Precise Synaptic Efficacy Alignment Suggests Potentiation Dominated Learning
| Autor: | Daniel Miner, Jochen Triesch, Christoph Hartmann |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
Normalization (statistics) Dendritic spine Cognitive Neuroscience Dendritic Spines Long-Term Potentiation Models Neurological Neuroscience (miscellaneous) Action Potentials Dendritic branch lcsh:RC321-571 STDP 03 medical and health sciences Cellular and Molecular Neuroscience 0302 clinical medicine homeostasis Animals Learning synaptic scaling Computer Simulation SORN Kesten process Long-Term Synaptic Depression lcsh:Neurosciences. Biological psychiatry. Neuropsychiatry Original Research Stochastic Processes Synaptic scaling Stochastic process Long-term potentiation self-organization Sensory Systems 030104 developmental biology Recurrent neural network synaptic normalization plasticity Synapses Neural Networks Computer Psychology Neuroscience 030217 neurology & neurosurgery |
| Zdroj: | Frontiers in Neural Circuits Frontiers in Neural Circuits, Vol 9 (2016) |
| ISSN: | 1662-5110 |
| DOI: | 10.3389/fncir.2015.00090 |
| Popis: | Recent evidence suggests that parallel synapses from the same axonal branch onto the same dendritic branch have almost identical strength. It has been proposed that this alignment is only possible through learning rules that integrate activity over long time spans. However, learning mechanisms such as spike-timing-dependent plasticity (STDP) are commonly assumed to be temporally local. Here, we propose that the combination of temporally local STDP and a multiplicative synaptic normalization mechanism is sufficient to explain the alignment of parallel synapses. To address this issue, we introduce three increasingly complex models: First, we model the idealized interaction of STDP and synaptic normalization in a single neuron as a simple stochastic process and derive analytically that the alignment effect can be described by a so-called Kesten process. From this we can derive that synaptic efficacy alignment requires potentiation-dominated learning regimes. We verify these conditions in a single-neuron model with independent spiking activities but more realistic synapses. As expected, we only observe synaptic efficacy alignment for long-term potentiation-biased STDP. Finally, we explore how well the findings transfer to recurrent neural networks where the learning mechanisms interact with the correlated activity of the network. We find that due to the self-reinforcing correlations in recurrent circuits under STDP, alignment occurs for both long-term potentiation- and depression-biased STDP, because the learning will be potentiation dominated in both cases due to the potentiating events induced by correlated activity. This is in line with recent results demonstrating a dominance of potentiation over depression during waking and normalization during sleep. This leads us to predict that individual spine pairs will be more similar in the morning than they are after sleep depriviation. In conclusion, we show that synaptic normalization in conjunction with coordinated potentiation -- in this case, from STDP in the presence of correlated pre- and post-synaptic activity -- naturally leads to an alignment of parallel synapses. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|