Learning & Memory - Cerebellum Pt. 1

Front 1

Motor learning in the cerebellum serves as what type of paradigm

Back 1

Classical conditioning

Front 2

Motor learning requires what type of motor movements?

Back 2

Well-timed and coordinated

Front 3

Pavlovian conditioning of motor responses can serve as what type of model?

Back 3

How the brain acquires new motor responses. (Eyeblink conditioning as a model)

Front 4

Eyeblink conditioning

Back 4

Pair CS - tone or light - with US - puff of air into eye. The UR is eyelid closure or nictitating membrane extension in some animals. Can be done by delayed or trace conditioning - subject learns exact timing of CR.

Front 5

Hippocampus and Eyeblink conditioning

Back 5

CR monitored by viewing neuronal activity in CA1 pyramidal cells - show that neuronal activity precedes eyeblinking behavior.

Front 6

Hippocamal lesions - effect on learned CR's

Back 6

Do not affect acquisition or retention of CRs after delayed conditioning, but do disrupt retention of CRs in trace conditioning. Suggests hippocampus is necessary for trace conditioning. However, after 1 month lesions have no affect on retention.

Front 7

What is unique about trace conditioning?

Back 7

It requires consciousness - must be aware that there is a CS and a US in order for learning to occur.

Front 8

CR's and cerebellar activity

Back 8

CR neuronal activity shown in the dentate and interpositus nucleus. Furthermore, lesions of the cerebellum show inability to learn CR's but maintains UCRs.

Front 9

Cerebellar anatomy - important structures

Back 9

Contains Purjinke cells which are the most dendritic cells in the brain. Many neuronal inputs pass across these dendrites, while a solo climbing fiber for each Purjinke cell mediates excitation. If the inputs to the Purjinke cell are insuitable, the CF causes LTD.

Front 10

Anatomy of a learning circuit

Back 10

Sensory input - pathways that convey information about CS and US; loci of association - neurons where information about CS and US converge; Motor output - pathways that initiate behavioral responses

Front 11

Sensory Input - TONE CS Pathway

Back 11

Conveyed by pontine mossy fibers. Auditory information goes through 8th cranial nerve (cochlear nerve) to the pons. Pons projects to deep nucle and cortex. A pontine lesion blocks conditioning to a auditory CS

Front 12

Middle cerebellar peduncle lesions and the auditory pathways

Back 12

Prevents acquisition and abolish retention of CR, but not US nor UR. You can electrically stimulate the MCP to produce a CR.

Front 13

Sensory Input - Airpuff US Pathway

Back 13

Conveyed by inferior olive climbing fibers. Inferior olive receives input from trigeminal nucleus. IO projects to deep nucleih and cortex. IO lesions will prevent CR acquisition but does not affect UR.

Front 14

Inferior olive stimulation and airpuff US pathway

Back 14

Produces behavioral responses - this means you can create learning via stimulating this site. However, a negative feedback system occurs over time where spikes from US decrease (similar to Rescola-Wagner model in that learning gets smaller and smaller)

Front 15

IO lesions and CR extinction

Back 15

IO lesions made after conditioned training cause gradual extinction of the CR despite continued training.

Front 16

CS-US association

Back 16

Mossy fibers carrying CS and Climbing FIbers carrying US converge in the cerebellum -- the locus of memory

Front 17

Motor Output - UR Pathway

Back 17

A loop directly from the trigeminal nucelus of the face to the facial nucleus of the eye to cause the UR of eyeblinking.

Front 18

Motor Output - CR Pathway

Back 18

Conveyed by red nucleus projection to cranial motor nuclei. Red nucleus projects to facial nucleus, causes CR. A red nucleus lesion impairs performance of learned responses.

Front 19

Superior cerebellar peduncle lesions (as well as red nucleus lesions)

Back 19

Abolishes both acquisition and retention of CRs but do not affect URs. Stimulation of the red nucleus is not a sufficient US.

Front 20

CR Pathway - Negative feedback

Back 20

CR pathway can inhibit the US pathway via an inhibitory projection form the deep nucleus that turns off the inferior olive - accounts for less learning after a given period of time.