Behrendt Ralf-Peter
The Retreat Hospital, Heslington Road, York, UK.
J Psychopharmacol. 2006 May;20(3):356-72. doi: 10.1177/0269881105057696. Epub 2005 Sep 20.
Cholinergic arousal mechanisms predispose thalamic and cortical neurons to fire action potentials at gamma rhythms, which have a tendency to resonate in thalamocortical networks, thereby forming coherent assemblies under constraints of sensory input to specific thalamic nuclei, on the one hand, and prefrontal and limbic attentional mechanisms, on the other. Perception may be based on sustained assemblies of coherent gamma oscillations in thalamocortical circuits. In schizophrenia, the impact of sensory input on self-organization of thalamocortical activity may be generally reduced. As a result, processes underlying perception can become uncoupled from sensory input, particularly at times of hyperarousal, leading to domination of attentional mechanisms and the emergence of hallucinations. Evidence is reviewed that implicates excessive neuronal noise in specific thalamic nuclei in the generation of hallucinations in schizophrenia. Nicotinic receptor abnormalities, dopaminergic hyperactivity and glutamate-receptor hypofunction are reconciled within a model of psychotic symptom generation that places crucial emphasis on dysfunction of the reticular thalamic nucleus.
胆碱能唤醒机制使丘脑和皮层神经元易于以γ节律发放动作电位，这种节律倾向于在丘脑皮质网络中产生共振，从而一方面在特定丘脑核的感觉输入约束下，另一方面在前额叶和边缘注意机制的约束下形成连贯的集合。感知可能基于丘脑皮质回路中持续的连贯γ振荡集合。在精神分裂症中，感觉输入对丘脑皮质活动自组织的影响可能普遍降低。因此，感知的基础过程可能与感觉输入脱耦，尤其是在过度唤醒时，导致注意机制占主导并出现幻觉。本文综述了相关证据，表明精神分裂症幻觉产生中特定丘脑核内存在过多的神经元噪声。烟碱受体异常、多巴胺能亢进和谷氨酸受体功能低下在一个强调丘脑网状核功能障碍的精神病症状产生模型中得到了协调。
