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Mushroom body output neurons encode valence and guide memory-based action selection in Drosophila.

Aso Y, Sitaraman D, Ichinose T, Kaun KR, Vogt K, Belliart-Guérin G, Plaçais PY, Robie AA, Yamagata N, Schnaitmann C, Rowell WJ, Johnston RM, Ngo TT, Chen N, Korff W, Nitabach MN, Heberlein U, Preat T, Branson KM, Tanimoto H, Rubin GM - Elife (2014)

Bottom Line: The behavioral effects of MBON perturbation are combinatorial, suggesting that the MBON ensemble collectively represents valence.We propose that local, stimulus-specific dopaminergic modulation selectively alters the balance within the MBON network for those stimuli.Our results suggest that valence encoded by the MBON ensemble biases memory-based action selection.

View Article: PubMed Central - PubMed

Affiliation: Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States.

ABSTRACT
Animals discriminate stimuli, learn their predictive value and use this knowledge to modify their behavior. In Drosophila, the mushroom body (MB) plays a key role in these processes. Sensory stimuli are sparsely represented by ∼2000 Kenyon cells, which converge onto 34 output neurons (MBONs) of 21 types. We studied the role of MBONs in several associative learning tasks and in sleep regulation, revealing the extent to which information flow is segregated into distinct channels and suggesting possible roles for the multi-layered MBON network. We also show that optogenetic activation of MBONs can, depending on cell type, induce repulsion or attraction in flies. The behavioral effects of MBON perturbation are combinatorial, suggesting that the MBON ensemble collectively represents valence. We propose that local, stimulus-specific dopaminergic modulation selectively alters the balance within the MBON network for those stimuli. Our results suggest that valence encoded by the MBON ensemble biases memory-based action selection.

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Related in: MedlinePlus

MBON activation has only small effects on walking and angular speeds.Walking speed (A) and angular speed (B) was calculated for individual trajectories, then averaged separately for all flies on dark and all flies on illuminated quadrants during the two 30 s light-on segments of one video (see Figure 2A). Approximately 20 flies were analyzed in each video. Bars and error bars show mean and standard error of the mean for videos (n = 11-43 for experimental groups; n = 66 for the pBDPGAL4U empty driver control). For comparison to the MBONs, values obtained with GAL4 drivers for other cell-types are shown: NP225, broad expression in antennal lobe projection neurons (Tanaka et al., 2004); Gr66a-GAL4, bitter taste receptor neurons (Dunipace et al., 2001); Ir76b-GAL4, co-receptor for ionotorpic receptors (Benton et al., 2009; Silbering et al., 2011); Gr63a-GAL4, CO2 receptor neurons (Dunipace et al., 2001); Or13a-GAL4 and Or49a-GAL4, olfactory receptor neurons (Fishilevich and Vosshall, 2005). Asterisk indicates significance (Kruskal–Wallis one-way analysis of variance followed by Dunns post-test) for comparison between light-off (left bar) and light-on (right bars) for the same genotype: *, p < 0.05; ***, p < 0.001. We found a weak correlation (Spearman's rank-order correlation: Pearson r = −0.60; R square = 0.36; p = 0.06) between absolute mean walking speed in illuminated quadrants and preference index to red light (Figure 4).DOI:http://dx.doi.org/10.7554/eLife.04580.012
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fig5s1: MBON activation has only small effects on walking and angular speeds.Walking speed (A) and angular speed (B) was calculated for individual trajectories, then averaged separately for all flies on dark and all flies on illuminated quadrants during the two 30 s light-on segments of one video (see Figure 2A). Approximately 20 flies were analyzed in each video. Bars and error bars show mean and standard error of the mean for videos (n = 11-43 for experimental groups; n = 66 for the pBDPGAL4U empty driver control). For comparison to the MBONs, values obtained with GAL4 drivers for other cell-types are shown: NP225, broad expression in antennal lobe projection neurons (Tanaka et al., 2004); Gr66a-GAL4, bitter taste receptor neurons (Dunipace et al., 2001); Ir76b-GAL4, co-receptor for ionotorpic receptors (Benton et al., 2009; Silbering et al., 2011); Gr63a-GAL4, CO2 receptor neurons (Dunipace et al., 2001); Or13a-GAL4 and Or49a-GAL4, olfactory receptor neurons (Fishilevich and Vosshall, 2005). Asterisk indicates significance (Kruskal–Wallis one-way analysis of variance followed by Dunns post-test) for comparison between light-off (left bar) and light-on (right bars) for the same genotype: *, p < 0.05; ***, p < 0.001. We found a weak correlation (Spearman's rank-order correlation: Pearson r = −0.60; R square = 0.36; p = 0.06) between absolute mean walking speed in illuminated quadrants and preference index to red light (Figure 4).DOI:http://dx.doi.org/10.7554/eLife.04580.012

