Hot Off the Press – May 27, 2022
Published in Proceedings of the National Academy of Sciences (PNAS) by Dr. Kshitij Jadhav (2019 Predoctoral trainee at NIDA-IRP), Dr. Benjamin Boutrel (Ph.D. supervisor, University of Lausanne, Switzerland) and Dr. Carl Lupica (Project Supervisor, Electrophysiology Research Section, NIDA-IRP).
Adolescents are labelled as high risk-taking impulsive individuals despite knowledge of the risks associated with this behavior. This challenges prevailing theories of decreased top-down control of behavior thought to result from the still ‘under-developed’ prefrontal cortex in adolescence. In this new study, we found that adolescent rats demonstrated highly inflexible behaviors when making decisions in conflictual situations (for example, seeking food during mild electric shock) compared to adult rats. We found that this inflexible or compulsive behavior was associated with lower excitability of pyramidal neurons in the anterior insular cortex in adolescent rats, as well as a weaker excitatory synaptic input to these neurons. Surprisingly, there was no difference in the excitability of the pyramidal neurons in the prefrontal cortex of adolescent rats. We then found that activating the anterior insular cortex pyramidal neurons in adolescent rats with chemogenetics decreased the inflexible behavior. This indicates a central role for the immature or undeveloped insular cortex in the expression of inflexible compulsive behavior in adolescent rats that may also be present in adolescent humans.
In: Proc Natl Acad Sci U S A, vol. 119, no. 21, pp. e2121247119, 2022, ISSN: 1091-6490.