1. In Vitro Analog of Operant Conditioning in Aplysia. I. Contingent Reinforcement Modifies the Functional Dynamics of an identified Neuron Interdisciplinary Program in Brain Science Eye Movement & Vision LAB. Hwang, Jae Won

2. Outline  Classical Conditioning vs Operant Conditioning  Feeding Behavior of Aplysia  In Vitro Analog of Operant Conditioning  Experimental Procedures  Yoked Control Procedure

3. Classical vs Operant  Classical Conditioning  Operant Conditioning USCS Organism UR Organism Response( Action) Reward Reinforcement System

4. Classical vs Operant(Cont ’ d)  Classical Conditioning : Learning about relations between stimuli  Operant Conditioning : Learning about the consequences of one ’ s own behavior Most learning situations inseparably comprise operant and classical components. So the analysis of operant conditioning is complicated.

5. Feeding Behavior of Aplysia  Biting occurs spontaneously as well as reflexively.  If food is present, biting leads to the ingestion of food through the buccal cavity. Aplysia Biting Food Reinforcement System

6. In Vitro Analog of OC  Isolated buccal ganglia preparation Biting → Tonic stimulation of the ventral branch of buccal nerve 2 (n.2,3) Food → Stimulation of the anterior branch of the esophageal nerve (E n.2) C-B conn. : Cerebrobuccal connectives E n. : Esophageal nerve I2 n. : Nerve to intrinsic buccal muscle 2 n. : Buccal nerve R n. : Radular nerve

7. In Vitro Analog of OC(Cont ’ d)  Tonic stimulation of n.2,3 elicits two different motor program. - Pattern I (ingestion-like pattern) : Neural activity associated with closure and retraction of the radula - Pattern II (egestion-like pattern) : Neural activity associated with closure and protraction of the radula

8. In Vitro Analog of OC(Cont ’ d)  Neuron B51 participates in the buccal pattern generator, and a postsynaptic follower motor neuron has been described as being active only during ingestion(Cropper et al., 1990). ☞ Thus, activity in B51 could participate in the genesis of pattern I and may contribute to the probabilistic occurrence of pattern I and the switching between this and other patterns.

9. Experimental Procedures  Determination of whether contingent stimulation of E n.2 on pattern I modified the dynamical activity of B51  Comparison of B51 activity in three groups of preparations 1. a contingent reinforcement group 2. a yoke-control group 3. a control group  Measurement of contingent-dependent change in burst threshold and input resistance

10. Experimental Proc.(Cont ’ d)  In all group of preparations, the neuronal activity was induced by monotonic(4Hz) stimulation of n.2,3.  The training lasted 10 min and began with the first occurrence of pattern I in the contingent-reinforcement preparation.

11. Yoked Control Procedure  A yoked-control procedure deprives one rat of sleep but forces both members of the pair to exercise an equal amount of time.