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

作者：Ariffin Mohammed Zacky; Chang Lai Seong; Koh Han Chow; Low Chian Ming; Khanna Sanjay^*

来源：Brain Research, 2013, 1513: 72-84.

DOI：10.1016/j.brainres.2013.03.046

• Medial septum
• 192 IgG-saporin
• C-Fos
• Cingulate cortex
• Hippocampus
• Novelty

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.

• 出版日期2013-6-4