EurekaMag.com logo
+ Translate

The presynaptic grid a new approach


, : The presynaptic grid a new approach. Brain Research 184(1): 23-40

A new EM facility is described which enables systematic visualization of E-PTA[ethanolic phosphotungstic acid]-stained presynaptic grids in full en face position. This EM-facility is used to analyze the size and the number of dense projections of synaptic grids in different brain areas of the rabbit. The view that dense projections form an intrinsic part of all central synapses and are organized in a hexagonal or triangular pattern is supported. The observation of annulate and horseshoe-shaped synaptic grids agrees with previous observations on synaptic connections with subsynaptic plate perforations. A non-normal frequency distribution of dense projections per synaptic grid with distinct peaks is suggestive of the existence of distinct size classes of synaptic contacts. Analyses of the frequency distribution of dense projections in different areas and at different levels below the pial surface in adult animals point to a specificity of the distinct size classes related to the afferent origin or the target cell on which they are projecting. Investigation or grid size and number of dense projections during a period of rapid synaptogenesis reveals that newly formed synapses also have a specific size. The complementarity of dense projections and vesicle attachment sites implicit in the model of Akert et al (1972) was used to calculate the number of vesicle attachment sites per sq. .mu.m because of the density of projections per grid. The agreement between these values and those of Akert and Peper (1975), based on the analyses of vesicle attachment sites in freeze-etch specimen, is striking. The possible implications of these observations in relation to synaptic efficacy and neuronal microcircuitry are discussed.

Accession: 006740097

PMID: 7357422

DOI: 10.1016/0006-8993(80)90585-5

Download PDF Full Text: The presynaptic grid a new approach


Submit PDF Full Text

No spam - Every submission is manually reviewed

Due to poor quality, we do not accept files from Researchgate

Submitted PDF Full Texts will always be free for everyone
(We only charge for PDFs that we need to acquire)

Select a PDF file:
Close
Close

Related references

Triller A.; Korn H., 1982: Distortions of the presynaptic grid associated with exocytosis at central synapses. Morphometric data, obtained at the level of terminal boutons known to mediate chemical inhibition of the Mauthner cell, show that the mean diameter of the necks of exocytotic vesicles is, during exocytosis, larger than that of the spaces which are...

Stepanov, S.S.; Semchenko, V.V., 1985: Effect of hypoxia on the structure of the presynaptic grid of the interneuronal contacts of the rat neocortex. Hypoxic effect (a 6 minute asphyxia) on the presynaptic grid structure and on the amount of synapses in the neocortex has been studied in white rats using the method of selective staining of synapses with phosphoric tungsten acid. Neurofilamentous...

Korn H., 1985: Deformations of the presynaptic grid associated with exocytotic activity in the central nervous system. Neuroscience Letters Supplement: 231

Stepanov S.S.; Semchenko V.V., 1985: Effect of hypoxia on the structure of presynaptic grid of interneuronal contacts in the cerebral cortex. Hypoxic effect (a 6 minute asphyxia) on the presynaptic grid structure and on the amount of synapses in the neocortex has been studied in white rats using the method of selective staining of synapses with phosphoric tungsten acid. Neurofilamentous...

Müller, L.; Pattiselanno, A.; Vrensen, G., 1981: The postnatal development of the presynaptic grid in the visual cortex of rabbits and the effect of dark-rearing. Brain Research 205(1): 39-48

Wood, M.R.; Cohen, M.J., 1980: Tannic acid enhances staining of the presynaptic vesicular grid in the lamprey spinal cord. Brain Research 194(2): 613-615

Muller L.; Pattiselanno A.; Vrensen G., 1981: Post natal development of the presynaptic grid in the visual cortex of rabbits and the effect of dark rearing. The postnatal development of synaptic contacts in the visual cortex of rabbits and the effects of long-term dark-rearing on this development were quantitatively investigated. The synaptic contacts are visualized in full en face extension using 0.5...

Molter, C.; Yamaguchi, Y., 2008: Impact of temporal coding of presynaptic entorhinal cortex grid cells on the formation of hippocampal place fields. Many behavioural experiments have pointed out the important role played by the hippocampus in spatial navigation. This role was enlightened by the discovery of hippocampal cells in rodents firing only at very specific locations in an environment,...

Anonymous, 2011: Retraction: Changing from computing grid to knowledge grid in life-science grid. Biotechnology Journal 6(1): 125-125

Konagaya, A., 2007: Trends in life science grid: from computing grid to knowledge grid. Background: Grid computing has great potential to become a standard cyberinfrastructure for life sciences which often require high-performance computing and large data handling which exceeds the computing capacity of a single institution.Results:...