Olfactory function The psychobiological approach to understanding basic biological systems Behavior Direct monitoring Comparative models Experience Manipulation pharmacology ablation genes
Jan 13, 2016
Olfactoryfunction
The psychobiological approach to understanding basic biological systems
Behavior
Direct monitoring
Comparative models
Experience
Manipulation pharmacology ablation
genes
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
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
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.
MEAN ETHOGRAM SCORES FOR ALL THREE GROUPS
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
TRIAL
ETHOGRAM SCORE
6-2 Group
2-6 Group
6 Mix Only
CONTROLS
DAY 1DAY 2
DAY 3
DAY 4
Habituation of pheromone response in male H virescens
hexanal
geraniol
blank (air)
0.0
1.0
2.0
ME
AN
RE
SP
ON
SE
LE
VE
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TRIAL
1 5 10 2015 25
HABITUATION TO ODORS IN Drosophila
Criteria Operant Conditioning Classical Conditioning
Type of BehaviorNon-reflexive, voluntary behaviors
Reflexive, involuntary behaviors
Source of Behavior Emitted by organism Elicited by stimulus
Basis of LearningAssociating a response and the consequence that follows it
Associating two stimuli
Responses ConditionedActive behaviors that lead to reinforcement
Physiological and emotional responses
Extinction ProcessResponding decreases with elimination of reinforcing consequences
Conditioned response decreases when conditioned stimulus is repeatedly presented alone
Associative conditioning: Operant vs classical
Pavlovian conditioning: distinguishing associative and non associative effects
A.
C.
B.
odor (CS)
food (US)
on
on
off
off off
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
4 sec
4 sec
4 sec
Associative learning in the moth Manduca sexta
Photo: W. Armstrong
Development of an olfactory-learning behavioral paradigm
EMG electrode in feeding muscle
exposed proboscis tip for sucrose application
reference electrode
odor blown across antennae
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.40
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.10
01 2 3 4 5 6
Conditioning Trials
Res
pon s
e pr
o ba b
ili t
y
N=80/group
2-hexanone1-hexanol1-decanol
Time (sec) Time (sec)
A.pre post
0 5 10
odor on
0 5 10
Before learning
odor on
0 5 10
After learning
odor on
1-trial learning
Moths learn most odors with interesting exceptions
Once trained moths will respond to odor until they expire
Acquisition of conditioned response
31 2 654
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0
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Geraniol
Conditioning Trials
Res
pons
e pr
obab
ilit y
forward pairingrandom pairingair forward pairing
N=40/group
air- forward pairing
TRIAL
forward pairing
backward pairing
random pairing
BEFORETRIAL 1
BETWEENTRIALS 5 & 6
AFTERTRIAL 10
CH
AN
GE
IN E
MG
SP
IKE
FR
EQ
UE
NC
Y(P
OS
T-P
RE
)
-1
0
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9 Test Trial (EMG Response)
Only forward pairing produces a conditioned response
*N=30 per group