General Forms of LTD
Long-term depression can be described as either homosynaptic or heterosynaptic. Homosynaptic LTD is restricted to the individual synapse that is activated by a low frequency stimulus. In other words, this form of LTD is activity-dependent, because the events causing the synaptic weakening occur at the same synapse that is being activated. Homosynaptic LTD is also associative in that it correlates the activation of the postsynaptic neuron with the firing of the presynaptic neuron. Heterosynaptic LTD, in contrast, occurs at synapses that are not potentiated or are inactive. The weakening of a synapse is independent of the activity of the presynaptic or postsynaptic neurons as a result of the firing of a distinct modulatory interneuron. Thus, this form of LTD impacts synapses nearby those receiving action potentials.
Read more about this topic: Long-term Depression
Famous quotes containing the words general and/or forms:
“It is a maxim among these lawyers, that whatever hath been done before, may legally be done again: and therefore they take special care to record all the decisions formerly made against common justice and the general reason of mankind.”
—Jonathan Swift (1667–1745)
“Two forms move among the dead, high sleep
Who by his highness quiets them, high peace
Upon whose shoulders even the heavens rest,
Two brothers. And a third form, she that says
Good-by in the darkness, speaking quietly there,
To those that cannot say good-by themselves.”
—Wallace Stevens (1879–1955)