1. Introduction to Neurobiology Lecture 13: Classical conditioning 1 Inhibitory Cerebello-Olivary Projections and Blocking Effect in Classical Conditioning. Kim et al Science (1998) Role of Olivary Electrical Coupling in Cerebellar Motor Learning. Van Der Giessen, et al Neuron (2008) Cerebellar LTD and Learning-Dependent Timing of Conditioned Eyelid Responses. Koekkoek, et al 2003

2. Associative Learning Nonassociative Habituation Sensitization A single type of stimulusThe relationship between two stimuli or reward. Classical conditioning Operant conditioning Extinction Blocking Reinforcement Punishment

3. Definitions An Unconditioned stimulus (US) is a stimulus which “naturally” elicits an (unconditioned) response (UR). For example: An airpuff to the eye is an unconditioned stimulus which elicits an eyeblink (nictitating membrane response). A conditioned stimulus (CS) is a “neutral” stimulus (e.g. a tone), which, by being associated with the US, leads after learning to a conditioned response (CR).

4. Basic paradigm Before learning,US UR CS nothing Training:CS+US UR CS increasing CR(=UR) Post-training:CS CR (=UR). Temporal relationship: 1) Simultaneous 2) Delayed (partial overlap in time) 3) Trace (separated in time. Usually 200ms-2s.

5. The nictitating membrane response

6. Circuitry for conditioning nictitating membrane response

7. The suppression of CF during learning of eye blink. Naive animal Trained animal

8. US only CS-US With PTX GABA is involved in the suppression of CF.

9. Extinction protocol with: no infusion ACSF PTX GABA is involved in the extinction of CR.

10. The response of trained animal to tone + puff test sessions with: ACSF NBQX (AMPA receptor antagonist) AMPA receptors are involved in the extinction of CR.

11. Blocking: CS “A” is tone; CS “B” is light; US is air puff. The eyeblink response to air puff is the UR The Eyeblink response to A or B is the CR B+US CRB A+B+US CRA/B A+USA+B+US CRA B // CRA A+US Blocking of conditioned eyelid responses

12. Phase I, animals received seven daily sessions of tone-airpuff conditioning; Phase II, animals underwent five sessions of tone-light-airpuff compound conditioning. Either picrotoxin (PTX) or (ACSF) was infused directly into the inferior olive. Controls experienced only the second phase of the blocking procedure. Afterward, all animals were presented with light-airpuff pairings to assess whether conditioning to the light had accrued during compound conditioning (phase II). Both control and PTX animals exhibited significant learning to the light CS compared with the ACSF animals - blocking did not occur in the PTX group. PTX had no effect on the performance of CRs and URs during the compound conditioning, indicating that PTX selectively affected blocking. ACSF PTX CONTROL Phase 1 phase 2 phase 3 Blocking GABA is involved in blocking of conditioned eyelid responses

13. olivepons PFCF PC’s LTD DCN CR Blocking: US inhibition USCS PTX: blocks inhibition prevents blocking prevents extinction Extinction: without US or with NBQX

14. Eyeblink response in L7-PKCi mutants Learning in mutant lines

15. Timing problems in L7-PKCi mutants

16. Timing in L7-PKCi mutants is independent of the CS-US interval

17. Lesion of the cerebellar nuclei disrupt timing and amplitude of the response

18. Timing in the Cx 36 -/- mutants

19. The VOR gain change and conditioning eyeblink

22. Blocking neuronal activity in cerebellar output Superior cerebellar peduncle blocked using perfusion of TTX Expression of eyeblink conditioning blocked, but not acquisition Krupa and Thompson, PNAS 1995

23. The cerebellar-olivary system LTD LTP 1.2Hz<>Rate

25. phase 1 : seven daily sessions of tone-airpuff conditioning. phase 2 : five sessions of tone-light-airpuff compound conditioning while either PTX or ACSF was infused. phase 3 : all animals were presented with light-airpuff pairing tests. controls experienced only the second phase of the blocking procedure. Blocking of conditioned eyelid responses

26. The daily training consisted of 10 blocks of 10 trials. The trials were separated by a random intervals (20to 40 ms). The trials were separated by a random intervals (20 to 40 ms). Response of wild-type (wt) after 2 days and after 4 days. CR- conditioned response UR- unconditioned response

27. Circuitry for conditioning nictitating membrane response

28. Wild-type: Conditioned responses (%)- 80 Average peak amplitude- 0.68 Average peak velocity- 32.6 mm/s LTD-deficient mice: Conditioned responses (%)- 30 Average peak amplitude- 0.44 Average peak velocity- 19.6 mm/s

29. Average CS-alone responses when the ISI is extended to 500 ms If the timing is LTD- dependent, the amplitude and velocity in the L7-PKCi mutant should not be influenced by the length of the ISI. indeed, the mutants ’ peak amplitude and peak velocity weren ’ t changed. In contrast, those wt values were changed. Blue- wild type Red- mutants

30. Red - pre-lesion Blue – post-lesion Green - post-sham lesion Mutants wt (After T-4) Conditioned responses still occur after lesions of the cerebellum in both mutants and wt, but the amplitudes were significantly reduced. Lesion of the cerebellar nuclei disrupt timing and amplitude of the response