Nonspecific synaptic plasticity improves the recognition of sparse patterns degraded by local noise

Sci Rep. 2017 Apr 20:7:46550. doi: 10.1038/srep46550.

Abstract

Many forms of synaptic plasticity require the local production of volatile or rapidly diffusing substances such as nitric oxide. The nonspecific plasticity these neuromodulators may induce at neighboring non-active synapses is thought to be detrimental for the specificity of memory storage. We show here that memory retrieval may benefit from this non-specific plasticity when the applied sparse binary input patterns are degraded by local noise. Simulations of a biophysically realistic model of a cerebellar Purkinje cell in a pattern recognition task show that, in the absence of noise, leakage of plasticity to adjacent synapses degrades the recognition of sparse static patterns. However, above a local noise level of 20%, the model with nonspecific plasticity outperforms the standard, specific model. The gain in performance is greatest when the spatial distribution of noise in the input matches the range of diffusion-induced plasticity. Hence non-specific plasticity may offer a benefit in noisy environments or when the pressure to generalize is strong.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Action Potentials / physiology*
  • Algorithms
  • Animals
  • Humans
  • Memory / physiology*
  • Models, Neurological
  • Nerve Net / physiology
  • Neuronal Plasticity / physiology*
  • Pattern Recognition, Physiological / physiology*
  • Purkinje Cells / physiology*
  • Synapses / physiology