Elsevier

Brain Research

Volume 6, Issue 4, December 1967, Pages 716-727
Brain Research

The formation of synaptic junctions in developing rat brain: A quantitative electron microscopic study

https://doi.org/10.1016/0006-8993(67)90128-XGet rights and content

Abstract

The formation of synaptic junctions in developing rat brain has been studied with the electron microscope, utilizing a selective staining method. In this procedure, glutaraldehyde-fixed tissue is not exposed to osmium tetroxide, but instead is blockstained with phosphotungstic acid in solution of ethanol. A selective staining of the paramembranous components of synaptic junctions results from this treatment, thus facilitating a quantification of the numerical density of synaptic junctions over large areas of sections.

It was found that a sharp increase in the number of synaptic junctions occurs in rat cortex (molecular layer) during the 3rd and 4th postnatal weeks. The relationship between this increase in the numerical density of synaptic junctions and other events during development, such as the maturation of the EEG, is discussed. In addition, it is proposed that synaptic junctions evolve through several stages and a tentative morphogenetic scheme is presented.

References (31)

  • BungeR.P. et al.

    Ultrastructural characteristics of synapses forming in cultured spinal cord

    Anat. Rec.

    (1965)
  • ClementiF. et al.

    The yield of synaptosomes from the cerebral cortex of guinea pigs estimated by a polystyrene bead ‘tagging’ procedure

    Z. Zellforsch.

    (1966)
  • ColonnierM. et al.

    Synaptic organization in the lateral geniculate nucleus of the monkey

    Z. Zellforsch.

    (1964)
  • CrainS.M.

    Development of electrical activity in the cerebral cortex of the albino rat

  • EayrsJ.T. et al.

    Postnatal development of the cerebral cortex in the rat

    J. Anat. (Lond.)

    (1959)
  • Cited by (578)

    • Super-resolved 3D-STED microscopy identifies a layer-specific increase in excitatory synapses in the hippocampal CA1 region of Neuroligin-3 KO mice

      2021, Biochemical and Biophysical Research Communications
      Citation Excerpt :

      Together with an increase in mEPSC in the PTPδ-binding deficient mutant of Nlgn3, our data in Fig. 2A demonstrate a potentially pivotal role of Nlgn3 in the suppression of excitatory synapse formation. In the rodent cortex and hippocampus, the excitatory synapses number increases until P20–P30 and declines gradually [15,16,21,22]. It is believed that synaptogenesis is repressed and the synapse elimination accelerates around this stage, and that this stage corresponds to the critical period in human brain development [23].

    • L-Dopa treatment during perinatal development leads to different behavioral alterations in female vs. male juvenile Swiss mice

      2018, Pharmacology Biochemistry and Behavior
      Citation Excerpt :

      For example, during prenatal development, phenomena like neurogenesis, neuronal migration, and cell differentiation are very pronounced (Bayer et al., 1993; McConnell, 1990; O'Rourke et al., 1992). During early postnatal development there is an increase in synaptogenesis and apoptosis (Aghajanian and Bloom, 1967; Blaschke et al., 1998). Furthermore, there are ontogenetic sex differences during brain development (Tobet et al., 2009).

    View all citing articles on Scopus
    View full text