Fig. 8

Ablation of posterior tuberculum (PT) OXT neurons affects social preference.

(A–C) Unilateral ablation of oxt:egfp cells using two-photon microscope. Region of interest for the targeted ablation of individual cells is outlined in red (A,B). Specimens were fixed 5 hr after ablation and were subjected to TUNEL staining (red) to detect apoptosis and verify lack of collateral damage to the surrounding cells/tissue (C). The ablated OXT neurons are marked by arrows (C). (D–F) Representative images taken before (D) and three days after (E) ablation of PT OXT neurons (marked by a red rectangle). (F) Percentage of the change in OXT cell number after the ablation procedure in the PT region and in the non-ablated NPO area (n = 5). Paired sample t-test indicated that the reduction in number of OXT cells in the PT was significant [t₍₄₎=3.738; **p=0.010] but not in the NPO [t₍₄₎=0.559; p=0.303]. (G–I) Graphs showing the analysis of visually mediated social preference (VMSP) test (see schemata in Figure 1E) comparing the place preference of PT OXT-ablated (n = 12) to non-ablated (n = 14) zebrafish. The time spent swimming in the social zone (G), non-social zone (H) and general locomotion (I; ‘distance moved’) were analyzed. (G) When comparing the ‘time in social zone’ between PT OXT ablated fish and non-ablated control, there is a trend for a difference in the second time bin (~p = 0.069) and a significant difference in the third time bin (*p=0.050). In addition, while the non-ablated group spends increasingly more time in the ‘social zone’ when compared to the first time bin (there is a significant main effect for ‘time’ in the non-ablated fish group (p=0.012); ^##p≤0.01 for the 1st bin and ^#p≤0.05 for the second bin), no significant effect for ‘time’ was found for the PT OXT-ablated group (p=0.166). (H) Time spent in the ‘non-social zone’ did not differ between the groups [F_(1,24)=0.212; p=0.649] and did not change throughout the test duration [F_(2,48)=2.300; p=0.135]. (I) The total distance moved in the arena did not differ between the groups [F_(1,24)=1.771; p=0.196] and did not change throughout the test duration [F_(2,48)=0.010; p=0.969].