Outline of Lecture 48 (03-11 B; Linden)
Narrative summary of the lecture:
This lecture describes a model for how the cerebellum circuitry gives rise to conditioned learning.
The basic cerebellar circuit is shown in Figure 1—memorize it. It consists of the usual neuronal
components, but of added importance is the type of synapses. PF-PC, CF-PC, and MF-DCN synapses are
excitatory, whereas PC-DCN and CF-DCN synapses are inhibitory.
The cerebellar circuit can be seen as a negative feedback control loop for motor signaling through the
DCN. In the Marr/Albus model, a mechanism for associative eyeblink conditioning can be directly mapped
onto the cerebellar circuit:
- Parallel fibers carry the conditioned stimulus
- Climbing fibers carry the unconditioned stimulus
- Disinhibition of the DCN gives rise to the conditioned response
Since LTD of the PF-PC synapse via CF-PC association results in DCN disinhibition, the model proposes
that such LTD is the cause of eyeblink conditioni