Kozak R, Brown HD, Bruno JP, Sarter M (2006) Prefrontal cholinergic modulation of attentional performance-associated increases in posterior parietal acetylcholine release. Neuroscience 2006 Abstracts 369.15. Society for Neuroscience, Atlanta, GA.
Summary: Increases in medial prefrontal cortex (mPFC) cholinergic activity were demonstrated to mediate attentional performance, particularly under conditions that require increases in attentional effort such as coping with the detrimental performance effects of distractors. Activation of the mPFC, in part as a result of cholinergic activity, is thought to orchestrate top-down effects for optimization of input processing elsewhere in the cortex. The cholinergic inputs to posterior cortical regions have been conceptualized as a branch of the PFC efferent circuitry mediating such top-down effects. Therefore, cholinergic inputs to the mPFC are expected to modulate performance-associated activation of cholinergic projections to the posterior parietal cortex (PPC). Furthermore, the mPFC modulatory influence should be particularly robust in response to performance challenges. This hypothesis was tested by assessing attentional performance-associated ACh release in the PPC in rats after removal of cholinergic inputs to the mPFC. Attentional task-performing animals were equipped with a guide cannula for insertion of a microdialysis probe into the PPC. Cholinergic projections to the mPFC and medial cingulate region were lesioned bilaterally by infusing 192-IgG saporin into the mPFC. Standard task performance of intact rats increased PPC ACh release by ~100% (over baseline).While lesioned animals’ standard task performance was mildly but significantly impaired, performance-associated increases in PPC ACh release in lesioned animals were higher than those observed in intact rats (150-200% over baseline). Presentation of the distractor impaired the performance of intact animals; the lesion exaggerated the detrimental effects of the distractor. In both intact and lesion animals, distractor performance-associated increases in PPC ACh release were higher than the increases observed during standard task performance. However, while peak ACh levels were observed immediately after distractor onset in intact rats, PPC ACh release in lesioned animals increased toward the end of the session, peaking 16 min after distractor termination. These data support the hypotheses that mPFC cholinergic inputs contribute to the regulation of PPC cholinergic activity, particularly following performance challenges.
Related Products: 192-IgG-SAP (Cat. #IT-01)