Stereological analysis of sciatic nerve in chickens following neonatal pinealectomy: an experimental study^[*]

Abstract

Background Although the injury to the peripheral nervous system is a common clinical problem, understanding of the role of melatonin in nerve degeneration and regeneration is incomplete.

Methods The current study investigated the effects of neonatal pinealectomy on the sciatic nerve microarchitecture in the chicken. The chickens were divided into two equal groups: unpinealectomized controls and pinealectomized chickens. At the end of the study, biochemical examination of 10 sciatic nerve samples from both groups was performed and a quantitative stereological evaluation of 10 animals in each group was performed. The results were compared using Mann-Whitney test.

Results In this study, the results of axon number and thickness of the myelin sheath of a nerve fiber in newly hatched pinealectomy group were higher than those in control group. Similarly, surgical pinealectomy group had significantly larger axonal cross-sectional area than the control group (p < 0.05). In addition, the average hydroxyproline content of the nerve tissue in neonatal pinealectomy group was higher than those found in control group. Our results suggest that melatonin may play a role on the morphologic features of the peripheral nerve tissue and that melatonin deficiency might be a pathophysiological mechanism in some degenerative diseases of peripheral nerves. The changes demonstrated by quantitative morphometric methods and biochemical analysis has been interpreted as a reflection of the effects of melatonin upon nerve tissue.

Conclusion In the light of these results from present animal study, changes in sciatic nerve morphometry may be indicative of neuroprotective feature of melatonin, but this suggestion need to be validated in the human setting.

