Stereological analysis of cornu ammonis in prenatally stressed rats: a heuristic neurodevelopmental model of schizophrenia

Document Type: Original Article


1 Department of Biology and Anatomical Sciences, Shahid Sadoughi University of Medical Sciences, Yazd, Iran

2 Department of Anatomical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran


Objective(s):The hippocampus has been implicated in pathophysiology of schizophrenia. Prenatal stress is a contributing risk factor for a wide variety of neuropsychiatric diseases including schizophrenia. This study examined long-term effects of prenatal restraint stress on the stereological parameters in the Cornu Ammonis (CA) of adult male rats as an animal model of schizophrenia.
Materials and Methods:Wistar pregnant dams in experimental group were stressed in a cylindrical Plexiglas restrainer daily for 1 hr during last week of gestation. Controls remained in the animal room and were exposed only to normal animal room conditions. At 2 months of age, the volume of the pyramidal cell layer of the CA, the numerical density and the somal volume of the respective neurons were assessed in the male offspring generated from stressed and control pregnancies. Cavalieri's principle, physical disector and nucleator were applied for stereological analyses.
Results:This study showed that prenatal stress significantly decreased the volume of CA3 pyramidal cell layer and the individual somal volume of CA3 pyramidal neurons. However, there were no markedly differences in the numerical density, total number of CA3 pyramidal neurons and stereological parameters in CA1 of prenatally stressed and control animals.
Conclusion: These data indicate that prenatal stress exposure induced neuronal changes in the CA3 subfield of hippocampus which are similar to what is observed in schizophrenia.


 1. Brunton PJ, Russell JA. Prenatal social stress in the rat programmes neuroendocrine and behavioural responses to stress in the adult offspring: sex specific effects. J Neuroendocrinol 2010; 22:258-271.

2. Weinstock M. The long-term behavioural consequences of prenatal stress. Neurosci Biobehav Rev 2008; 32:1073-1086.

3. Markham JA, Taylor AR, Taylor SB, Bell DB, Koenig JI. Characterization of the cognitive impairments induced by prenatal exposure to stress in the rat. Front Behav Neurosci 2010; 254:173.

4. Lee PR., Brady DL, Shapiro RA, Dorsa DM, Koenig JI. Prenatal stress generates deficits in rat social behavior: Reversal by oxytocin. Brain Res 2007; 1156:152-167.

5. Koenig JI, Elmer GI, Shepard PD, Lee PR, Mayo C, Joy B,et al. Prenatal exposure to a repeated variable stress paradigm elicits behavioral and neuroendocrinological changes in the adult offspring: potential relevance to schizophrenia. Behav Brain Res 2005; 156:251-261.

6. Kinnunen AK, Koenig JI, Bilbe G. Repeated variable prenatal stress alters pre- and postsynaptic gene expression in the rat frontal pole. J Neurochem 2003; 86:736-748.

7. Khashan AS, Abel KM, McNamee R, Pedersen MG, Webb RT, Baker PN,et al. Higher risk of offspring schizophrenia following antenatal maternal exposure to severe adverse life events. Arch Gen Psychiatry 2008; 65:146-152.

8. Koenig JI, Kirkpatrick B, Lee P. Glucocorticoid hormones and early brain development in schizophrenia. Neuropsychopharmacology 2002; 27:309-318.

9. Yaka R, Salomon S, Matzner H, Weinstock M. Effect of varied gestational stress on acquisition of spatial memory, hippocampal LTP and synaptic proteins in juvenile male rats. Behav Brain Res 2007; 179:126-132.

10. Boyer P, Phillips JL, Rousseau FL, Ilivitsky S. Hippocampal abnormalities and memory deficits: new evidence of a strong pathophysiological link in schizophrenia. Brain Res Rev 2007; 54: 92-112.

11. Wu J, Song TB, Li YJ, He KS, Ge L, Wang LR. Prenatal restraint stress impairs learning and memory and hippocampal PKCbeta1 expression and translocation in offspring rats. Brain Res 2007; 1141:205-213.

