An environment-dependent modulation of cortical neural response by forebrain cholinergic neurons in awake rat

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• 作者：Mohammed Zacky Ariffin^a ; ¹ ; Lai Seong Chang^a ; ¹ ; Han Chow Koh^a ; ¹ ; Chian-Ming Low^b ; ^c ; ^d ; Sanjay Khanna^a ; ^b ; ^{phsks@nus.edu.sg} ; ^{sanjay_khanna@nuhs.edu.sg}
• 关键词：Medial septum ; 192 IgG-saporin ; C-Fos ; Cingulate cortex ; Hippocampus ; Novelty
• 刊名：Brain Research
• 出版年：2013
• 出版时间：4 June, 2013
• 年：2013
• 卷：1513
• 期：Complete
• 页码：72-84
• 全文大小：1872 K

文摘

The forebrain cholinergic neurons project to cortex, including the hippocampus and the cingulate cortex (Cg). However, the relative influence of these neurons on behavior-linked neural processing in the two cortical areas remains unclear. We have now examined the effect of destruction of the cholinergic neurons with microinjection of the immunotoxin 192 IgG-saporin into the medial septum on the induction of c-Fos protein, an index of neuronal synaptic excitation, in the two forebrain areas to varied episodic experiences. Separate groups of rats were (a) re-exposed to the laboratory where they had previously undergone a surgery for intraseptal microinjection or (b) exposed to a novel environment. Re-exposure evoked a differential increase in the number of c-Fos positive neurons in dorsal CA1 compared to novelty, while a robust increase was observed in the Cg selectively in the novel environment. Both the differential and the selective increases were strongly attenuated by the cholinergic destruction with intraseptal-immunotoxin. These findings suggest that the cholinergic modulation of the neural processing in the two forebrain areas varies partly in an environment-dependent fashion affecting CA1 neural activation on repeat exposure to an environment where they had a relatively complex aversive experience while favoring Cg neural activation more during novelty.