Involvement of the dorsal anterior cingulate cortex in temporal behavioralsequencing: subregional analysis of the medial prefrontal cortex in rat

We recently demonstrated that rats with dorsal anterior cingulate (AU) cort ical lesions were disrupted in the acquisition of a temporal Go/No-Go alter nation task, suggesting either an involvement of this medial prefrontal sub region in sequencing temporally ordered behaviors or alternatively in more general response selection processes 'Gisquet-Verrier et al., Psychobiology 28 (2000) 248'. In the present study, the effects of AU lesions were inves tigated in two different training situations. Both tasks involved response selection but only one of the two tasks required behavioral sequencing. In experiment 1, rats with AU lesions were normally able to select Go and No-G o responses, when selection processes were based on a tone/light conditiona l rule that does not require temporal patterning. In experiment 2, ACd-lesi oned rats were disrupted during the acquisition of a spatial alternation ta sk that relies on temporal patterning. These results provide further eviden ce of AU involvement in behavioral sequencing, regardless of the nature (sp atial or non-spatial) of chained responses. A comparison of AU lesions-indu ced effects with those obtained with lesions to the adjacent prelimbic-infr alimbic area 'Delatour & Gisquet-Verrier, Behav. Neurosci. 110 (1996) 1282, Delatour & Gisquet-Verrier, Behav. Neurosci. 113 (1999) 941' reveals a dou ble dissociation of these two regions that reflects a functional regionaliz ation of the medial prefrontal cortex in the rat. (C) 2001 Elsevier Science BV. All rights reserved.