Mentions: (A) Pseudo-colored light intensity in the behavioral arena. The choice zone was defined as ± 5 mm from the light ON/OFF border (green box). (B) Gradient of light intensity across the light ON/OFF border axis shown. (C) An example of MB434B + MB011B/UAS-CsChrimson fly that entered the choice zone from the light-off side at time = 0 and then stopped and quickly turned around to exit the choice zone, going back into the light-off side. Eleven images taken at 0.1 s intervals have been superimposed. Entry angle to the choice zone was defined as diagramed (top left). Speed and angular speed was calculated based on the difference in the position of a fly in successive frames of 30 frames per second video recordings. (D) The fraction of trajectories entering the choice zone from the dark side and then exiting to the illuminated side is plotted for the indicated drivers in combination with CsChrimson (top). The control genotype was the empty driver, pBDPGAL4U, in attP2 in combination with 20xUAS-CsChrimson-mVenus in attP18. Only flies that entered the choice zone at an entry angle of between 45 and 135° (facing to the light ON/OFF border) and had moved more than 5 mm in the 1 s prior to entering the choice zone were analyzed. The error bars show the 95% confidence interval. Between 79 and 410 trajectories were analyzed per genotype. Compared to the control, MB434B + MB011B, MB434B and MB011B showed a significantly lower fraction of trajectories that exit to the light-on side (more avoidance of light), whereas significantly higher fraction of trajectories of MB112C + MB077B flies exit to the light-on side (more attraction to the light); multiple comparisons with the Dunn-Sidak correction: ***, p < 0.001. Similarly, the fraction of trajectories entering the choice zone from the illuminated side and then changing direction so as to also exit to the illuminated side is plotted for the indicated drivers in combination with CsChrimson (bottom). Between 43 and 280 trajectories were analyzed per genotype. (E) Representative trajectories are shown for the indicated genotypes. The trajectories are color-coded to indicate the position of the fly in the trajectory as a function of time after entering the choice zone. The triangle shows the position of the fly at time = 0, when flies entered into the choice zone (indicated by the white line at −5 mm from the light ON/OFF border). The gray scale background in the panels and pseudo-color scale on the right indicate the intensity of CsChrimson activating light. (F) Preference index to the CsChrimson-activating light (Figure 4) was plotted against the fraction of trajectories that exit from the choice zone to the illuminated side irrespective of side of entry: [(number of trajectories enter to the choice zone from dark side and then exit to illuminated side) + (number of trajectories enter to the choice zone from illuminated side and then exit to illuminated side)] divided by total number of trajectories that entered into the choice zone. They were highly correlated (Spearman's rank-order correlation: Pearson r = 0.91; R square = 0.83; p < 0.001). Genotypes are the same as in panel D and are shown with same color code. (G) Preference index to the CsChrimson light (Figure 4) was plotted against the mean walking speed change in the illuminated quadrants compared to dark quadrants (see Figure 5—figure supplement 1). There was no significant correlation (Spearman's rank-order correlation: Pearson r = 0.13; R square = 0.01; p = 0.72). Genotypes are the same as in panel D and are shown with same color code. (H) Preference index to the CsChrimson light (Figure 4) was plotted against mean angular speed in the illuminated quadrants compared to dark quadrants (see Figure 5—figure supplement 1). There was no significant correlation (Spearman's rank-order correlation: Pearson r = 0.12; R square = 0.001; p = 0.75). Genotypes are the same as in panel D and are shown with same color code.