^*This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

• References

• 1 Goodrum JF, Bouldin TW. The cell biology of myelin degeneration and regeneration in the peripheral nervous system. J Neuropathol Exp Neurol 1996; 55: 943-953 10.1097/00005072-199609000-00001 8800090
• 2 Payne Jr SH. Nerve repair and grafting in the upper extremity. J South Orthop Assoc 2001; 10: 173-189 12132829
• 3 Xu Q-G, Zochodne DW. Ischemia and failed regeneration in chronic experimental neuromas. Brain Res 2002; 946: 24-30 10.1016/S0006-8993(02)02820-2 12133591
• 4 Zochodne DW. The microenvironment of injured and regenerating peripheral nerves. Muscle Nerve Supplement 2000; 9: S33-38 10.1002/1097-4598(2000)999:9<::AID-MUS7>3.0.CO;2-F 11135282
• 5 Romero FJ, Monsalve E, Hermenegildoc-Puertas FJ, Puertas FJ, Higueras V, Nies E, Segura-Aguilar J, Roma J. Oxygen toxicity in the nervous tissue. Comparison of the antioxidant defense of rat brain and sciatic nerve. Neurochem Res 1991; 16: 157-161 10.1007/BF00965704 1908956
• 6 Kihara M, Kamijo M, Nakasaka Y, Mitsui Y, Takahashi M, Schmelzer JD. A small dose of the immunosupressive agent FK506 (tacrolimus) protects peripheral nerve from ischemic fiber degeneration. Muscle Nerve 2001; 24: 1601-1606 10.1002/mus.1194 11745968
• 7 Mitsui Y, Schmelzer JD, Zollman PJ, Mitsui M, Tritschler HJ, Low PA. Alpha-lipoic acid provides neuroprotection from ischemia-reperfusion injury after peripheral nerve. J Neurol Sci 1999; 163: 11-16 10.1016/S0022-510X(99)00017-9 10223404
• 8 Lerner AB, Case JD, Mori W, Wright MR. Melatonin in peripheral nerve. Nature 1959; 183: 1821 10.1038/1831821a0 14415934
• 9 Kilic E, Hermann DM, Isenmann S, Bahr M. Effects of pinealectomy and melatonin on the retrograde degeneration of retinal ganglion cells in a novel model of intraorbital optic nerve transection in mice. J Pineal Res 2002; 32: 106-111 10.1034/j.1600-079x.2002.1823.x 12071467
• 10 Kondoh T, Uneyama H, Nishino H, Torii K. Melatonin reduces cerebral edema formation caused by transient forebrain ischemia in rats. Life Sci 2002; 72: 583-590 10.1016/S0024-3205(02)02256-7 12467899
• 11 Krause DN, Siuciak JA, Dubocovich ML. Unilateral optic nerve transection decreases 2-[1251]-iodomelatonin binding in retinorerecipient areas and visual pathways of chick brain. Brain Res 1994; 654: 63-74 10.1016/0006-8993(94)91571-7 7982099
• 12 Pei Z, Pang SF, Cheung RTF. Pretreatment with melatonin reduces volume of cerebral infarction in a rat middle cerebral artery occlusion stroke model. J Pineal Res 2002; 32: 168-172 10.1034/j.1600-079x.2002.1o847.x 12074100
• 13 Rogerio F, de Souza Queiroz L, Teixeira SA, Oliveira AL, de Nucci G, Langone F. Neuroprotective action of melatonin on neonatal rat motoneurons after sciatic nerve transection. Brain Res 2002; 926: 33-41 10.1016/S0006-8993(01)03286-3 11814404
• 14 Sayan H, Ozcakmak VH, Ozen OA, Coskun O, Arslan SO, Sezen SC, Aktas RG. Beneficial effects of melatonin on reperfusion injury in rat sciatic nerve. J Pineal Res 2004; 37: 143-148 15357657
• 15 Andrabi SA, Sayeed I, Siemen D, Wolf G, Horn TF. Direct inhibition of the mitochondrial permeability transition pore: a possible mechanism responsible for anti-apoptotic effects of melatonin. FASEB 2004; 18: 869-871
• 16 Turgut M, Yenisey C, Uysal A, Bozkurt M, Yurtseven ME. The effects of pineal gland transplantation on the production of spinal deformity and serum melatonin level following pinealectomy in the chicken. Eur Spine J 2003; 12: 487-494 10.1007/s00586-003-0528-9 12687443
• 17 Hrouda G. A method to remove epoxy resins from biological material. Mikroskopie 1985; 42: 315-317
• 18 Iwadare T, Harada E, Yoshino S, Arai T. A solution for removal of resin from epoxy sections. Stain Technol 1990; 65: 205-209 1699307
• 19 Robinson G, Gray T. Electron microscopy 2: Practical procedures. In: Bancroft JD, Stevens A. Theory and Practice of Histological Techniques. Churchill Livingstone; New York: 1996: 585-626
• 20 Larsen JO. Stereology of nerve cross sections. J Neurosci Methods 1998; 85: 107-118 10.1016/S0165-0270(98)00129-0 9874147
• 21 Geuna S, Tos P, Guglielmone R, Battiston B, Giacobini-Robecchi MG. Methodological issues in size estimation of myelinated nerve fibers in peripheral nerves. Anat Embryol 2001; 204: 1-10 10.1007/s004290100188 11506429
