ABSTRACT
In the current study, we sought to investigate whether T-type Ca channels (TCCs) in the brain are involved in generating post-anesthetic hyperexcitatory behaviors (PAHBs). We found that younger rat pups (postnatal days 9-11) had a higher incidence of PAHBs and higher PAHB scores than older pups (postnatal days 16-18) during emergence from sevoflurane anesthesia. The power spectrum of the theta oscillations (4 Hz-8 Hz) in the prefrontal cortex was significantly enhanced in younger pups when PAHBs occurred, while there were no significant changes in older pups. Both the power of theta oscillations and the level of PAHBs were significantly reduced by the administration of TCC inhibitors. Moreover, the sensitivity of TCCs in the medial dorsal thalamic nucleus to sevoflurane was found to increase with age by investigating the kinetic properties of TCCs in vitro. TCCs were activated by potentiated GABAergic depolarization with a sub-anesthetic dose of sevoflurane (1%). These data suggest that (1) TCCs in the brain contribute to the generation of PAHBs and the concomitant electroencephalographic changes; (2) the stronger inhibitory effect of sevoflurane contributes to the lack of PAHBs in older rats; and (3) the contribution of TCCs to PAHBs is not mediated by a direct effect of sevoflurane on TCCs.
ABSTRACT
Objective To explore the role of functional connectivity( FC) between the subgenual anterior cingulate cortes(sgACC) and limbic cortices in predicting the efficacy of early antidepressant treat-ment. Methods Resting state magnetoencephalography( MEG) data were collected from 32 patients with major depressive disorder(MDD) and 20 matched healthy control subjects at baseline.According to whether the HAMD17total score reduction rate reached 50% after 2 weeks,the patients were divided into responder group and non-responder group.The difference of the FC,the relationship between the FC and the change rate of HAMD17were explored. Results Compared with controls,MDD patients showed decreased connectivity of the sgACC with the right hippocampus(MNI coordinate:x＝30,y＝－3,z＝－24; F＝5.11,P＝0.028),the right amygdala(MNI coordinate:x＝22,y＝－2,z＝－15; F＝6.90,P＝0.012) and the left amygdala(MNI coordi- nate:x＝－24,y＝－6,z＝－16; F＝5.75,P＝0.020).Compared with non-responders,the connectivity of the sgACC with the right hippocampus(MNI coordinate:x＝30,y＝－3,z＝－24;F＝8.74,P＝0.0065),the right a-mygdala(MNI coordinate:x＝22,y＝－2,z＝－15; F＝12.417,P＝0.0016) were higher in responders.Pretreat-ment connectivity of the sgACC with the right hippocampus(r＝－0.50,P＝0.0066),the right amygdala(r＝－0.56,P＝0.0018) were negatively correlated with clinical improvement.ROC analyses confirmed the value of the connectivity of sgACC with the right hippocampus(area under curve(AUC)＝0.71,P＝0.042),the right amygdala(AUC＝0.73,P＝0.029) in classifying responders versus non-responders in 2 weeks of treatment. Conclusion The decreased FC of the sgACC with the right hippocampus and the right amygdala at baseline is associated with a better improvement,which can potentially serve as a treatment outcome biomarker in ear-ly curative effect of depression.