Spike-timing-dependent synaptic modification induced by natural spike trains

Abstract

The strength of the connection between two neurons can be modified by activity, in a way that depends on the timing of neuronal firing on either side of the synapse. This spike-timing-dependent plasticity (STDP) has been studied by systematically varying the intervals between pre- and postsynaptic spikes. Here we studied how STDP operates in the context of more natural spike trains. We found that in visual cortical slices the contribution of each pre-/postsynaptic spike pair to synaptic modification depends not only on the interval between the pair, but also on the timing of preceding spikes. The efficacy of each spike in synaptic modification was suppressed by the preceding spike in the same neuron, occurring within several tens of milliseconds. The direction and magnitude of synaptic modifications induced by spike patterns recorded in vivo in response to natural visual stimuli were well predicted by incorporating the suppressive inter-spike interaction within each neuron. Thus, activity-induced synaptic modification depends not only on the relative spike timing between the neurons, but also on the spiking pattern within each neuron. For natural spike trains, the timing of the first spike in each burst is dominant in synaptic modification.

Asynchronous inputs alter excitability, spike timing, and topography in primary auditory cortex

“…Recent experiments demonstrating that input timing on the order of milliseconds can be the difference between synaptic strengthening and weakening provides a potential mechanism that would allow sensory statistics to precisely control the connectivity and temporal dynamics of large networks of neurons (Bi and Poo, 1999;Feldman, 2000;Froemke and Dan, 2002;Schuett et al, 2001;Song and Abbott, 2001;Song et al, 2000;Yao and Dan, 2001;Zhang et al, 1998). Network models that incorporate this form of Hebbian learning, called spike-timing dependent synaptic plasticity (STDP), are highly sensitive to changes in input correlation (Song and Abbott, 2001).…”

Spike-timing-dependent synaptic plasticity can form “zero lag links” for cortical oscillations.

“…However, for a neuronal network in oscillatory mode the synapses are exposed to pre-and postsynaptic spike trains rather than isolated spike pairs. Recent experiments assessed STDP induced by natural pre-and postsynaptic spike trains [4]. Changes induced by an isolated spike pair turned out to become suppressed by preceeding spikes in the same pair of neurons.…”

“…(C) Modiÿcation function of STDP with two exponentials, A+ exp(− t= +) for t ¡ 0 and A − exp(− t= − ) for t ¿ 0. Parameters as in [7,11] (thin line, A+ = 0:5%, + = 20 ms, A − = 0:525%, − = 20 ms) or [4] (thick line, A+ = 1:47%, + = 13:3 ms, A − = 0:73%, − = 34:5 ms). (D) Suppression of spike e cacy according to [4] during oscillatory activity.…”

“…Parameters as in [7,11] (thin line, A+ = 0:5%, + = 20 ms, A − = 0:525%, − = 20 ms) or [4] (thick line, A+ = 1:47%, + = 13:3 ms, A − = 0:73%, − = 34:5 ms). (D) Suppression of spike e cacy according to [4] during oscillatory activity. A spike at time ts ¡ t leads to an e cacy recovery pre (t) = 1 − exp(−(t − ts)= pre ) at the presynaptic site and post (t) = 1 − exp(−(t − ts)= post ) at the postsynaptic site.…”

“…A spike at time ts ¡ t leads to an e cacy recovery pre (t) = 1 − exp(−(t − ts)= pre ) at the presynaptic site and post (t) = 1 − exp(−(t − ts)= post ) at the postsynaptic site. Parameters pre = 28 ms and post = 88 ms as estimated for the additive model in [4]. [2].…”