12. Mueller, BR, Bale TL. Early prenatal stress impact on coping strategies and learning performance is sex dependent. Physiol Behav 2007; 91:55-65.

13. Stefanis N, Frangou S, Yakeley J, Sharma T, O’Connell P, Morgan K,et al. Hippocampal volume reduction in schizophrenia: effects of genetic risk and pregnancy and birth complications. Biol Psychiatry 1999; 46:697-702.

14. Nelson MD, Saykin AJ, Flashman LA, Riordan HJ. Hippocampal volume reduction in schizophrenia as assessed by magnetic resonance imaging: a meta analytic study. Arch Gen Psychiatry 1998; 55:433-440.

15. Highley JR, Walker MA, Mc Donald B, Crow TJ, Esiri MM. Size of hippocampal pyramidal neurons in schizophrenia. Br J Psychiatry 2003; 183: 414-417.

16. Harrison PJ. The hippocampus in schizophrenia: a review of the neuropathological evidence and its pathophysiological implications. Psychopharmaco-logy (Berl) 2004; 174:151-62.

17. Nopoulos P, Flaum M, Andreasen NC. Sex differences in brain morphology in schizophrenia Am J Psychiatry 1997; 154:1637-1619.

18. Hosseini-sharifabad M, Sabahi AR. Prenatal stress induces impairment of memory and reduction in the volume of hippocampus in rat. J Isfahan Med School 2006; 75:67-72.

19. Hosseini-sharifabad M, Esfandiari E, Hossein-sharifabad A. The effect of prenatal exposure to restraint stress on hippocampal granule neurons of adult rat offspring. Iran J Basic Med Sci 2012; 15:1060-1067.

20. Lemaire V, koehl M, Moal Le M, Abrous DN. Prenatal stress produces learning deficits associated with an inhibition of neurogenesis in the hippocampus. Proc Natl Acad Sci 2000; 97:11032-11037.

21. Zhu Z, Li X, Chen W, Zhao Y, Li H, Qing C,et al. Prenatal stress causes gender-dependent neuronal loss and oxidative stress in rat hippocampus. J Neurosci Res 2004; 78:837-844.

22. Schmitz C, Bultmann E, Gube M, Korr H. Neuron loss in the mouse hippocampus following prenatal injection of triated thymidine or saline. Int J Dev Neurosci 1999; 17:185-190.

23. Hosseini-sharifabad M, Nyengaard JR. Design-based estimation of neuronal number and individual neuronal volume in the rat hippocampus. J Neurosci Meth 2007; 162:206-214.

24. Gokhale AM, Evans RA, Mackes JL, Mouton PR. Design-based estimation of surface area in thick tissue sections of arbitrary orientation using virtual cycloids. J Microsc 2004; 216: 25-31.

25. Schmitz C, Hof PR. Design-based stereology in neuroscience. Neuroscience 2005; 30:813-831.

26. Chapman RH and Stern J. Maternal stress and pituitary-adrenal manipulations during pregnancy in rats: effects on morphology and sexual behavior of male offspring. J Comp Physiol Psychol 1978; 92:1074-1083.

27. Amaral D, Witter M. Hippocampal formation. In: Paxinos G. Editor. The Rat Nervous System. San Diego: Academic Press; 1995.p. 443-493.

28. Gundersen HJG, Bendtsen TF, Korbo L, Marcussen N, Møller A, Nielsen K,et al. Some new, simple and efficient stereological methods and their use in pathological research and diagnosis. Acta Pathol Microbiol Immunol Scand 1988; 96:379-394.

29. Miki T, Satriotomo I, Li HP, Matsumoto Y, Gu H, Yokoyama T,et al. Application of the physical disector to the central nervous system: estimation of the total number of neurons in subdivisions of the rat hippocampus. Anat Sci Int 2005; 80:153-162.

30. Gundersen HJG, Jensen EB, Kieu K, Nielsen J. The efficiency of systematic sampling in Hosseini-sharifabad and Sabahi Prenatal stress and the structure of cornu ammonis stereology– reconsidered. J Microsc 1999; 193:199-211.

