Funding for this research was provided by:
National Institute on Drug Abuse (K08DA045575)
Received: 3 September 2018
Revised: 9 May 2019
Accepted: 14 May 2019
First Online: 5 November 2019
Compliance with Ethical Standards
: All the authors declare that they have no conflict of interest.
: This article does not contain any studies with human participants or animals performed by the authors.