Repeated 7-day exposure to ketamine induces anxiety-like behaviors and neuronal apoptosis in mice via DRD1-medicated inhibition of Akt/Gsk-3β phosphorylation.

Repeated ketamine exposure over seven days causes anxiety-like and depressive-like behaviors along with cognitive deficits in mice. The dopamine receptor DRD1 plays a key role in these effects: activating DRD1 produces anxiety-like behavior similar to ketamine and worsens ketamine's effects, while blocking DRD1 partially reduces anxiety but worsens depression. Ketamine triggers apoptosis (cell death) in HT22 cells by suppressing Akt/Gsk3β phosphorylation through DRD1. In mice, ketamine promotes neuronal apoptosis in the hippocampus and prefrontal cortex; blocking DRD1 partially reduces this apoptosis, but knocking down DRD1 in neurons unexpectedly increases both apoptosis and anxiety-like behavior.

Study at a glance

Abstract

Repeated exposure to ketamine leads to mental behavioral disorders and cognitive deficits in mice. As a neurotransmitter receptor, dopamine receptor 1 (DRD1) is involved in mental regulation and memory formation. However, the role of DRD1 in ketamine's behavioral disorder and neurotoxicity remains unclear. We found that seven-day ketamine exposure induced anxiety-like, depressive-like behavior and cognition dysfunction in mice. DRD1 activation can produce anxiety-like behavior similar to that induced by ketamine. Furthermore, DRD1 activation synergistically exacerbates this effect of ketamine, and DRD1 antagonism partially attenuates the anxiety-like behavior and further aggravated the depressive-like behavior induced by ketamine. Moreover, ketamine induced HT22 cell apoptosis by DRD1 dependent inhibition of Akt/Gsk3β phosphorylation. DRD1 agonist synergistically enhanced the apoptosis induced by ketamine, while DRD1 antagonist or the apoptosis inhibitor partially reversed this apoptosis in vitro. In vivo assay found that ketamine promotes neuronal apoptosis in the hippocampus and prefrontal cortex of mice, and antagonizing DRD1 partially attenuates ketamine-induced apoptosis. In contrast, cell-specific knockdown of DRD1 in neuronal cells exacerbated ketamine-induced neuronal apoptosis and anxiety-like behavior. In summary, ketamine regulates DRD1 to suppress Akt/Gsk3β phosphorylation, inducing neuronal apoptosis, ultimately leading to anxiety-like behaviors in mice.