31. Gundersen HJG, Jensen EB. Stereological estimation of the volume-weighted mean volume of arbitrary particles observed on random sections. J Microsc 1985; 138:127-142.

32. Hosseini-sharifabad M, Hadinedoushan H. Prenatal stress induces learning deficits and is associated with a decrease in granules and CA3 cell dendritic tree size in rat hippocampus. Anat Sci Int 2007; 82:211-217.

33. Da Costa NM, Fürsinger D, Martin KA. The synaptic organization of the claustral projection to the cat's visual cortex. J Neurosci 2010; 30:13166-13170.

34. Hayes TL, Lewis DA. Hemispheric differences in layer III pyramidal neurons of the anterior language areas. Arch Neurol 1993; 50:501-505.

35. Jacobs B, Driscoll L, Schall M. Life-span dendritic and spine changes in areas 10 and 18 of human cortex: A quantitative Golgi study. J Comp Neurol 1997; 386:661-680.

36. Bussière T, Gold G, Kovari E, Giannakopoulos P, Bouras C, Perl DP,et al. Stereologic analysis of neurofibrillary tangle formation in prefrontal cortex area 9 in aging and Alzheimer’s disease. Neuroscience 2003; 117:577-592.

37. Insausti AM, Gaztelu JM, Gonzalo LM, Romero-Vives M, Barrenechea C, Felipo V,et al. Diet induced hyperammonemia decreases neuronal nuclear size in rat entorhinal cortex. Neurosci Lett 1997; 231:179-181.

38. Arnold SE, Franz BR, Gur RC, Gur RE, Shapiro RM, Moberg PJ,et al. Smaller neuron size in schizophrenia in hippocampal subfields that mediate cortical-hippocampal interactions. Am J Psychiatry 1995; 152:738-748.

39. Ulupinar E, Yucel F, Ortug G. The effects of prenatal stress on the Purkinje cell neurogenesis. Neurotoxicol Teratol 2006; 28 :86-94.

40. Barbazanges A, Piazza PV, Le Moal M, Maccari S.Maternal glucocorticoid secretion mediates long-term effects of prenatal stress. J Neurosci 1996; 16:3943-1939.

41. Darnaudéry M, Maccari S. Epigenetic programming of the stress response in male and female rats by prenatal restraint stress. Brain Res Rev 2008; 57:571-855.

42. Zarrow MO, Philpott J, Deneberg V. Passage of 14C-4-corticosterone from the rat mother to the fetus and neonate. Nature 1970; 226:1058-1059.

43. Sapolsky RM. Glucocorticoids and hippocampal atrophy in neuropsychiatric Disorders. Arch Gen Psychiatry 2000; 57:925-935.

44. McEwen BS, Magariños AM, Reagan LP. Studies of hormone action in the hippocampal formation: possible relevance to depression and diabetes. J Psychosom Res 2002; 53:883-890.

45. Pryce CR, Aubert Y, Maier C, Pearce PC, Fuchs E. The developmental impact of prenatal stress, prenatal dexamethasone and postnatal social stress on physiology, behaviour and neuroanatomy of primate offspring: studies in rhesus macaque and common marmoset. Psychopharmacology (Berl) 2011; 214:33-53.

46. Heckers S, Heinsen H, Geiger B, Beckmann H. Hippocampal neuron number in schizophrenia: a stereological study. Arch Gen Psychiatry 1991; 48:1002-1008.

47. Kovelman JA, Scheibel AB. A neurohistological correlate of schizophrenia. Biol Psychiatry 1984; 19: 601-621.

48. Zaidel DW, Esiri MM, Harrison PJ. Size, shape, and orientation of neurons in the left and right hippocampus: nvestigation of normal asymmetries and alterations in schizophrenia. Am J Psychiatry 1997; 154:812-818.

49. Benes FM, Sorensen I, Bird ED. Reduced neuronal size in posterior hippocampus of schizophrenic patients. Schizophr Bull 1991; 17:597-608.