Ma Jingyi, Leung L Stan
Department of Physiology and Pharmacology, The University of Western Ontario, London N6A 5C1, Canada.
Department of Physiology and Pharmacology, The University of Western Ontario, London N6A 5C1, Canada; Graduate Program in Neuroscience, The University of Western Ontario, London N6A 5C1, Canada.
Behav Brain Res. 2018 Feb 15;338:17-27. doi: 10.1016/j.bbr.2017.09.051. Epub 2017 Oct 7.
The involvement of posterior cingulate cortex (PCC) on ketamine-induced psychosis relevant behaviors was investigated in rats. Bilateral infusion of muscimol, a GABA receptor agonist, into the PCC significantly antagonized ketamine-induced deficit in prepulse inhibition of a startle reflex (PPI), deficit in gating of hippocampal auditory evoked potentials, and behavioral hyperlocomotion in a dose dependent manner. Local infusion of ketamine directly into the PCC also induced a PPI deficit. Systemic injection of ketamine (3mg/kg,s.c.) induced an increase in power of electrographic activity in the gamma band (30-100Hz) in both the PCC and the hippocampus; peak theta (4-10Hz) power was not significantly altered, but peak theta frequency was increased by ketamine. In order to exclude volume conduction from the hippocampus to PCC, inactivation of the hippocampus was made by local infusion of muscimol into the hippocampus prior to ketamine administration. Muscimol in the hippocampus effectively blocked ketamine-induced increase of gamma power in the hippocampus but not in the PCC, suggesting independent generation of gamma waves in PCC and hippocampus. It is suggested that the PCC is part of the brain network mediating ketamine-induced psychosis related behaviors.
在大鼠中研究了后扣带回皮质(PCC)与氯胺酮诱导的精神病相关行为的关系。向PCC双侧注入GABA受体激动剂蝇蕈醇,以剂量依赖的方式显著拮抗氯胺酮诱导的惊吓反射前脉冲抑制(PPI)缺陷、海马听觉诱发电位门控缺陷和行为性活动亢进。直接向PCC局部注入氯胺酮也会导致PPI缺陷。全身注射氯胺酮(3mg/kg,皮下注射)会导致PCC和海马γ波段(30-100Hz)的电图活动功率增加;θ波(4-10Hz)峰值功率没有显著改变,但氯胺酮会使θ波峰值频率增加。为了排除从海马到PCC的容积传导,在给予氯胺酮之前,通过向海马局部注入蝇蕈醇使海马失活。海马中的蝇蕈醇有效地阻断了氯胺酮诱导的海马γ功率增加,但对PCC没有影响,这表明PCC和海马中γ波的产生是独立的。提示PCC是介导氯胺酮诱导的精神病相关行为的脑网络的一部分。