Different STDP rules found in different cells


In the dorsal cochlear nucleus, fusiform principal neurons and cartwheel inhibitory interneurons both have STDP, but they have different STDP rules.

In the fusiform cells:

  • when a spike followed an EPSP, LTP was induced
  • but when a spike preceded an EPSP, LTD was induced.

By contrast, in the cartwheel cells,:

  • At low to medium frequency input:
    • when a spike followed an EPSP, LTD was induced
    • when a spike preceded an EPSP, nothing happened.
  • At high frequency input:
    • when a spike followed an EPSP, LTP was induced
    • when a spike preceded an EPSP, LTP was induced

The article calls these Hebbian and anti-Hebbian learning, respectively.

In short, the hypothesized function of the circuit is: Hebbian learning is promoted by LTP at synapses onto the fusiform cell but also by LTD at the synapses onto the inhibitory cartwheel cell. As a check against runaway excitation of the fusiform cells, the inhibitory cartwheel cells switch to LTP when the input is too high-frequency.

The News & Views piece is a good read, and briefly gives a systems-level overview of how these learning rules could function. It also discusses the various divergent definitions of the phrase “anti-Hebbian” which have been used in the literature by various people.

The journal’s teaser for the article is “Opposing forms of spike timing-dependent plasticity act in concert at synapses onto different cell types in the auditory brainstem, leading to a net enhancement of sensory activation.”

Sacha B Nelson. News & Views: Hebb and anti-Hebb meet in the brainstem.
Nature Neuroscience 7, 687 – 688 (2004)

Thanos Tzounopoulos, Yuil Kim, Donata Oertel & Laurence O Trussell. Cell-specific, spike timing–dependent plasticities in the dorsal cochlear nucleus. Nature Neuroscience 7, 719 – 725 (2004).

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