ISSN 2415-3060 (print), ISSN 2522-4972 (online)
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JMBS 2020, 5(4): 86–92
https://doi.org/10.26693/jmbs05.04.086
Experimental Medicine and Morphology

Influence of Androgen Deficiency on the Function of the Internal Neural Spinal Pool

Rodinsky O. G., Tkachenko S. S., Marazha I. O.
Abstract

The purpose of the study was to analyze the features of bioelectric activity of dorsal horn interneurons of the gray matter of the spinal cord under conditions of prolonged hypoandrogenemia by analyzing evoked potentials of the dorsal surface of the spinal cord. Materials and methods. The study was performed on Wistar male rats 5-6 months of age and weighing 180-260 g, which were divided into experimental (n=18) and control (n = 13) groups. Androgenemia was modeled by bilateral orchectomy. The dorsal root of L5 was stimulated by bipolar electrodes. The potentials of the dorsal surface of the spinal cord was evoked in the focus of maximum activity using a monopolar electrode. Threshold and chronoxia, latent period duration, total potentials of the dorsal surface of the spinal cord duration, duration and amplitude of afferent peak, N1, N2, N3 components and P-waves were studied, as well as presynaptic inhibition processes using paired stimulus method with intervals between 2 and 1000 ms. Results and discussion. The occurrence threshold for potentials of the dorsal surface of the spinal cord increased to 230.77±2.33% (p<0.001). Chronoxia in animals with experimental hypoandrogenemia decreased by 18.28±2.31% (p<0.001). In animals with hypoandrogenemia, the afferent peak amplitude increased by 98.33±5.88%, N1 increased by 51.08±2.86%, N2 increased by 49.64±2.40%, N3 increased by 207.41±4.82%. The P-wave amplitude showed an upward trend (p> 0.05). The latent period of occurrence of potentials of the dorsal surface of the spinal cord decreased almost twice (47.27±3.85%). The overall duration of the potentials of the dorsal surface of the spinal cord decreased to 78.40±3.32% (p <0.001). The P-wave duration decreased to 73.72±3.2% of the control value. Other components of the potentials of the dorsal surface of the spinal cord did not undergo any significant changes. When using pairwise stimuli, the rate of increase of the amplitude of the N1 component of the second response in animals with orchectomy lagged behind the values of the control group, especially at intervals from 6 to 50 ms. Conclusion. The results showed the development of multidirectional processes in the structures of the posterior horn of the spinal cord under conditions of experimental hypoandrogenemia. Thus, despite the increase in the occurrence of potentials of the dorsal surface of the spinal cord in the animals of the experimental group, probably by reducing the excitability of the primary afferents, the activity of the interneuron pool increases, primarily due to the inhibition of segmental and non-segmental interneurons, and some increase in the activity of the neuron amplitude of the P-wave. There is a slowdown of signals with a follow-up frequency exceeding 20 Hz with regard to nerve transmission in the structures of the posterior horn of the spinal cord, then under conditions of a long-term testosterone deficiency.