Mushroom body output neurons encode valence and guide memory-based action selection in Drosophila.

Aso Y, Sitaraman D, Ichinose T, Kaun KR, Vogt K, Belliart-Guérin G, Plaçais PY, Robie AA, Yamagata N, Schnaitmann C, Rowell WJ, Johnston RM, Ngo TT, Chen N, Korff W, Nitabach MN, Heberlein U, Preat T, Branson KM, Tanimoto H, Rubin GM - Elife (2014)

MBON activation has only small effects on walking and angular speeds.Walking speed (A) and angular speed (B) was calculated for individual trajectories, then averaged separately for all flies on dark and all flies on illuminated quadrants during the two 30 s light-on segments of one video (see Figure 2A). Approximately 20 flies were analyzed in each video. Bars and error bars show mean and standard error of the mean for videos (n = 11-43 for experimental groups; n = 66 for the pBDPGAL4U empty driver control). For comparison to the MBONs, values obtained with GAL4 drivers for other cell-types are shown: NP225, broad expression in antennal lobe projection neurons (Tanaka et al., 2004); Gr66a-GAL4, bitter taste receptor neurons (Dunipace et al., 2001); Ir76b-GAL4, co-receptor for ionotorpic receptors (Benton et al., 2009; Silbering et al., 2011); Gr63a-GAL4, CO2 receptor neurons (Dunipace et al., 2001); Or13a-GAL4 and Or49a-GAL4, olfactory receptor neurons (Fishilevich and Vosshall, 2005). Asterisk indicates significance (Kruskal–Wallis one-way analysis of variance followed by Dunns post-test) for comparison between light-off (left bar) and light-on (right bars) for the same genotype: *, p < 0.05; ***, p < 0.001. We found a weak correlation (Spearman's rank-order correlation: Pearson r = −0.60; R square = 0.36; p = 0.06) between absolute mean walking speed in illuminated quadrants and preference index to red light (Figure 4).DOI:http://dx.doi.org/10.7554/eLife.04580.012
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4273436&req=5

