Evidence for associative plasticity in the human visual cortex

Brain Stimul. May-Jun 2019;12(3):705-713. doi: 10.1016/j.brs.2019.01.021. Epub 2019 Feb 1.

Abstract

Background: Repetitive convergent inputs to a single post-synaptic neuron can induce long-term potentiation (LTP) or depression (LTD) of synaptic activity in a spike timing-dependent manner.

Objective: Here we set a protocol of visual paired associative stimulation (vPAS) of the primary visual cortex (V1) in humans to induce persistent changes in the excitatory properties of V1 with a spike timing rule.

Methods: We provided convergent inputs to V1 by coupling transcranial magnetic stimulation (TMS) pulses of the occipital cortex with peripheral visual inputs, at four interstimulus intervals of -50/-25/+25/+50 ms relative to the visual evoked potential (VEP) P1 latency. We analysed VEP amplitude and delayed habituation before and up to 10 min after each vPAS protocol.

Results: VEP amplitude was reduced after vPAS+25. Delayed VEP habituation was increased after vPAS-25 while it was reduced after vPAS+25.

Conclusions: We provide evidence that associative bidirectional synaptic plasticity is a feature not only of the sensorimotor but also of the human visual system.

Keywords: Plasticity; Spike timing; Transcranial magnetic stimulation; Visual cortex; Visual evoked potential.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Association*
  • Evoked Potentials, Visual
  • Female
  • Habituation, Psychophysiologic
  • Humans
  • Male
  • Neuronal Plasticity*
  • Transcranial Magnetic Stimulation
  • Visual Cortex / physiology*