(A) Upper left: schematic illustrates surgical manipulations for in vivo imaging experiments. Lower left: quantification of deafening-induced changes to syllable entropy and EV at 3 days post-deafening in LMAN intact (black) and LMAN lesion (red) birds (only syllables that underwent significant degradation by 3 days post-deafening are shown; song degradation analyzed in a total of 6 LMAN lesion birds (3 used for imaging) and 19 LMAN intact birds (13 used for imaging in Tschida and Mooney, 2012); entropy: 14 syllables from 10 LMAN intact birds, 5 syllables from 5 LMAN lesion birds; EV: 12 syllables from 9 LMAN intact birds, 8 syllables from 4 LMAN intact birds). Right: representative songs before and after deafening from LMAN lesion and LMAN intact birds. Deafened birds that received LMAN lesions still undergo subtle but significant song degradation. (B) Representative in vivo, two-photon images of HVCX neurons showing changes in spine size between 2 and 3 days post-deafening in deafened birds with or without LMAN lesions. LMAN lesions prevent the decrease in the size of HVCX spines that normally follows deafening (size index <1 in LMAN intact birds). Scale bars, 5 µm. (C) Spine size index (left) and spine stability (right) is significantly higher in deafened birds with LMAN lesions. Quantification of spine size (left) and stability (right) in HVCX neurons from deafened birds with (red) and without (black) LMAN lesions (LMAN intact data were previously reported in Tschida and Mooney (2012), except the values reported here have not been normalized to baseline, pre-deafening measurements). Time bins with significant differences between intact and LMAN lesion groups are indicated with asterisks (p<0.05).
© 2012, Elsevier Inc., All Rights Reserved. Figure 8, part (B) (images of HVCX dendrites from LMAN intact bird) is reprinted with permission from Figure 1B in Tschida and Mooney, 2012.