = 7). The exposure period alternated 6 min of HH (8%O 2 , 7%CO 2 , balance N 2 ) and 6 min of air over 48 min, while controls were switched from air-to-air. Results showed that: 1. repeated IHH induces more changes in nAChR subunit expression than acute IHH in both the hippocampus and brainstem medulla, 2. In the hippocampus, α2 and β2 changed the most (increased) following IHH and the CA3, CA2 and DG were mostly affected. In the brainstem medulla, α2, α5, α9 and β2 were changed (decreased) in most nuclei with the hypoglossal and nucleus of the solitary tract being mostly affected. 3. Pre-exposure to nicotine enhanced the changes in the hippocampus but dampened those in the brainstem medulla. These findings indicate that the nAChRs (predominantly with the α2/β2 complex) are affected by IHH in critical hippocampal and brainstem nuclei during early brain development, and that pre-exposure to nicotine alters the pattern of susceptibility to IHH. |
| Databáze: | OpenAIRE |
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