Preserved neuron number in the hippocampus of aged rats with spatial learning deficits - PubMed (original) (raw)

Preserved neuron number in the hippocampus of aged rats with spatial learning deficits

P R Rapp et al. Proc Natl Acad Sci U S A. 1996.

Abstract

Hippocampal neuron loss is widely viewed as a hallmark of normal aging. Moreover, neuronal degeneration is thought to contribute directly to age-related deficits in learning and memory supported by the hippocampus. By taking advantage of improved methods for quantifying neuron number, the present study reports evidence challenging these long-standing concepts. The status of hippocampal-dependent spatial learning was evaluated in young and aged Long-Evans rats using the Morris water maze, and the total number of neurons in the principal cell layers of the dentate gyrus and hippocampus was quantified according to the optical fractionator technique. For each of the hippocampal fields, neuron number was preserved in the aged subjects as a group and in aged individuals with documented learning and memory deficits indicative of hippocampal dysfunction. The findings demonstrate that hippocampal neuronal degeneration is not an inevitable consequence of normal aging and that a loss of principal neurons in the hippocampus fails to account for age-related learning and memory impairment. The observed preservation of neuron number represents an essential foundation for identifying the neurobiological effects of hippocampal aging that account for cognitive decline.

PubMed Disclaimer

Similar articles

• Neuron number in the parahippocampal region is preserved in aged rats with spatial learning deficits.
  Rapp PR, Deroche PS, Mao Y, Burwell RD. Rapp PR, et al. Cereb Cortex. 2002 Nov;12(11):1171-9. doi: 10.1093/cercor/12.11.1171. Cereb Cortex. 2002. PMID: 12379605
• Circuit-specific alterations in hippocampal synaptophysin immunoreactivity predict spatial learning impairment in aged rats.
  Smith TD, Adams MM, Gallagher M, Morrison JH, Rapp PR. Smith TD, et al. J Neurosci. 2000 Sep 1;20(17):6587-93. doi: 10.1523/JNEUROSCI.20-17-06587.2000. J Neurosci. 2000. PMID: 10964964 Free PMC article.
• Improved spatial learning in aged rats by genetic activation of protein kinase C in small groups of hippocampal neurons.
  Zhang GR, Liu M, Cao H, Kong L, Wang X, O'Brien JA, Wu SC, Cook RG, Geller AI. Zhang GR, et al. Hippocampus. 2009 May;19(5):413-23. doi: 10.1002/hipo.20506. Hippocampus. 2009. PMID: 18942114 Free PMC article.
• Age-related biophysical alterations of hippocampal pyramidal neurons: implications for learning and memory.
  Wu WW, Oh MM, Disterhoft JF. Wu WW, et al. Ageing Res Rev. 2002 Apr;1(2):181-207. doi: 10.1016/s1568-1637(01)00009-5. Ageing Res Rev. 2002. PMID: 12039438 Review.
• Assessment of Second Messenger Function in the Hippocampus of Aged Rats with Cognitive Impairment.
  Nicolle MM, Zhang HY, Bizon JL. Nicolle MM, et al. In: Riddle DR, editor. Brain Aging: Models, Methods, and Mechanisms. Boca Raton (FL): CRC Press/Taylor & Francis; 2007. Chapter 9. In: Riddle DR, editor. Brain Aging: Models, Methods, and Mechanisms. Boca Raton (FL): CRC Press/Taylor & Francis; 2007. Chapter 9. PMID: 21204348 Free Books & Documents. Review.

Cited by

• Local amplification of glucocorticoids in the aging brain and impaired spatial memory.
  Yau JL, Seckl JR. Yau JL, et al. Front Aging Neurosci. 2012 Aug 29;4:24. doi: 10.3389/fnagi.2012.00024. eCollection 2012. Front Aging Neurosci. 2012. PMID: 22952463 Free PMC article.
• Neurogenesis within the adult hippocampus under physiological conditions and in depression.
  Dokter M, von Bohlen und Halbach O. Dokter M, et al. Neural Regen Res. 2012 Mar 5;7(7):552-9. doi: 10.3969/j.issn.1673-5374.2012.07.013. Neural Regen Res. 2012. PMID: 25745444 Free PMC article. Review.
• The ageing cortical synapse: hallmarks and implications for cognitive decline.
  Morrison JH, Baxter MG. Morrison JH, et al. Nat Rev Neurosci. 2012 Mar 7;13(4):240-50. doi: 10.1038/nrn3200. Nat Rev Neurosci. 2012. PMID: 22395804 Free PMC article. Review.
• Metabotropic glutamate receptor-mediated hippocampal phosphoinositide turnover is blunted in spatial learning-impaired aged rats.
  Nicolle MM, Colombo PJ, Gallagher M, McKinney M. Nicolle MM, et al. J Neurosci. 1999 Nov 1;19(21):9604-10. doi: 10.1523/JNEUROSCI.19-21-09604.1999. J Neurosci. 1999. PMID: 10531462 Free PMC article.
• Corticolimbic interactions associated with performance on a short-term memory task are modified by age.
  Della-Maggiore V, Sekuler AB, Grady CL, Bennett PJ, Sekuler R, McIntosh AR. Della-Maggiore V, et al. J Neurosci. 2000 Nov 15;20(22):8410-6. doi: 10.1523/JNEUROSCI.20-22-08410.2000. J Neurosci. 2000. PMID: 11069948 Free PMC article.

References

1. 1. Neurobiol Aging. 1993 Jul-Aug;14(4):287-93 - PubMed
2. 1. Prog Brain Res. 1992;93:365-81; discussion 382-3 - PubMed
3. 1. Ann N Y Acad Sci. 1994 Nov 30;746:308-21; discussion 321-6 - PubMed
4. 1. Ann N Y Acad Sci. 1994 Dec 15;747:382-406 - PubMed
5. 1. Science. 1995 Jul 14;269(5221):218-21 - PubMed

Publication types

MeSH terms

LinkOut - more resources

• Full Text Sources

  • Atypon
  • Europe PubMed Central
  • PubMed Central

• Other Literature Sources

  • The Lens - Patent Citations Database

• Medical

  • MedlinePlus Health Information