Reducing tic-like behavior in D1CT-7 mouse models of Tourette syndrome through isoallopregnanolone

April 29, 2020 in College of Pharmacy, Virtual Poster Session Spring 2020

Abstract Tourette Syndrome (TS) is a semi-voluntary neuropsychiatric condition typified by motor and vocal manifestations known as tics. These tic episodes are generally provoked by stress exposures, although the exact mechanism is not well known. Acute stress has recently been shown to increase tic-like behavior through the well-established D1CT-7 mouse model of TS. This effect is promoted by neurosteroid synthesis of allopregnanolone (AP). Expanding on these findings, suppression of stress-induced tic-like behavior was seen as a result of AP synthesis inhibition through finasteride (FIN), while administration of AP showed profound increases in tic-like behavior. Because AP works primarily as a positive allosteric modulator at GABAA receptors, we aimed to show that either stress or AP induced increases in tic-like behavior could be mitigated by antagonizing AP binding of GABAA receptors with isoallopregnanolone (isoAP). We found that isoAP reduced tic-like behavior of D1CT-7 mice in a dose-dependent manner, and that this outcome was similar to those seen in both haloperidol, a hallmark TS therapy, and FIN. We also found AP induced tic-like behavior was successfully countered by isoAP. Because isoAP already has valid safety and tolerability profiles, our findings support its potential value in the TS armamentarium.