Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Numerical relationships between geniculocortical afferents and pyramidal cell modules in cat primary visual cortex

A Peters1, B R Payne

  • 1Department of Anatomy and Neurobiology, Boston University School of Medicine, Massachusetts 02118.

Cerebral Cortex (New York, N.Y. : 1991)
|January 1, 1993
PubMed
Summary

Geniculocortical axons provide massive synaptic input to cat visual cortex layer IV neurons. However, this input constitutes only a small fraction of the total excitatory synapses received by these neurons.

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Levels of messenger-RNA coding for DNA topoisomerase-ii isoforms do not correlate with in-vitro drug-sensitivity.

Oncology reports·2011
Same author

Occurrence and concentration of dissolved silver in rivers in England and Wales.

Bulletin of environmental contamination and toxicology·2011
Same author

No evidence for general condition-dependence of structural plumage colour in blue tits: an experiment.

Journal of evolutionary biology·2011
Same author

Assessing the impact of East Coast Fever immunisation by the infection and treatment method in Tanzanian pastoralist systems.

Preventive veterinary medicine·2010
Same author

Prediction models for incident type 2 diabetes mellitus
in the older population: KORA S4/F4 cohort study.

Diabetic medicine : a journal of the British Diabetic Association·2010
Same author

Bose-Einstein condensation in microgravity.

Science (New York, N.Y.)·2010

Area of Science:

  • Neuroscience
  • Visual Cortex Anatomy
  • Synaptic Plasticity

Background:

  • The striate cortex (area 17) in cats is a key area for visual processing.
  • Layer IV neurons are primary recipients of geniculocortical input.
  • Understanding synaptic convergence is crucial for deciphering cortical processing.

Purpose of the Study:

  • To quantitatively analyze the convergence of geniculocortical axons onto pyramidal cell modules in cat striate cortex.
  • To estimate the number of synapses provided by X- and Y-axons to layer IV neurons.
  • To determine the proportion of excitatory input to layer IV neurons originating from the geniculocortical pathway.

Main Methods:

  • Quantitative analysis of anatomical data on neuronal structures.
  • Calculation of synaptic convergence ratios based on axonal overlap and synapse numbers.

Related Experiment Videos

  • Estimation of synaptic input from geniculocortical afferents relative to total input.

    • Main Results:

    • Enormous convergence of geniculocortical afferents onto layer IV pyramidal cell modules.
    • Overlap of 360-540 X-axons and 300-540 Y-axons per location.
    • Geniculocortical axons provide an estimated 1640 x 10^6 synapses to area 17.
    • This equates to 160-200 synapses per layer IV neuron (or 100-125 per spiny stellate cell).
    • Geniculocortical input represents only about 5% of the total excitatory input to layer IV neurons.

    Conclusions:

    • Despite massive convergence, geniculocortical afferents contribute a minor portion of the total excitatory input to layer IV neurons.
    • Individual geniculate axons are unlikely to dominate the activity of a single cortical neuron due to synapse distribution.
    • Further research is needed to understand the functional implications of this synaptic organization.