Document Type : Original Research


Dept. of Anatomical Scienesc, North Khorasan University of Medical Sciences, Bojnurd, Iran


Background and Objectives: Studies have documented the morhplogical, neurochemical and functional difference between the dorsal and ventral zones of hippocampus. The aim of this study was to assess the effects of chronic diabetes mellitus type1 on ventral and dorsal zones of hippocampus.
Methods: Experimental diabetes was induced by stereptozotocin at a dose of 60 mg/kg. At the end of 8 weeks the brains were removed and stained by cresyl violet. The number of dark neurons in CA1 and CA3 regions of dorsal and ventral zones of hippocampus was counted by modified stereological method.
Results: The number of dead neurons in CA3 ventral showed significant level of difference (P<0.05) in comparison to CA3 dorsal. The number of dead neurons in CA1 ventral and CA1 dorsal showed also significant difference (P<0.05)
Conclusion: The results of our study indicative of more vulnerability of ventral zones the dorsal zone of hippocampus to diabetes mellitus type 1.


  1. Levin ED, Christopher NC, Weaver T, Moore J, Brucato F. Ventral hippocampal ibotenic acid lesions block chronic nicotine-induced spatial working memory improvement in rats. Brain Res Cogn Brain Res 1999 ;7(3):405-10.
  2. Fanselow MS, Dong HW. Are the dorsal and ventral hippocampus functionally distinct structures. Neuron 2010;65(1):7-19.
  3. Moser M, Moser E, Forrest E, Andersen P, Morris RG. Spatial learning with the mini slab in the dorsal hippocampus. Proc Natl Acad Sci 1995;92:9697–701.
  4. Mooradian AD. Central nervous system complications of diabetes mellitusaPerspective from blood brain barrier. Brain Res Rev 1997;23:210-8.
  5. Ahmadpour sh, Sadegi Y, sheibanifar M, Haghir H. Neuronal death in dentate gyrus and CA3 in diabetic rats: effects of insulin and ascorbic acid. J Hormozan Med Sci 2010;13(4):234-45.
  6. Magariños AM, McEwen BS. Experimental diabetes in rats causes hippocampal dendritic and synaptic reorganization and increased glucocorticoid reactivity to stress. Proc Natl Acad Sci USA 2000;97(20):11056.
  7. Ahmadpour sh, Sadegi Y,Haghir H. Streptozotocin-induced hyperglycemia produces dark neuron in CA3 region of hippocampus in rats. AJMS 2010;1(2):11-5.
  8. Ahmadpour sh, Haghir H. Diabetes mellitus type1 induces dark neuron formation in the dentate gyrus: A study by gallyas' method and Transmission Electron Microscopy. Rom J Morphol Embryol 2011;52(2):575–9.
  9. Li ZG, Zhang W, Grunberger G, Sima AA. Hippocampal neuronal apoptosis in type 1 diabetes. Brain Res 2002;946 (2):221-31.
  10. Eichenbaum, H, Dudchenko P, Wood E, Shapiro M, Tanila H. The hippocampus, memory, and place cells: is it spatial memory or a memory space? Neuron 1999;23(2):209-26.
  11. Fuster-Matanzo A, Llorens-Martín M, de Barreda EG, Ávila J, Hernández F. Different Susceptibility to Neurodegeneration of Dorsal and Ventral Hippocampal Dentate Gyrus: A Study with Transgenic Mice Overexpressing GSK3b. PLoS ONE 2011; 6 (11):e27262.
  12. Fanselow MS, Dong HW. Are The Dorsal and Ventral Hippocampus functionally distinct structures?Neuron 2010;14:65(1):7-19.
  13. Hock BJ, Bunsey MD.Differential Effects of Dorsal and Ventral Hippocampal Lesions.The J Neurosci 19981;18(17):7027–32.
  14. Bunsey MD, Eichenbaum H. Conservation of hippocampal memory function in rats and humans. Nature 1996;379:255–7.
  15. Gluck MA, Myers CE. Representation and association in memory: a neurocomputational view of hippocampal function. Curr Direct Psychol Sci 1995;4:23–9.
  16. Leonardo ED, Richardson-Jones JW, Sibille E, Kottman A, Hen R. Molecular heterogeneity along the dorsal-ventral axis of the murine hippocampal CA1 field: a microarray analysis of gene expression. Neuroscience 2006;137(1):177-86.
  17. Pandis C, Sotiriou E, Kouvaras E, Asprodini E, Papatheodoropoulos C, Angelatou F. Differential expression of NMDA and AMPA receptor subunits in rat dorsal and ventral hippocampus. Neuroscience 2006;140(1):163-75.
  18. Spruston N, Jonas P, Sakmann B. Dendritic glutamate receptor channels in rat hippocampal CA3 and CA1 pyramidal neurons. J Physiol (Lond) 1995;482:325–52.
  19. Kherani ZS, Auer RN. Pharmacologic analysis of the mechanism of dark neuron production in cerebral cortex. Acta Neuropathol 2008;116(4):447-52.
  20. Brooks JM, Pershing ML, Thomsen MS, Mikkelsen JD, Sarter M, Bruno JP. Transient inactivation of the neonatal ventral hippocampus impairs attentional set-shifting behavior: reversal with an α7 nicotinic agonist. Neuropsychopharmacology 2012;37(11):2476-86.
  21. Bast T· Zhang WN· Feldon J. The ventral hippocampus and fear conditioning in rats Different anterograde amnesias of fear after tetrodotoxin inactivation and infusion of the GABAA agonist muscimol. Exp Brain Res 2001;139:39–52.