Postpubertal decrease in hippocampal dendritic spines of female rats

Murat Yildirim, Oni M. Mapp, William G.M. Janssen, Weiling Yin, John Morrison, Andrea C. Gore

Research output: Contribution to journalArticle

30 Citations (Scopus)

Abstract

Hippocampal dendritic spine and synapse numbers in female rats vary across the estrous cycle and following experimental manipulation of hormone levels in adulthood. Based on behavioral studies demonstrating that learning patterns are altered following puberty, we hypothesized that dendritic spine number in rat hippocampal CA1 region would change postpubertally. Female Sprague-Dawley rats were divided into prepubertal (postnatal day (P) 22), peripubertal (P35) and postpubertal (P49) groups, with the progression of puberty evaluated by vaginal opening, and estrous cyclicity subsequently assessed by daily vaginal smears. Spinophilin immunoreactivity in dendritic spines was used as an index of spinogenesis in area CA1 stratum radiatum (CA1sr) of hippocampus. First, electron microscopy analyses confirmed the presence of spinophilin specifically in dendritic spines of CA1sr, supporting spinophilin as a reliable marker of hippocampal spines in young female rats. Second, stereologic analysis was performed to assess the total number of spinophilin-immunoreactive puncta (i.e. spines) and CA1sr volume in developing rats. Our results indicated that the number of spinophilin-immunoreactive spines in CA1sr was decreased 46% in the postpubertal group compared to the two younger groups, whereas the volume of the hippocampus underwent an overall increase during this same developmental time frame. Third, to determine a potential role of estradiol in this process, an additional group of rats was ovariectomized (OVX) prepubertally at P22, then treated with estradiol or vehicle at P35, and spinophilin quantified as above in rats perfused on P49. No difference in spinophilin puncta number was found in OVX rats between the two hormone groups, suggesting that this developmental decrease is independent of peripheral estradiol. These changes in spine density coincident with puberty may be related to altered hippocampal plasticity and synaptic consolidation at this phase of maturity.

Original languageEnglish (US)
Pages (from-to)339-348
Number of pages10
JournalExperimental Neurology
Volume210
Issue number2
DOIs
StatePublished - Apr 1 2008
Externally publishedYes

Fingerprint

Dendritic Spines
Hippocampal CA1 Region
Spine
Puberty
Estradiol
Hippocampus
Hormones
Vaginal Smears
Neuronal Plasticity
Group Processes
Estrous Cycle
Periodicity
neurabin
Synapses
Sprague Dawley Rats
Electron Microscopy
Learning

Keywords

  • CA1
  • Dendritic spine
  • Estrogen
  • Hippocampus
  • Puberty
  • Spinogenesis
  • Spinophilin
  • Synaptic plasticity

ASJC Scopus subject areas

  • Neurology
  • Developmental Neuroscience

Cite this

Postpubertal decrease in hippocampal dendritic spines of female rats. / Yildirim, Murat; Mapp, Oni M.; Janssen, William G.M.; Yin, Weiling; Morrison, John; Gore, Andrea C.

In: Experimental Neurology, Vol. 210, No. 2, 01.04.2008, p. 339-348.

Research output: Contribution to journalArticle

Yildirim, Murat ; Mapp, Oni M. ; Janssen, William G.M. ; Yin, Weiling ; Morrison, John ; Gore, Andrea C. / Postpubertal decrease in hippocampal dendritic spines of female rats. In: Experimental Neurology. 2008 ; Vol. 210, No. 2. pp. 339-348.
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