Ketamine Inhibits Ultrasound Stimulation-Induced Neuromodulation by Blocking Cortical Neuron Activity

Ultrasound Med Biol. 2018 Mar;44(3):635-646. doi: 10.1016/j.ultrasmedbio.2017.11.008. Epub 2017 Dec 21.

Abstract

Ultrasound (US) can be used to noninvasively stimulate brain activity. However, reproducible motor responses evoked by US are only elicited when the animal is in a light state of anesthesia. The present study investigated the effects of ketamine on US-induced motor responses and cortical neuronal activity. US was applied to the motor cortex of mice, and motor responses were evaluated based on robustness scores. Cortical neuronal activity was observed by fluorescence calcium imaging. US-induced motor responses were inhibited more than 20 min after ketamine injection, and US-triggered Ca2+ transients in cortical neurons were effectively blocked by ketamine. Our results indicate that ketamine suppresses US-triggered Ca2+ transients in cortical neurons and, therefore, inhibits US-induced motor responses in a deep anesthetic state.

Keywords: Cortical neuron; Ketamine; Neuromodulation; Ultrasound stimulation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Analgesics / pharmacology*
  • Animals
  • Ketamine / pharmacology*
  • Mice
  • Models, Animal
  • Motor Cortex / diagnostic imaging
  • Motor Cortex / drug effects*
  • Neurons / drug effects*
  • Optical Imaging
  • Physical Stimulation / methods*
  • Ultrasonics / methods*

Substances

  • Analgesics
  • Ketamine