Keywords: spinal cord, dorsal horn, interneuron, androgen

Full text: PDF (Ukr) 290K

References
  1. Traub RJ, Ji Y. Sex differences and hormonal modulation of deep tissue pain. Front Neuroendocrinol. 2013; 34(4): 350-66. https://doi.org/10.1016/j.yfrne.2013.07.002. https://www.ncbi.nlm.nih.gov/pubmed/23872333. https://www.ncbi.nlm.nih.gov/pmc/articles/3830473
  2. Lumbroso S, Sandillon F, Georget V, Lobaccaro JM, Brinkmann AO, Privat A, et al. Immunohistochemical localization and immunoblotting of androgen receptor in spinal neurons of male and female rats. Eur J Endocrinol. 1996 May; 134(5): 626-32. https://doi.org/10.1530/eje.0.1340626. https://www.ncbi.nlm.nih.gov/pubmed/8664984
  3. Evrard HC, Balthazart J. Aromatase (estrogen synthase) activity in the dorsal horn of the spinal cord: functional implications. Ann N Y Acad Sci. 2003 Dec; 1007: 263-71. https://doi.org/10.1196/annals.1286.025. https://www.ncbi.nlm.nih.gov/pubmed/14993059
  4. Hau M, Dominguez OA, Evrard HC. Testosterone reduces responsiveness to nociceptive stimuli in a wild bird. Horm Behav. 2004 Aug; 46(2): 165-70. https://doi.org/10.1016/j.yhbeh.2004.02.007. https://www.ncbi.nlm.nih.gov/pubmed/15256306
  5. Rodyns'kyy OH. Neyrofiziolohichnyy analiz funktsionuvannya spynnoho mozku v umovakh osoblyvo vysokoyi zbudlyvosti ta mozhlyvosti yiyi korektsiyi [Neurophysiological analysis of spinal cord function in conditions of particularly high excitability and the possibility of its correction]. Abstr. Dr. Sci. (Med.). Donets'k; 2007. 38 s. [Ukrainian]
  6. Shugurov OO. Potentsialy dorsal'noy poverkhnosti pri stimulyatsii kozhnykh pokrovov nogi koshki [Potentials of the dorsal surface during stimulation of the skin of a cat's leg]. Vísnik Dnípropetrovs'kogo uníversitetu. 2006; 14(1): 210-7. [Russian]
  7. Shuhurov OO. Chastotni parametry masovykh potentsialiv spynnoho mozku pry rytmichniy stymulyatsiyi shkirnykh nerviv [Frequency parameters of mass potentials of the spinal cord during rhythmic stimulation of cutaneous nerves]. Visnyk Dnipropetrovsʹkoho universytetu. 2007; 15(1): 209-15. [Ukrainian] https://doi.org/10.15421/010737
  8. Shugurov OA. Vyzvannyye potentsialy spinnogo mozga [Evoked potentials of the spinal cord]. D: Nauka í osvíta; 2006. 319 s. [Russian]
  9. Shuhurov OO, Shuhurov OA. Yssledovanye voznyknovenyya pozdnykh pozytyvnykh voln PDP [Investigation of the occurrence of late positive waves of RAP]. Visnyk Dnipropetrovs'koho universytetu (Biolohiya, Ekolohiya). 2002; 1(10): 149-54. [Russian]. https://doi.org/10.15421/021623
  10. Makiy YeA, Nerush PA, Rodinskiy AG. Parametry potentsiala dorsal'noy poverkhnosti spinnogo mozga krys pri eksperimental'nom gipertireoze [Parameters of the potential of the dorsal surface of the spinal cord of rats in experimental hyperthyroidism]. Neyrofiziologiya. 2001; 33(4): 279-85. [Russian]
  11. Rodyns'kyy OH, Tkachenko SS. Aktyvnist interneyronnykh puliv spynnoho mozku za umov eksperymental'noyi menopauzy [Activity of interneuronal spinal cord pools under experimental menopause]. Fiziolohichnyy zhurnal. 2015; 61(5): 28-34. [Ukrainian] https://doi.org/10.15407/fz61.05.028. https://www.ncbi.nlm.nih.gov/pubmed/26845841
  12. Dmitriyeva OA, Sherstyuk BV. Vliyaniye stress-indutsirovannogo snizheniya urovnya testosterona na gistokhimicheskiye izmeneniya polovykh organov krys [The effect of stress-induced decrease in testosterone levels on histochemical changes in rat genital organs]. Pacific Medical Journal. 2007; 3: 55-7. [Russian]
