Rawlings-Mortimer Florence, Dalley Jeffrey W
Department of Psychology, University of Cambridge, Cambridge, UK.
Department of Psychiatry, Herchel Smith Building for Brain and Mind Sciences, University of Cambridge, Cambridge, UK.
Brain Neurosci Adv. 2024 Dec 16;8:23982128241306549. doi: 10.1177/23982128241306549. eCollection 2024 Jan-Dec.
Although a role of the thalamus in different arousal and awareness states is well established, there is a surprising lack of knowledge on subregional specificity within this complex, multinucleated structure of the diencephalon. In their recent paper 'Extrasynaptic GABA-A receptors in central medial thalamus mediate anaesthesia in rats', Muheyati et al. evaluated whether GABA receptors expressed in the central medial (CM), paraventricular (PV) or lateral mediodorsal (MD) nuclei of the thalamus contribute to the loss of the righting reflex (LORR) in rats. Deficits in this reflex have previously been interpreted as a surrogate marker of altered levels of consciousness. Using a range of convergent techniques, the authors report the novel finding that delta subunit-expressing GABA receptors in the CM contribute to distinct awareness states. This important discovery implicates a tonic GABA-mediated conductance in the CM that may be relevant for minimally conscious states and other conditions of altered awareness.
虽然丘脑在不同的觉醒和意识状态中的作用已得到充分证实，但对于这个间脑的复杂多核结构内的亚区域特异性，人们却惊人地缺乏了解。在他们最近发表的论文《丘脑中央内侧核中的突触外GABA - A受体介导大鼠麻醉》中，穆赫亚蒂等人评估了丘脑中央内侧（CM）、室旁（PV）或外侧背内侧（MD）核中表达的GABA受体是否导致大鼠翻正反射消失（LORR）。此前，这种反射缺陷被解释为意识水平改变的替代指标。作者使用了一系列相互印证的技术，报告了一项新发现，即CM中表达δ亚基的GABA受体有助于形成不同的意识状态。这一重要发现表明，CM中存在一种由GABA介导的紧张性电导，这可能与最低意识状态和其他意识改变的情况有关。
