exam 2 learning in a natural environment special case... flower learning

1. PART 4: BEHAVIORAL PLASTICITY #19: ASSOCIATIVE LEARNING IN HONEYBEES II • exam 2 • learning in a natural environment • special case... flower learning • odor learning in the proboscis extension reflex • summary

2. PART 4: BEHAVIORAL PLASTICITY #19: ASSOCIATIVE LEARNING IN HONEYBEES II • exam 2 • learning in a natural environment • special case... flower learning • odor learning in the proboscis extension reflex • summary

3. SEMINAR • Dr. Spence Behmer • Department of Entomology, Texas A & M University • Friday, April 6th @ 3:30 WHI Auditorium • Grasshoppers and nutritional physiology: from learning to community structure • to supplement your enjoyment or if you can’t make the seminar… literature will be posted • be ready for one bonus question on the final

4. ODOR LEARNING & PROBOSCIS EXTENTION REFLEX • PER from sucrose contact on proboscis or antennae • reliable in hungry bees • studied in the laboratory • used with odor for conditioning • some simple rules for learning...

5. ODOR LEARNING & PROBOSCIS EXTENTION REFLEX • odor by itself does not elicit PER • classical or Pavlovian conditioning • US = sucrose • UR = PER • CS = odor • training: US + CS • test: CR = PER • bees learn that odor predicts sucrose reward

6. ODOR LEARNING & PROBOSCIS EXTENTION REFLEX • in color experiment • classical or Pavlovian conditioning • US = sucrose • UR = feeding • CS = color • training: US + CS • test: CR =  preference • bees learn that color predicts sucrose reward

7. ODOR LEARNING & PROBOSCIS EXTENTION REFLEX • CS (e.g., color) must precede US (sucrose)

8. ODOR LEARNING & PROBOSCIS EXTENTION REFLEX • CS (e.g., pattern) must precede US (e.g., sucrose) • can use 2 CS stimuli = differential conditioning • CS+ = paired with US • CS– = not paired with US • CR = shift in preference for either training testing

9. odor “B” (CS–) odor “A” (CS+) + shock (US) flies  choice point ODOR LEARNING & PROBOSCIS EXTENTION REFLEX • CS (e.g., odor) must precede US (e.g., shock) • can use 2 CS stimuli = differential conditioning • CS+ = paired with US • CS– = not paired with US • CR = shift in preference for either training testing

10. ODOR LEARNING & PROBOSCIS EXTENTION REFLEX • CS (e.g., odor) must precede US (e.g., shock) • timing critical • determine interstimulus interval function

11. ODOR LEARNING & PROBOSCIS EXTENTION REFLEX • interstimulus interval function determination in PER • CS = geraniol odor • US = sucrose • optimal response when CS preceeds US by 2-3s

12. ODOR LEARNING & PROBOSCIS EXTENTION REFLEX • interstimulus interval function determination in PER • similar to color learning in free flying bees • CS = color • US = sucrose • optimal response when CS preceeds US by 2-3s

13. ODOR LEARNING & PROBOSCIS EXTENTION REFLEX • acquisition function determination in PER • how fast do bees learn? • CS = odor • US = sucrose • asymptotic response with 3 trials • excitatory or faciliatory conditioning leads to CR 

14. ODOR LEARNING & PROBOSCIS EXTENTION REFLEX • CS as predictor of the absence of US • how does unpaired CS pre-exposure influence CR? • CS = odor • US = sucrose • inhibitory conditioning reduces effect of training • CS is a less reliable predictor of US for the bees

15. ODOR LEARNING & PROBOSCIS EXTENTION REFLEX • differential conditioning in PER • can it be reversed? • CS+ = odor A paired • CS– = odor B unpaired • US = sucrose • 1st generalize to odor, then differentiate with training • CR+ & CR– are opposite • reversal training = retrain bees to alternate odors

16. ANATOMY OF PER • insect brains ~ vertebrate brains • fewer neurons • ~ complexity

17. ANATOMY OF PER • insect brains ~ vertebrate brains • fewer neurons • ~ complexity • e.g., Drosophila

18. ANATOMY OF PER • insect brains ~ vertebrate brains • fewer neurons • ~ complexity • e.g., Drosophila • sensory input

19. ANATOMY OF PER • insect brains ~ vertebrate brains • fewer neurons • ~ complexity • e.g., Drosophila • sensory input • motor output

