Decreased neuronal excitability in hippocampal neurons of mice exposed to cyclic hypoxia
| العنوان: | Decreased neuronal excitability in hippocampal neurons of mice exposed to cyclic hypoxia |
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| المؤلفون: | Gabriel G. Haddad, Xiang Q. Gu |
| المصدر: | Journal of Applied Physiology. 91:1245-1250 |
| بيانات النشر: | American Physiological Society, 2001. |
| سنة النشر: | 2001 |
| مصطلحات موضوعية: | Atmosphere Exposure Chambers, medicine.medical_specialty, Patch-Clamp Techniques, Physiology, Ratón, Central nervous system, Action Potentials, Hippocampal formation, Biology, Hippocampus, Sodium Channels, Mice, Physiology (medical), Internal medicine, medicine, Animals, Patch clamp, Hypoxia, Brain, Neurons, Sodium channel, Sodium, Hypoxia (medical), Oxygen, Electrophysiology, Endocrinology, medicine.anatomical_structure, Neuron, medicine.symptom |
| الوصف: | To study the physiological effects of chronic intermittent hypoxia on neuronal excitability and function in mice, we exposed animals to cyclic hypoxia for 8 h daily (12 cycles/h) for ∼4 wk, starting at 2–3 days of age, and examined the properties of freshly dissociated hippocampal neurons in vitro. Compared with control (Con) hippocampal CA1 neurons, exposed (Cyc) neurons showed action potentials (AP) with a smaller amplitude and a longer duration and a more depolarized resting membrane potential. They also have a lower rate of spontaneous firing of AP and a higher rheobase. Furthermore, there was downregulation of the Na+ current density in Cyc compared with Con neurons (356.09 ± 54.03 pA/pF in Cyc neurons vs. 508.48 ± 67.30 pA/pF in Con, P < 0.04). Na+ channel characteristics, including activation, steady-state inactivation, and recovery from inactivation, were similar in both groups. The deactivation rate, however, was much larger in Cyc than in Con (at −100 mV, time constant for deactivation = 0.37 ± 0.04 ms in Cyc neurons and 0.18 ± 0.01 ms in Con neurons). We conclude that the decreased neuronal excitability in mice neurons treated with cyclic hypoxia is due, at least in part, to differences in passive properties (e.g., resting membrane potential) and in Na+ channel expression and/or regulation. We hypothesize that this decreased excitability is an adaptive response that attempts to decrease the energy expenditure that is used for adjusting disturbances in ionic homeostasis in low-O2conditions. |
| تدمد: | 1522-1601 8750-7587 |
| الوصول الحر: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::a84b44f340347c26e5f0925eee9de311Test https://doi.org/10.1152/jappl.2001.91.3.1245Test |
| حقوق: | OPEN |
| رقم الانضمام: | edsair.doi.dedup.....a84b44f340347c26e5f0925eee9de311 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 15221601 87507587 |
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