Figure 2.
Mediolateral comparison of slow phasic reversal categories. Neurons that were histologically confirmed to be in either the lateral nucleus accumbens (NAcc) (i.e. core\ventrolateral shell; n = 74) or the medial NAcc (i.e. dorsal shell\rostral pole shell; n = 17) were evaluated in terms of whether they exhibited: (i) progressive or late reversal patterns (n = 32); or (ii) early reversal patterns (n = 14). To determine whether reversal categories are differentially expressed in the NAcc, a chi-square analysis was conducted. The percentage of early-reversing neurons was greater in the medial NAcc, whereas progressive/late-reversing neurons were more prevalent in the lateral NAcc [χ2(exact) = 4.70, degrees of freedom = 1, *P < 0.05). A post hoc odds ratio analysis confirmed that the differential probability of observing the two different reversal categories between regions was significant (oddsPLR/oddsER = 5.37, *P < 0.05). PLR, progressive/late-reversing; ER, early-reversing; D, dorsal; RP, rostral pole; VL, ventrolateral