“…First, compared with naïve controls, exposed mice showed significantly decreased brain Ca 2+ activity in the depressive phase, which is consistent with macro-imaging findings suggesting that the disruption of the emotional network contributes to mood dysregulation in patients with BP (Drevets et al, 1997;Kempton et al, 2008;Bora et al, 2010;Ellison-Wright and Bullmore, 2010;Nortje et al, 2013;Hibar et al, 2018;Fries et al, 2019;Matsuo et al, 2019;Harrison et al, 2021). Second, brain Ca 2+ activity did not increase in the manic phase, inconsistent with some previous findings (Ghedim et al, 2012;Ettenberg et al, 2020;Gao et al, 2021). This difference could be explained by the design of our murine model, in which the mice received a ''double hit'' due to the use of CUMS followed 1 day later by ketamine, in contrast to models of ketamine-induced manic behavior alone.…”