Spike timing dependent plasticity Domina Petric, MD 1

STDP Spike timing dependent plasticity is a framework for understanding plasticity in the brain: one postsynaptic spike at a time.

STDP When the presynaptic activity happens before the postsynaptic activity, there is long term potentiation (interval between presynaptic and postsynaptic activity has to be less than 20 ms). If the presynaptic activity happens after the postsynaptic activity, there is long term depression.

Hebb´s postulate Coordinated activity of a presynaptic terminal and a postsynaptic cell would strengthen the synaptic connection between them. Uncoordinated activity between the synaptic partners would weaken their synaptic connections.

Hebb´s postulate and STDP STDP explains how synaptic change can occur one postsynaptic spike at a time under physiological conditions that are found in real neural networks.

Hebb´s postulate and STDP Presynaptic activity that occurs before the postsynaptic activity is coordinated activity of a presynaptic terminal and a postsynaptic cell that will cause long term potentiation.

Hebb´s postulate and STDP Presynaptic activity Postsynaptic activity Before After Coordinated activity: long term potentiation 20 ms interval

Hebb´s postulate and STDP Postsynaptic activity that occurs before the presynaptic activity is uncoordinated activity of presynaptic terminal and a postsynaptic cell that will cause long term depression.

Hebb´s postulate and STDP Presynaptic activity Postsynaptic activity After Before Uncoordinated activity: long term depression 20 ms interval

Conclusion Change at the synaptic level can produce changes in wiring patterns of neuronal circuits. Synaptic changes accumulate throughout a network of interconnected neurons.

Literature https://www.coursera.org/learn/medical-neuroscience/lecture: Leonard E. White, PhD, Duke University