Self-learning and world-learning
operant behavior Behavior
heat
world learning self
learning
PKC/FoxP cAMP
Habits
color
dependent
MB
The what and where of operant self-learning mechanisms in Drosophila
Julien Colomb, Ezequiel Mendoza, Diana Pauly, Sathishkumar Raja, Björn Brembs
Freie Universität Berlin, Institut für Biologie - Neurobiologie, Berlin, Germany
bjoern@brembs.net, http://brembs.net
P 279
Presented at the 9
thInternational Congress of Neuroethology in Salamanca, August 2-7, 2010.
1. PKC activity is required specifically for self-learning
1. PKC activity is required specifically for self-learning
Fig. 2: FoxP function dissociates between self- and world-learning.
Canton S and genetic control lines perform well in both learning situations, whereas a FoxP mutant line and a FoxP RNAi line show significantly reduced learning scores specifically in the self-learning task.
Fig. 2: FoxP function dissociates between self- and world-learning.
Canton S and genetic control lines perform well in both learning situations, whereas a FoxP mutant line and a FoxP RNAi line show significantly reduced learning scores specifically in the self-learning task.
torque meter
yaw torque signal
diffusor light guides light source
IR laser diode Control
Behavior
heat
WT cAMP PKC MB
OK OK Impaired OK self l.
torque meter
yaw torque signal
diffusor light guides light source
IR laser diode
solenoid
color filter
Control
WT cAMP PKC MB
OK Impaired OK OK Behavior
heat color
world l.
self l.
0.0 0.2 0.4 0.6
22 21 36 29
CS FoxP FoxP-RNAi genetic controls
0.0 0.2 0.4 0.6
p<0.05 p<0.02
22 20 37 30
PI [rel. units]
self- and world-learning
only self-learning
2. Drosophila FoxP is required specifically for self-learning
2. Drosophila FoxP is required specifically for self-learning
−0.2
3. Screening PKC isoforms 3. Screening PKC isoforms
0.0 0.2 0.4 0.6 0.8 1.0
Mutants
PKC InaC(eye-PKC) (II) PKC 98E (III) PKC 53E (III) PKC delta (X)
DaPKC (II)
PKC related (II)
RNAi
Four tested for specificity and viable (Chen et al.)
J. CHEN, Y. ZHANG AND P. SHEN* 2010
J. CHEN, Y. ZHANG AND P. SHEN* 2008
6 putative mutants:
2 homozygous lethal, 1 not flying 1 in outcross
2 tested: no defect
wtb ( 15 ) PKC-inac ( 15 )
**
score pretest pretest training training test training training test test
PKC53E ( 13 ) wtb ( 16 )
*
−0.2 0.0 0.2 0.4 0.6 0.8 1.0
pretest pretest training training test training training test test
PKC InaC
n=15PKC 53E
n=13self-learning
Fig. 3: We are currently in the process of screening various mutant and RNAi lines affecting different PKC isoforms. Two viable, flying mutant lines have been tested in self-learning and are not impaired.
Fig. 3: We are currently in the process of screening various mutant and RNAi lines affecting different PKC isoforms. Two viable, flying mutant lines have been tested in self-learning and are not impaired.
532bp 1347bp
1000bp 500bp
CS CS Fo xP Fo xP
N TC N TC
4. FoxP is not transcribed in the mutant line
Fig. 4: Primer pairs directed against each of the two FoxP isoforms (left) do not lead to any amplificate in the FoxP mutant line.
Fig. 4: Primer pairs directed against each of the two FoxP isoforms (left) do not lead to any amplificate in the FoxP mutant line.
Fig. 5: ELISA results after seven immunizations of four chicken immunized with peptides from different regions in the FoxP sequence. No specific immunoresponse, yet.
ab1 ab2 ab3 ab4
5. Developing antibodies against Drosophila FoxP
Fig. 1: Two operant conditioning experiments, distinguished by the presence or absence of predictive stimuli. Above: Flies learn to avoid the heat associated with one of two colors and left or right turning, respectively. Manipulating cAMP levels abolishes learning in this task. Below: Removing the color stimuli leaves the animal with only its behavior as predictor of heat punishment. Manipulating PKC abolishes learning in this task. Brembs & Plendl, Curr. Biol. 2008
inc82
6. No obvious brain defects in FoxP mutants
Fig. 6: FoxP mutant brains do not seem to be obviously malformed. A quantitative anatomical analysis searching for more subtle defects is currently under way.
Fig. 6: FoxP mutant brains do not seem to be obviously malformed. A quantitative anatomical analysis searching for more subtle defects is currently under way.
