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Candemir M, Semiz S, Yonguc GN, Ozdemir MB, Abban-Mete G, Adiguzel E
Correspondence: Dr Esat Adiguzel, esatadiguzel@yahoo.com
ABSTRACT
Introduction The hippocampus is an important region of the brain that regulates cognitive and emotional functions. In this study, we examined the impact of perinatal administration of testosterone propionate (TP) on the number of pyramidal neurons in the CA1 and CA3 regions of the hippocampi of female rats.
Methods Five groups of rats were used in this study. Three groups of female rats were administered TP in either both the prenatal and the postnatal periods (Group 1), only the prenatal period (Group 2) or only the postnatal period (Group 3). The other two groups of rats included control females (Group 4) and control males (Group 5). The rats were sacrificed on postnatal Day 120 and their brains were analysed for hippocampal pyramidal neuron number using stereological methods.
Results Control male rats (Group 5; p = 0.043) and TP-treated female rats in Groups 1 (p = 0.012) and 2 (p = 0.037), but not Group 3 (p > 0.05), had a significantly higher number of pyramidal neurons than control female rats (Group 4). The rats in Group 1 had the highest number of pyramidal neurons among the female rats.
Conclusion Perinatal TP treatment has an augmenting effect on the number of pyramidal neurons in the hippocampi of female rats. We also found gender-based differences in the hippocampi of male and female rats, with a higher number of pyramidal neurons seen in male rats. Continuous TP administration during the prenatal and postnatal periods is more effective than administration only in the prenatal or postnatal period.
Keywords: androgens, female, perinatal, rat, stereology
Singapore Med J 2013; 54(6): 315-320; http://dx.doi.org/10.11622/smedj.2013124
REFERENCES
| 1. McCarthy MM, Konkle AT. When is a sex difference not a sex difference? Front Neuroendocrinol 2005; 26:85-102. http://dx.doi.org/10.1016/j.yfrne.2005.06.001 |
||||
| 2. Hrabovszky Z, Hutson JM. Androgen imprinting of the brain in animal models and humans with intersex disorders: review and recommendations. J Urol 2002; 168:2142-8. http://dx.doi.org/10.1016/S0022-5347(05)64338-8 |
||||
| 3. Isgor C, Sengelaub DR. Prenatal gonadal steroids affect adult spatial behavior, CA1 and CA3 pyramidal cell morphology in rats. Horm Behav 1998; 34:183-98. http://dx.doi.org/10.1006/hbeh.1998.1477 |
||||
| 4. Wolf CJ, Hotchkiss A, Ostby JS, LeBlanc GA, Gray LE Jr. Effects of prenatal testosterone propionate on the sexual development of male and female rats: a dose-response study. Toxicol Sci 2002; 65:71-86. http://dx.doi.org/10.1093/toxsci/65.1.71 |
||||
| 5. Papez JW. Visceral brain, its components parts and their connections. J Nerv Ment Dis 1958; 126:40-56. http://dx.doi.org/10.1097/00005053-195801000-00005 |
||||
| 6. Woodson JC, Balleine BW, Gorski RA. Sexual experience interacts with steroid exposure to shape the partner preferences of rats. Horm Behav 2002; 42:148-57. http://dx.doi.org/10.1006/hbeh.2002.1816 |
||||
| 7. Isgor C, Sengelaub DR. Effects of neonatal gonadal steroids on adult CA3 pyramidal neuron dendritic morphology and spatial memory in rats. J Neurobiol 2003; 55:179-90. http://dx.doi.org/10.1002/neu.10200 |
||||
| 8. Zhang JM, Konkle AT, Zup SL, McCarthy MM. Impact of sex and hormones on new cells in the developing rat hippocampus: a novel source of sex dimorphism? Eur J Neurosci 2008; 27:791-800. http://dx.doi.org/10.1111/j.1460-9568.2008.06073.x |
||||
| 9. Xiao L, Jordan CL. Sex differences, laterality, and hormonal regulation of androgen receptor immunoreactivity in rat hippocampus. Horm Behav 2002; 42:327-36. http://dx.doi.org/10.1006/hbeh.2002.1822 |
||||
| 10.West MJ, Slomianka L, Gundersen HJ. Unbiased stereological estimation of the total number of neurons in the subdivisions of the rat hippocampus using the optical fractionator. Anat Rec 1991; 231:482-97. http://dx.doi.org/10.1002/ar.1092310411 |
||||
| 11. Gundersen HJ, Bagger P, Bendtsen TF, et al. The new stereological tools: disector, fractionator, nucleator and point sampled intercepts and their use in pathological research and diagnosis. APMIS 1988; 96:857-81. http://dx.doi.org/10.1111/j.1699-0463.1988.tb00954.x |
||||
| 12. Paxinos G, Watson C. The Rat Brain in Stereotaxic Coordinates. 6th ed. USA: Academic Press, Elsevier, 2007. | ||||
| 13. Paxinos G. Hippocampal formation. In: Paxinos G, ed. The Rat Nervous System. 3rd ed. USA: Academic Press, Elsevier, 2004: 637-87. | ||||
| 14. Hosseini-Sharifabad M, Nyengaard JR. Design-based estimation of neuronal number and individual neuronal volume in the rat hippocampus. J Neurosci Methods 2007; 162:206-14. http://dx.doi.org/10.1016/j.jneumeth.2007.01.009 |
||||
| 15. Demissie M, Lazic M, Foecking EM, et al. Transient prenatal androgen exposure produces metabolic syndrome in adult female rats. Am J Physiol Endocrinol Metab 2008; 295:262-8. http://dx.doi.org/10.1152/ajpendo.90208.2008 |
||||
| 16. Hilton GD, Nu-ez JL, McCarthy MM. Sex differences in response to kainic acid and estradiol in the hippocampus of newborn rats. Neuroscience 2003; 116:383-91. http://dx.doi.org/10.1016/S0306-4522(02)00716-9 |
||||
| 17. Madeira MD, Sousa N, Lima-Andrade MT, et al. Selective vulnerability of the hippocampal pyramidal neurons to hypothyroidism in male and female rats. J Comp Neurol 1992; 322:501-18. http://dx.doi.org/10.1002/cne.903220405 |
||||
| 18. Wimer RE, Wimer C. Three sex dimorphisms in the granule cell layer of the hippocampus in house mice. Brain Res 1985; 328:105-9. http://dx.doi.org/10.1016/0006-8993(85)91328-9 |
||||
| 19. Guillery RW, Herrup K. Quantification without pontification: choosing a method for counting objects in sectioned tissues. J Comp Neurol 1997; 386:2-7. http://dx.doi.org/10.1002/(SICI)1096-9861(19970915)386:1<2::AID-CNE2>3.0.CO;2-6 |
||||