Academic Journal
Post‐activation depression from primary afferent depolarization (PAD) produces extensor H‐reflex suppression following flexor afferent conditioning
| العنوان: | Post‐activation depression from primary afferent depolarization (PAD) produces extensor H‐reflex suppression following flexor afferent conditioning |
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| المؤلفون: | Metz, Krista, Matos, Isabel Concha, Hari, Krishnapriya, Bseis, Omayma, Afsharipour, Babak, Lin, Shihao, Singla, Rahul, Fenrich, Keith K., Li, Yaqing, Bennett, David J., Gorassini, Monica A. |
| المصدر: | The Journal of Physiology ; volume 601, issue 10, page 1925-1956 ; ISSN 0022-3751 1469-7793 |
| بيانات النشر: | Wiley |
| سنة النشر: | 2023 |
| المجموعة: | Wiley Online Library (Open Access Articles via Crossref) |
| الوصف: | Suppression of the extensor H‐reflex by flexor afferent conditioning is thought to be produced by a long‐lasting inhibition of extensor Ia afferent terminals via GABA A receptor‐activated primary afferent depolarization (PAD). Given the recent finding that PAD does not produce presynaptic inhibition of Ia afferent terminals, we examined in 28 participants if H‐reflex suppression is instead mediated by post‐activation depression of the extensor Ia afferents triggered by PAD‐evoked spikes and/or by a long‐lasting inhibition of the extensor motoneurons. A brief conditioning vibration of the flexor tendon suppressed both the extensor soleus H‐reflex and the tonic discharge of soleus motor units out to 150 ms following the vibration, suggesting that part of the H‐reflex suppression during this period was mediated by postsynaptic inhibition of the extensor motoneurons. When activating the flexor afferents electrically to produce conditioning, the soleus H‐reflex was also suppressed but only when a short‐latency reflex was evoked in the soleus muscle by the conditioning input itself. In mice, a similar short‐latency reflex was evoked when optogenetic or afferent activation of GABAergic (GAD2 + ) neurons produced a large enough PAD to evoke orthodromic spikes in the test Ia afferents, causing post‐activation depression of subsequent monosynaptic EPSPs. The long duration of this post‐activation depression and related H‐reflex suppression (seconds) was similar to rate‐dependent depression that is also due to post‐activation depression. We conclude that extensor H‐reflex inhibition by brief flexor afferent conditioning is produced by both post‐activation depression of extensor Ia afferents and long‐lasting inhibition of extensor motoneurons, rather than from PAD inhibiting Ia afferent terminals. image Key points Suppression of extensor H‐reflexes by flexor afferent conditioning was thought to be mediated by GABA A receptor‐mediated primary afferent depolarization (PAD) shunting action potentials in the Ia afferent ... |
| نوع الوثيقة: | article in journal/newspaper |
| اللغة: | English |
| DOI: | 10.1113/jp283706 |
| DOI: | 10.1113/JP283706 |
| الاتاحة: | http://dx.doi.org/10.1113/jp283706 https://onlinelibrary.wiley.com/doi/pdf/10.1113/JP283706 https://physoc.onlinelibrary.wiley.com/doi/pdf/10.1113/JP283706 |
| Rights: | http://creativecommons.org/licenses/by/4.0/ |
| رقم الانضمام: | edsbas.5DA4EA23 |
| قاعدة البيانات: | BASE |
| DOI: | 10.1113/jp283706 |
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