20. ANATOMY OF PER • insect brains ~ vertebrate brains • fewer neurons • ~ complexity • e.g., Drosophila • sensory input • motor output • processing

21. ANATOMY OF PER • insect brains ~ vertebrate brains • fewer neurons • ~ complexity • e.g., Drosophila • sensory input • motor output • processing • neuropile • cell bodies

22. ANATOMY OF PER • honeybee brain • ~ 106 neurons • complex • what neuropiles mediate PER?

23. ANATOMY OF PER • honeybee brain • ~ 106 neurons • complex • what neuropiles mediate PER? • CS

24. ANATOMY OF PER • honeybee brain • ~ 106 neurons • complex • what neuropiles mediate PER? • CS • US + “VUM”

25. ANATOMY OF PER • honeybee brain • ~ 106 neurons • complex • what neuropiles mediate PER? • CS • US • CS + US convergence?

26. ANATOMY OF PER • CS + US convergence? • 3 regions tested using bilateral cooling: • antennal lobe • mushroom body -lobe • mushroom body -lobe

27. ANATOMY OF PER • CS + US convergence? • 3 regions tested using bilateral cooling: • antennal lobe • mushroom body -lobe • mushroom body -lobe

28. ANATOMY OF PER • CS + US convergence? • 3 regions tested using bilateral cooling: • antennal lobe • mushroom body -lobe • mushroom body -lobe • distributed function • MB most critical

29. ANATOMY OF PER • CS + US convergence? • two specific neurons tested for PER functions: • PE1 • VUMmx1

30. ANATOMY OF PER • CS + US convergence? • PE1 • dye filled

31. ANATOMY OF PER • CS + US convergence? • PE1 • intracellular recordings • reduced response after training

32. ANATOMY OF PER • CS + US convergence? • PE1 • intracellular recordings • qualitative change in response with multiple trials • may be change in PE1 or change in KC input • suggest PE1 involvement in memory acquisition

33. ANATOMY OF PER • CS + US convergence? • VUMmx1 • ventral unpaired medial • dye filled • VERY extensive pattern of arborization • all areas of CS & US input

34. ANATOMY OF PER • CS + US convergence? • VUMmx1 • intracellular recording • fires in response to sucrose application • triggers neural circuit  proboscis extension*

35. ANATOMY OF PER • CS + US convergence? • VUMmx1 • substitute sugar with injected current • measurement of PER* • VUMmx1 provides US • current alone does  UR • separates sensory from US at neural level

36. ANATOMY OF PER • CS + US convergence? • VUMmx1 • intracellular recordings •  spikes with forward conditioning only

37. ANATOMY OF PER • CS + US convergence? • VUMmx1 • differential conditioning • intracellular recordings • responds to CS+ only

38. ANATOMY OF PER • CS + US convergence? • VUMmx1 • 1st order conditioning • train: CS1 (odor A) + US1 (sugar) • test: CS1  CR1 (PER) • 2nd order conditioning • train: CS2 (odor B) + CS1 (odor A = US2) • test: CS2  CR2 (PER = CR1)

39. ANATOMY OF PER • CS + US convergence? • VUMmx1 • octopamine transmitter • substitute sugar with octopamine injection @ • calyx • antennal lobe • measurement of PER* • VUMmx1 provides US

40. LEARNING IN HONEYBEES: SUMMARY • learning necessary for survival in nature • several forms of learning • several modalities of learning • rapid learning • permanent memory in 3 trials • temporal requirements of learning critical • waggle dance • integrate stimuli • can learn complex patterns • can learn general environmental features

41. LEARNING IN HONEYBEES: SUMMARY • proboscis extension reflex (PER) • show all features of learning described in vertebrates • temporal requirements of learning • differential conditioning • inhibitory learning • 2nd order conditioning • structures correlated with learning • mushroom bodies & antennal lobes • neurons correlated with learning • PE1 & VUMmx1