کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
8292626 1536735 2018 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Modulation by orexin A of spontaneous excitatory and inhibitory transmission in adult rat spinal substantia gelatinosa neurons
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
Modulation by orexin A of spontaneous excitatory and inhibitory transmission in adult rat spinal substantia gelatinosa neurons
چکیده انگلیسی
Hypothalamic neuropeptides, orexins A and B, differently inhibit nociceptive behavior. This difference is possibly due to a distinction between orexins A and B in modulating synaptic transmission in spinal substantia gelatinosa (SG) neurons that play a pivotal role in regulating nociceptive transmission. Although we previously reported a modulatory action of orexin B on synaptic transmission in adult rat SG neurons, it has not been fully examined how the transmission is affected by orexin A. The present study examined the effects of orexin A on spontaneous excitatory and inhibitory transmission in SG neurons of adult rat spinal cord slices by using the whole-cell patch-clamp technique. Like orexin B, orexin A produced an inward current at −70 mV and/or increased the frequency of spontaneous excitatory postsynaptic current without changing its amplitude. Half-maximal effective concentration values for their effects were 0.0045 and 0.030 μM, respectively; the former value was four-fold smaller than that of orexin B while the latter value was comparable to that of orexin B. Orexin A enhanced not only glycinergic but also GABAergic transmission, although only glycinergic transmission was facilitated by orexin B in the majority of neurons tested. Orexin A activities were inhibited by an orexin-1 receptor antagonist (SB334867) but not an orexin-2 receptor antagonist (JNJ10397049), as different from orexin B whose activation was depressed by JNJ10397049 but not SB334867. These results indicate that orexin A has a different action from orexin B in SG neurons in efficacy for inward current production and in GABAergic transmission enhancement, possibly owing to orexin-1 but not orexin-2 receptor activation. This difference could contribute to at least a part of the distinction between orexins A and B in antinociceptive effects.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biochemical and Biophysical Research Communications - Volume 501, Issue 1, 18 June 2018, Pages 100-105
نویسندگان
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