title: Nociceptive neurons differentially express fast and slow T-type Ca²⁺ currents in different types of diabetic neuropathy.
abstract: T-type Ca²⁺ channels are known as important participants of nociception and their remodeling contributes to diabetes-induced alterations of pain sensation. In this work we have established that about 30% of rat nonpeptidergic thermal C-type nociceptive (NTCN) neurons of segments L4-L6 express a slow T-type Ca²⁺ current (T-current) while a fast T-current is expressed in the other 70% of these neurons. Streptozotocin-induced diabetes in young rats resulted in thermal hyperalgesia, hypoalgesia, or normalgesia 5-6 weeks after the induction. Our results show that NTCN neurons obtained from hyperalgesic animals do not express the slow T-current. Meanwhile, the fraction of neurons expressing the slow T-current did not significantly change in the hypo- and normalgesic diabetic groups. Moreover, the peak current density of fast T-current was significantly increased only in the neurons of hyperalgesic group. In contrast, the peak current density of slow T-current was significantly decreased in the hypo- and normalgesic groups. Experimental diabetes also resulted in a depolarizing shift of steady-state inactivation of fast T-current in the hyperalgesic group and slow T-current in the hypo- and normalgesic groups. We suggest that the observed changes may contribute to expression of different types of peripheral diabetic neuropathy occurring during the development of diabetes mellitus.
authors.affiliation: International Center of Molecular Physiology of National Academy of Sciences of Ukraine, 4 Bogomoletz Street., Kyiv 01024, Ukraine ; State Key Laboratory of Molecular and Cellular Biology, Bogomoletz Institute of Physiology of National Academy of Sciences of Ukraine, 4 Bogomoletz Street, Kyiv 01024, Ukraine.
authors.forename: Eugen V
authors.initials: EV
authors.lastname: Khomula
authors.affiliation: State Key Laboratory of Molecular and Cellular Biology, Bogomoletz Institute of Physiology of National Academy of Sciences of Ukraine, 4 Bogomoletz Street, Kyiv 01024, Ukraine.
authors.forename: Anya L
authors.initials: AL
authors.lastname: Borisyuk
authors.affiliation: State Key Laboratory of Molecular and Cellular Biology, Bogomoletz Institute of Physiology of National Academy of Sciences of Ukraine, 4 Bogomoletz Street, Kyiv 01024, Ukraine.
authors.forename: Viacheslav Y
authors.initials: VY
authors.lastname: Viatchenko-Karpinski
authors.affiliation: State Key Laboratory of Molecular and Cellular Biology, Bogomoletz Institute of Physiology of National Academy of Sciences of Ukraine, 4 Bogomoletz Street, Kyiv 01024, Ukraine.
authors.forename: Andrea
authors.initials: A
authors.lastname: Briede
authors.affiliation: International Center of Molecular Physiology of National Academy of Sciences of Ukraine, 4 Bogomoletz Street., Kyiv 01024, Ukraine ; State Key Laboratory of Molecular and Cellular Biology, Bogomoletz Institute of Physiology of National Academy of Sciences of Ukraine, 4 Bogomoletz Street, Kyiv 01024, Ukraine.
authors.forename: Pavel V
authors.initials: PV
authors.lastname: Belan
authors.affiliation: International Center of Molecular Physiology of National Academy of Sciences of Ukraine, 4 Bogomoletz Street., Kyiv 01024, Ukraine ; State Key Laboratory of Molecular and Cellular Biology, Bogomoletz Institute of Physiology of National Academy of Sciences of Ukraine, 4 Bogomoletz Street, Kyiv 01024, Ukraine.
authors.forename: Nana V
authors.initials: NV
authors.lastname: Voitenko
mesh_terms: D000465:Algorithms; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D020747:Calcium Channels, T-Type / Q000096:biosynthesis* / Q000378:metabolism / Q000502:physiology*; D003921:Diabetes Mellitus, Experimental / Q000473:pathology; D003929:Diabetic Neuropathies / Q000503:physiopathology*; D005727:Ganglia, Spinal / Q000503:physiopathology; D006358:Hot Temperature; D006930:Hyperalgesia / Q000503:physiopathology; D007091:Image Processing, Computer-Assisted; D007700:Kinetics; D009619:Nociceptors / Q000502:physiology*; D010146:Pain / Q000503:physiopathology; D018408:Patch-Clamp Techniques; D037121:Plant Lectins; D051381:Rats; D011984:Sensory Receptor Cells / Q000502:physiology*
chemical_list: C509958:Cacna1h protein, rat; D020747:Calcium Channels, T-Type; C045475:Griffonia simplicifolia lectins; D037121:Plant Lectins