de Souza Ingrid Brasilino Montenegro Bento, Meurer Ywlliane da Silva Rodrigues, Tavares Priscila Macedo, Pugliane Karen Cristina, Lima Ramón Hypolito, Silva Regina Helena, Barbosa Flávio Freitas
Memory and Cognition Studies Laboratory, Department of Psychology, Federal University of Paraíba, João Pessoa, PB, Brazil; Behavioural Pharmacology Laboratory, Department of Biophysics and Pharmacology, Federal University of Rio Grande do Norte, Natal, RN, Brazil.
Physiology and Behaviour Department, Federal University of Rio Grande do Norte, Natal, Brazil.
Behav Brain Res. 2019 Feb 1;359:165-171. doi: 10.1016/j.bbr.2018.10.031. Epub 2018 Oct 22.
Episodic-like memory refers to integration of where and when a certain event (what) happened. The glutamatergic neurotransmission, particularly AMPA and NMDA receptors, in the dorsal hippocampus mediates episodic recall. Ketamine is a non-competitive NMDA antagonist with effect on cognitive performance and plasticity. The goal of this study was to evaluate the acute action of ketamine on behavioural and neurochemical aspects of episodic-like memory (WWWhen/ELM task) through immediate-early gene expression (IEG), c-Fos, in the dorsal hippocampus. Animals received saline 0.9% or ketamine at 8 mg/kg or 15 mg/kg (i.p.) immediately after the second sample. Our data indicate that untreated and saline rats integrate the three elements of episodic-like memory. Conversely, animals treated with ketamine showed impairment of ELM formation. In addition, the highest dose of ketamine increased c-Fos expression in dorsal CA1 subregion when compared to saline rats. Our results indicate that the antagonism of NMDA concurrently impair ELM formation of all three aspects of ELM and increase neuronal activation in dorsal CA1.
情景样记忆是指对特定事件（何事）发生的地点和时间的整合。背侧海马体中的谷氨酸能神经传递，尤其是AMPA和NMDA受体，介导情景回忆。氯胺酮是一种非竞争性NMDA拮抗剂，对认知表现和可塑性有影响。本研究的目的是通过背侧海马体中即刻早期基因c-Fos的表达，评估氯胺酮对情景样记忆（WWWhen/ELM任务）行为和神经化学方面的急性作用。在第二个样本采集后，动物立即接受0.9%生理盐水或8mg/kg或15mg/kg（腹腔注射）的氯胺酮。我们的数据表明，未处理的大鼠和生理盐水处理的大鼠整合了情景样记忆的三个要素。相反，氯胺酮处理的动物表现出情景样记忆形成受损。此外，与生理盐水处理的大鼠相比，氯胺酮最高剂量组背侧CA1亚区的c-Fos表达增加。我们的结果表明，NMDA拮抗作用同时损害情景样记忆所有三个方面的形成，并增加背侧CA1区的神经元激活。