• 22 Nukada H, Powell HC, Myers RR. Spatial distribution of nerve injury after occlusion of individual major vessels in rat sciatic nerve. J Neuropathol Exp Neurol 1993; 52: 452-459 10.1097/00005072-199309000-00003 8360699
• 23 Gundersen HJG. Notes on the estimation of the numerical density of arbitrary particles: The edge effect. J Microsc 1977; 111: 219-223
• 24 Gundersen HJG. Stereology of arbitrary particles. A review of unbiased number and size estimators and the presentation of some new ones, in memory of William R Thompson. J Microsc 1986; 143: 3-45 3761363
• 25 Keskin M, Akbas H, Uysal AO, Canan S, Ayyildiz M, Agar E, Kaplan S. Enhancement of nerve regeneration and orientation across a gap by using the nerve graft within the nerve vein conduit graft: A functional, stereological, and electrophysiological study. Plast Reconstr Surg 2004; 113: 1372-1379 10.1097/01.PRS.0000111596.61137.A1 15060349
• 26 Schmitz C. Variation of fractionator estimates and its prediction. Anat Embryol 1998; 198: 371-397 10.1007/s004290050191 9801058
• 27 Schmitz C, Hof PR. Recommendations for straightforward and rigorous methods of counting neurons based on a computer simulation approach. J Chem Neuroanat 2000; 20: 93-114 10.1016/S0891-0618(00)00066-1 11074347
• 28 West MJ, Slomianka L, Gundersen HJG. Unbiased stereological estimation of the total number of neurons in the subdivisions of the rat hippocampus using the optical fractionator. Anat Rec 1991; 231: 482-497 10.1002/ar.1092310411 1793176
• 29 Reddy GK, Enwemeka CS. A simplified method for the analysis of hydroxyproline in biological tissues. Clin Biochem 1996; 29: 225-229 10.1016/0009-9120(96)00003-6 8740508
• 30 Edward CA, O’Brien WD. Modified assay for determination of hydroxyproline in a tissue hydrolyzate. Clin Chim Acta 1980; 104: 161-167 10.1016/0009-8981(80)90192-8 7389130
• 31 Neuman RE, Logan MA. The determination of collagen and elastin in tissue. J Biol Chem 1950; 186: 549 14794650
• 32 Battiston B, Tos P, Geuna S, Giacobini-Robecchi MG, Guglielmone R. Nerve repair by means of vein filled with muscle grafts. II. Morphological analysis of regeneration. Microsurgery 2000; 20: 37-41 10.1002/(SICI)1098-2752(2000)20:1<37::AID-MICR7>3.0.CO;2-5 10617880
• 33 Turgut M, Uyanıkgil Y, Baka M, Tunc AT, Yavasoglu A, Yurtseven ME, Kaplan S. Pinealectomy exaggerates and melatonin treatment suppresses neuroma formation of transected sciatic nerve in rats: gross morphological, histological and stereological analysis. J Pineal Res 2005; 38: 284-291 10.1111/j.1600-079X.2004.00205.x 15813906
• 34 Turgut M, Uysal A, Pehlivan M, Oktem G, Yurtseven ME. Assessment of effects of pinealectomy and exogenous melatonin administration on rat sciatic nerve suture repair: an electrophysiological, electron microscopic, and immunohistochemical study. Acta Neurochir (Wien) 2005; 147: 67-77 10.1007/s00701-004-0426-x 15565477
• 35 Yu W, Kauppila T, Hultenby K, Persson JKE, Xu XJ, Wiesenfeld-Hallin Z. Photochemically-induced ischemic injury of the rat sciatic nerve: a light- and electron microscopic study. J Peripher Nerv Syst 2000; 5: 209-217 10.1046/j.1529-8027.2000.00024.x 11151981
• 36 Verdu E, Ceballos D, Vilches JJ, Navarro X. Influence of aging on peripheral nerve function and regeneration. J Peripher Nerv Syst 2000; 5: 191-208 10.1046/j.1529-8027.2000.00026.x 11151980
• 37 Gomez N, Cuadras J, Buti M, Navarro X. Histological assessment of sciatic nerve regeneration following resection and graft or tube repair in the mouse. Restor Neurol and Neurosci 1996; 10: 187-96
• 38 Lundborg G. Nerve injury and repair-a challenge to the plastic brain. J Peripher Nerv Syst 2003; 8: 209-226 10.1111/j.1085-9489.2003.03027.x 14641646
• 39 Cheung RTF. The utility of melatonin in reducing cerebral damage resulting from ischemia and reperfusion. J Pineal Res 2003; 34: 153-160 10.1034/j.1600-079X.2003.00034.x 12614473
• 40 Cuzzocrea S, Costantino G, Gitto E, Mazzon E, Fulia F, Serraino I, Cordaro S, Barberi I, De Sarro A, Caputi AP. Protective effects of melatonin in ischemic brain injury. J Pineal Res 2000; 29: 217-227 10.1034/j.1600-0633.2002.290404.x 11068944