The ventral tegmental area modulates intracortical microstimulation (ICMS)-evoked M1 activity in a time-dependent manner

Nobuo Kunori; Riichi Kajiwara; Ichiro Takashima

doi:10.1016/j.neulet.2016.01.047

The ventral tegmental area modulates intracortical microstimulation (ICMS)-evoked M1 activity in a time-dependent manner

Neurosci Lett. 2016 Mar 11:616:38-42. doi: 10.1016/j.neulet.2016.01.047. Epub 2016 Jan 28.

Authors

Nobuo Kunori¹, Riichi Kajiwara², Ichiro Takashima³

Affiliations

¹ Human Informatics Research Institute, National Institute of Advanced Industrial Science and Technology, 1-1-1 Umezono, Tsukuba 305-8568, Japan; Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8577, Japan; RIKEN Brain Science Institute, 2-1 Hirosawa, Wako 351-0198, Japan.
² Department of Electronics and Bioinformatics, Meiji University, Tama, Kawasaki 214-8571, Japan.
³ Human Informatics Research Institute, National Institute of Advanced Industrial Science and Technology, 1-1-1 Umezono, Tsukuba 305-8568, Japan; Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8577, Japan. Electronic address: i.takashima@aist.go.jp.

PMID: 26827719
DOI: 10.1016/j.neulet.2016.01.047

Abstract

Intracortical microstimulation (ICMS)-evoked neural activity combined with ventral tegmental area (VTA) stimulation was studied in rat primary motor cortex (M1). We used voltage-sensitive dye (VSD) imaging to analyze the spatiotemporal dynamics of M1 activity following VTA-M1 paired stimulation. VTA stimulation was preceded by M1 ICMS at inter-stimulus intervals (ISIs) of 15-350ms. VSD imaging showed an excitatory-inhibitory sequence of neural activity after composing VTA stimulus- and ICMS-induced M1 neural activity. To evaluate the net ICMS M1 response, the optical response to unpaired VTA stimulation was subtracted from the VTA-M1 paired response. This revealed that the net ICMS-evoked M1 neural activity was inhibited when the ISI was 30-50ms, but highly facilitated when the ISI was 100-350ms. These results suggest that VTA modulates M1 excitability in the order of tens to hundreds of milliseconds and might directly affect the motor command generation process in the M1.

Keywords: Intracortical microstimulation; Primary motor cortex; Ventral tegmental area; Voltage-sensitive dye imaging.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Brain / physiology*
Electric Stimulation
Male
Motor Cortex / physiology*
Rats, Wistar
Tegmentum Mesencephali / physiology*
Time Factors
Voltage-Sensitive Dye Imaging