1. Olfactory function The psychobiological approach to understanding basic biological systems Behavior Direct monitoring Comparative models Experience Manipulation pharmacology ablation genes

2. Learning mediated changes in behavior Learning is: A persistent change in behavior based upon experience Learning can be broken into two classes: 1. Non associative: Habituation Latent inhibition or CS pre exposure effect 2. Associative: Pavlovian or classical conditioning Instrumental or operant conditioning

3. Thompson and Spencer (1966) A negative relationship between response strength and number of trials. Spontaneous recovery of response strength following an extended intertrial interval. Recovery should be less than full. Interstimulus interval (ITI) affects rate of habituation. Short ITI produces rapid habituation, long ITI produces slow habituation. More intense stimuli produce greater response and slower habituation. Very intense stimuli produce an initial increase in response (sensitization) then habituate. Excessive habituation training produces subzero response. Habituation

4. Helothis virescens Facts Heliolithine moth larvae are serious agricultural pests causing hundreds of millions of dollars in agricultural damage annually. A method of behavioral control of this species is mating disruption. – The control of male reproductive behavior with synthetic female sex pheromones. While mating disruption strategies have been successfully deployed for many years, exactly how they work is not well understood.

5. Habituation of pheromone response in male H virescens

6. hexanal geraniol blank (air) 0.0 1.0 2.0 MEAN RESPONSE LEVEL TRIAL 1 5 10 20 15 25 HABITUATION TO ODORS IN Drosophila

7. CriteriaOperant ConditioningClassical Conditioning Type of Behavior Non-reflexive, voluntary behaviors Reflexive, involuntary behaviors Source of BehaviorEmitted by organism Elicited by stimulus Basis of Learning Associating a response and the consequence that follows it Associating two stimuli Responses Conditioned Active behaviors that lead to reinforcement Physiological and emotional responses Extinction Process Responding decreases with elimination of reinforcing consequences Conditioned response decreases when conditioned stimulus is repeatedly presented alone Associative conditioning: Operant vs classical

8. Pavlovian conditioning: distinguishing associative and non associative effects A. C. B. odor (CS) food (US) on off CS US CS US forward-paired and air-paired CS-US relationship backward-paired CS-US relationship random-paired CS-US relationship on -25sec +25sec 4 sec

9. Associative learning in the moth Manduca sexta Photo: W. Armstrong

10. Development of an olfactory-learning behavioral paradigm EMG electrode in feeding muscle exposed proboscis tip for sucrose application reference electrode odor blown across antennae.60.50.40.30.20.10 0 123456 Conditioning Trials Response probability N=80/group 2-hexanone 1-hexanol 1-decanol Time (sec) A. pre post 05 10 odor on 05 10 Before learning odor on 0510 After learning odor on 1-trial learning Moths learn most odors with interesting exceptions Once trained moths will respond to odor until they expire

11. Acquisition of conditioned response 312654.80.70.60.50.40.30.20 0.10 Geraniol Conditioning Trials Response probability forward pairing random pairing air forward pairing N=40/group

12. air- forward pairing TRIAL forward pairing backward pairing random pairing BEFORE TRIAL 1 BETWEEN TRIALS 5 & 6 AFTER TRIAL 10 CHANGE IN EMG SPIKE FREQUENCY (POST-PRE) 0 1 2 3 4 5 7 8 6 10 9 Test Trial (EMG Response) Only forward pairing produces a conditioned response *N=30 per group