Spectral editing in H-1 magnetic resonance spectroscopy: Experts' consensus recommendations
NMR IN BIOMEDICINE
Authors: Choi, In-Young; Andronesi, Ovidiu C.; Barker, Peter; Bogner, Wolfgang; Edden, Richard A. E.; Kaiser, Lana G.; Lee, Phil; Marjanska, Malgorzata; Terpstra, Melissa; de Graaf, Robin A.
Abstract
Spectral editing in in vivo(1)H-MRS provides an effective means to measure low-concentration metabolite signals that cannot be reliably measured by conventional MRS techniques due to signal overlap, for example, gamma-aminobutyric acid, glutathione and D-2-hydroxyglutarate. Spectral editing strategies utilize knownJ-coupling relationships within the metabolite of interest to discriminate their resonances from overlying signals. This consensus recommendation paper provides a brief overview of commonly used homonuclear editing techniques and considerations for data acquisition, processing and quantification. Also, we have listed the experts' recommendations for minimum requirements to achieve adequate spectral editing and reliable quantification. These include selecting the right editing sequence, dealing with frequency drift, handling unwanted coedited resonances, spectral fitting of edited spectra, setting up multicenter clinical trials and recommending sequence parameters to be reported in publications.
Ventral pallidal GABAergic neurons control wakefulness associated with motivation through the ventral tegmental pathway
MOLECULAR PSYCHIATRY
Authors: Li, Ya-Dong; Luo, Yan-Jia; Xu, Wei; Ge, Jing; Cherasse, Yoan; Wang, Yi-Qun; Lazarus, Michael; Qu, Wei-Min; Huang, Zhi-Li
Abstract
The ventral pallidum (VP) regulates motivation, drug addiction, and several behaviors that rely on heightened arousal. However, the role and underlying neural circuits of the VP in the control of wakefulness remain poorly understood. In the present study, we sought to elucidate the specific role of VP GABAergic neurons in controlling sleep-wake behaviors in mice. Fiber photometry revealed that the population activity of VP GABAergic neurons was increased during physiological transitions from non-rapid eye movement (non-REM, NREM) sleep to either wakefulness or REM sleep. Moreover, chemogenetic and optogenetic manipulations were leveraged to investigate a potential causal role of VP GABAergic neurons in initiating and/or maintaining arousal. In vivo optogenetic stimulation of VP GABAergic neurons innervating the ventral tegmental area (VTA) strongly promoted arousal via disinhibition of VTA dopaminergic neurons. Functional in vitro mapping revealed that VP GABAergic neurons, in principle, inhibited VTA GABAergic neurons but also inhibited VTA dopaminergic neurons. In addition, optogenetic stimulation of terminals of VP GABAergic neurons revealed that they promoted arousal by innervating the lateral hypothalamus, but not the mediodorsal thalamus or lateral habenula. The increased wakefulness chemogenetically evoked by VP GABAergic neuronal activation was completely abolished by pretreatment with dopaminergic D(1)and D-2/D(3)receptor antagonists. Furthermore, activation of VP GABAergic neurons increased exploration time in both the open-field and light-dark box tests but did not modulate depression-like behaviors or food intake. Finally, chemogenetic inhibition of VP GABAergic neurons decreased arousal. Taken together, our findings indicate that VP GABAergic neurons are essential for arousal related to motivation.