  13. Pike CJ, Carroll JC, Rosario ER. Protective actions of sex steroid hormones in Alzheimer's disease. Front Neuroendocrinol. 2009 July; 30(2): 239-58. https://doi.org/10.1016/j.yfrne.2009.04.015. https://www.ncbi.nlm.nih.gov/pubmed/19427328. https://www.ncbi.nlm.nih.gov/pmc/articles/2728624
  14. Hammond J, Le Q, Goodyer C. Testosterone-mediated neuroprotection through the androgen receptor in human primary neurons. Journal of Neurochemistry. 2001; 77: 1319-26. https://doi.org/10.1046/j.1471-4159.2001.00345.x. https://www.ncbi.nlm.nih.gov/pubmed/11389183
  15. Foradori CD, Weiser MJ, Handa RJ. Non-genomic Actions of Androgens. Front Neuroendocrinol. 2008 May; 29(2): 169-81. https://doi.org/10.1016/j.yfrne.2007.10.005. https://www.ncbi.nlm.nih.gov/pubmed/18093638. https://www.ncbi.nlm.nih.gov/pmc/articles/2386261
  16. Sarkey S, Azcoitia I, Garcia-Segura LM. Classical androgen receptors in non-classical sites in the brain. Horm Behav. 2008 May; 53(5): 753-64. https://doi.org/10.1016/j.yhbeh.2008.02.015. https://www.ncbi.nlm.nih.gov/pubmed/18402960. https://www.ncbi.nlm.nih.gov/pmc/articles/2413135
  17. Asuthkar S, Demirkhanyan L, Sun X, Elustondo PA, Krishnan V, Baskaran P, et al. The TRPM8 Protein Is a Testosterone Receptor. J Biol Chem. 2015 Jan 30; 290(5): 2670-88. https://doi.org/10.1074/jbc.M114.610873. https://www.ncbi.nlm.nih.gov/pubmed/25480785. https://www.ncbi.nlm.nih.gov/pmc/articles/4316998
  18. Hussain R, Ghoumari AM, Bielecki B. The neural androgen receptor: a therapeutic target for myelin repair in chronic demyelination. Brain. 2013; 136: 132-46. https://doi.org/10.1093/brain/aws284. https://www.ncbi.nlm.nih.gov/pubmed/23365095. https://www.ncbi.nlm.nih.gov/pmc/articles/4572509
  19. Makiy EA, Rodinsky OG, Mozgunov OV Ephaptic excitation in the nervous system and conditions of its occurrence in pathological conditions. Medical perspectives. 2003; 8(1): 37-42.
  20. Evrard HC, Balthazart J. Aromatization of androgens into estrogens reduces response latency to a noxious thermal stimulus in male quail. Horm Behav. 2004; 45(3): 181-9. https://doi.org/10.1016/j.yhbeh.2003.09.014. https://www.ncbi.nlm.nih.gov/pubmed/15047013
  21. Evrard HC, Balthazart J. Rapid regulation of pain by estrogens synthesized in spinal dorsal horn neurons. J Neurosci. 2004; 24(33): 7225-9. https://doi.org/10.1523/JNEUROSCI.1638-04.2004. https://www.ncbi.nlm.nih.gov/pubmed/15317848. https://www.ncbi.nlm.nih.gov/pmc/articles/6729773
  22. Vanderhorst VG, Terasawa E, Ralston HJ, Vanderhorst VG. Estrogen receptor-α immunoreactive neurons in the brainstem and spinal cord of the female rhesus monkey: species-specific characteristics. Neuroscience. 2009; 158(2): 798-810. https://doi.org/10.1016/j.neuroscience.2008.10.017. https://www.ncbi.nlm.nih.gov/pubmed/18996446. https://www.ncbi.nlm.nih.gov/pmc/articles/4641676
  23. Zhong YQ, Li KC, Zhang X. Potentiation of excitatory transmission in substantia gelatinosa neurons of rat spinal cord by inhibition of estrogen receptor alpha. Mol Pain. 2010; 6: 92. https://doi.org/10.1186/1744-8069-6-92. https://www.ncbi.nlm.nih.gov/pubmed/21143988. https://www.ncbi.nlm.nih.gov/pmc/articles/3016347
  24. Lonchampt P, Chanelet J. Analyse unitaire des effets de stimulation des relais neuroniques primaires cutanes de la maelle de chat. C R Soc Biol. 1973; 6-7(167): 895-900.
  25. Szekely G, Kozaras B. Electron microscopic identification of postsynaptic dorsal root terminals: a possible substrate of dorsal root potentials in the frog spinal cord. Exp Brain Res. 1977; 29(3/4): 531-9.https://doi.org/10.1007/BF00236190. https://www.ncbi.nlm.nih.gov/pubmed/303179