fig5s1: MBON activation has only small effects on walking and angular speeds.Walking speed (A) and angular speed (B) was calculated for individual trajectories, then averaged separately for all flies on dark and all flies on illuminated quadrants during the two 30 s light-on segments of one video (see Figure 2A). Approximately 20 flies were analyzed in each video. Bars and error bars show mean and standard error of the mean for videos (n = 11-43 for experimental groups; n = 66 for the pBDPGAL4U empty driver control). For comparison to the MBONs, values obtained with GAL4 drivers for other cell-types are shown: NP225, broad expression in antennal lobe projection neurons (Tanaka et al., 2004); Gr66a-GAL4, bitter taste receptor neurons (Dunipace et al., 2001); Ir76b-GAL4, co-receptor for ionotorpic receptors (Benton et al., 2009; Silbering et al., 2011); Gr63a-GAL4, CO2 receptor neurons (Dunipace et al., 2001); Or13a-GAL4 and Or49a-GAL4, olfactory receptor neurons (Fishilevich and Vosshall, 2005). Asterisk indicates significance (Kruskal–Wallis one-way analysis of variance followed by Dunns post-test) for comparison between light-off (left bar) and light-on (right bars) for the same genotype: *, p < 0.05; ***, p < 0.001. We found a weak correlation (Spearman's rank-order correlation: Pearson r = −0.60; R square = 0.36; p = 0.06) between absolute mean walking speed in illuminated quadrants and preference index to red light (Figure 4).DOI:http://dx.doi.org/10.7554/eLife.04580.012
Mentions: (A) Pseudo-colored light intensity in the behavioral arena. The choice zone was defined as ± 5 mm from the light ON/OFF border (green box). (B) Gradient of light intensity across the light ON/OFF border axis shown. (C) An example of MB434B + MB011B/UAS-CsChrimson fly that entered the choice zone from the light-off side at time = 0 and then stopped and quickly turned around to exit the choice zone, going back into the light-off side. Eleven images taken at 0.1 s intervals have been superimposed. Entry angle to the choice zone was defined as diagramed (top left). Speed and angular speed was calculated based on the difference in the position of a fly in successive frames of 30 frames per second video recordings. (D) The fraction of trajectories entering the choice zone from the dark side and then exiting to the illuminated side is plotted for the indicated drivers in combination with CsChrimson (top). The control genotype was the empty driver, pBDPGAL4U, in attP2 in combination with 20xUAS-CsChrimson-mVenus in attP18. Only flies that entered the choice zone at an entry angle of between 45 and 135° (facing to the light ON/OFF border) and had moved more than 5 mm in the 1 s prior to entering the choice zone were analyzed. The error bars show the 95% confidence interval. Between 79 and 410 trajectories were analyzed per genotype. Compared to the control, MB434B + MB011B, MB434B and MB011B showed a significantly lower fraction of trajectories that exit to the light-on side (more avoidance of light), whereas significantly higher fraction of trajectories of MB112C + MB077B flies exit to the light-on side (more attraction to the light); multiple comparisons with the Dunn-Sidak correction: ***, p < 0.001. Similarly, the fraction of trajectories entering the choice zone from the illuminated side and then changing direction so as to also exit to the illuminated side is plotted for the indicated drivers in combination with CsChrimson (bottom). Between 43 and 280 trajectories were analyzed per genotype. (E) Representative trajectories are shown for the indicated genotypes. The trajectories are color-coded to indicate the position of the fly in the trajectory as a function of time after entering the choice zone. The triangle shows the position of the fly at time = 0, when flies entered into the choice zone (indicated by the white line at −5 mm from the light ON/OFF border). The gray scale background in the panels and pseudo-color scale on the right indicate the intensity of CsChrimson activating light. (F) Preference index to the CsChrimson-activating light (Figure 4) was plotted against the fraction of trajectories that exit from the choice zone to the illuminated side irrespective of side of entry: [(number of trajectories enter to the choice zone from dark side and then exit to illuminated side) + (number of trajectories enter to the choice zone from illuminated side and then exit to illuminated side)] divided by total number of trajectories that entered into the choice zone. They were highly correlated (Spearman's rank-order correlation: Pearson r = 0.91; R square = 0.83; p < 0.001). Genotypes are the same as in panel D and are shown with same color code. (G) Preference index to the CsChrimson light (Figure 4) was plotted against the mean walking speed change in the illuminated quadrants compared to dark quadrants (see Figure 5—figure supplement 1). There was no significant correlation (Spearman's rank-order correlation: Pearson r = 0.13; R square = 0.01; p = 0.72). Genotypes are the same as in panel D and are shown with same color code. (H) Preference index to the CsChrimson light (Figure 4) was plotted against mean angular speed in the illuminated quadrants compared to dark quadrants (see Figure 5—figure supplement 1). There was no significant correlation (Spearman's rank-order correlation: Pearson r = 0.12; R square = 0.001; p = 0.75). Genotypes are the same as in panel D and are shown with same color code.

Bottom Line: The behavioral effects of MBON perturbation are combinatorial, suggesting that the MBON ensemble collectively represents valence.We propose that local, stimulus-specific dopaminergic modulation selectively alters the balance within the MBON network for those stimuli.Our results suggest that valence encoded by the MBON ensemble biases memory-based action selection.

View Article: PubMed Central - PubMed

Affiliation: Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States.

ABSTRACT
Animals discriminate stimuli, learn their predictive value and use this knowledge to modify their behavior. In Drosophila, the mushroom body (MB) plays a key role in these processes. Sensory stimuli are sparsely represented by ∼2000 Kenyon cells, which converge onto 34 output neurons (MBONs) of 21 types. We studied the role of MBONs in several associative learning tasks and in sleep regulation, revealing the extent to which information flow is segregated into distinct channels and suggesting possible roles for the multi-layered MBON network. We also show that optogenetic activation of MBONs can, depending on cell type, induce repulsion or attraction in flies. The behavioral effects of MBON perturbation are combinatorial, suggesting that the MBON ensemble collectively represents valence. We propose that local, stimulus-specific dopaminergic modulation selectively alters the balance within the MBON network for those stimuli. Our results suggest that valence encoded by the MBON ensemble biases memory-based action selection.

Show MeSH
Related in: MedlinePlus