Neuroimage Research Papers - Academia.edu (original) (raw)

The anterior cingulate cortex (ACC) is thought to be the neuroanatomical interface between emotion and cognition. Because effective emotion-cognition interactions are essential to optimal decision making, clarifying how the functionality of the ACC changes in older age using functional imaging holds great promise for ultimately understanding what contributes to the psychological changes occurring in late life. However, the interpretation of functional imaging studies is complicated by the fact that aging is associated with changes in grey matter volume and in the cerebral vasculature. In the present study, we obtained high-resolution structural magnetic resonance (MR) imaging data and quantitative blood flow images to examine the association between aging, blood flow, and grey matter volume in the ACC. Twenty-six healthy individuals between 25 and 79 years of age underwent quantitative [ 15 O]water positron emission tomography (PET) imaging. The ACC was traced onto tissue-classified images derived from T1-and T2-weighted MRIs using previously defined methods. The ACC was divided into dorsal, rostral, and subgenual regions. Age was negatively correlated with blood flow in dorsal and rostral ACC regions. Effects were weaker but in a similar direction for the subgenual ACC. While older age and lower blood flow were both associated with smaller rostral ACC grey matter volumes, mediation analysis revealed that grey matter volume only partially mediated the effect of age on blood flow in the rostral ACC. Neural alterations not detectable on MR images may lead to reduced blood flow due to fewer and/or less metabolically active neurons. Alternatively, lower blood flow may be a cause, rather than a consequence, of smaller grey matter volume in the ACC. M., 2002. Changes in regional cerebral blood flow abnormalities in late-life depression following response to electroconvulsive therapy. Psychiatry Clin. Neurosci. 56, 31-40. Baron, R.M., Kenny, D.A., 1986. The moderator-mediator variable distinction in social psychological research: conceptual, strategic, and statistical considerations. J. Pers. Soc. Psychol. 51, 1173-1182. Bennett, S.A., Tenniswood, M., Chen, J.H., Davidson, C.M., Keyes, M.T., Fortin, T., Pappas, B.A., 1998. Chronic cerebral hypoperfusion elicits neuronal apoptosis and behavioral impairment. NeuroReport 9, 161-166. ., 2001. Hippocampal and anterior cingulate activation deficits in patients with geriatric depression. Am. J. Psychiatry 158, 1321-1323. Denburg, N.L., Recknor, E.C., Bechara, A., Tranel, D., 2006. Psychophysiological anticipation of positive outcomes promotes advantageous decision-making in normal older persons. Int. J. Psychophysiol. 61, 19-25. Devinsky, O., Morrell, M.J., Vogt, B.A., 1995. Contributions of anterior cingulate cortex to behaviour. Brain 118, 279-306.