classical conditioning lecture 3

Question 1

basic cerebellar cortical circuitry

Answer 1

• mossy fibres excite granule cells,
• granule cells form parallel fibres
• parallel fibres excite purkinje cells
• purkinje cells inhibit cells in cerebellar nuclei

Question 2

mossy fibre input for the cs

Answer 2

convey info aout the tone CS to lobule HVI (frequency of firing increases with tone intensity)

Question 3

granule cells

Answer 3

mossy fibres synapse with grannule cells

• the axons of granule cells form parallel fibres that syapse with dendrites of purkinje cells
• there are many granule cells 8% of all neurons in brain.
• 100 per mossy fibre (expansion recoding)

Question 4

purkinje cells

Answer 4

cell bodies n the middle layer
sole output cells of cerebellar cortex
receives input from 150000 parallel fibre synapses.

Question 5

golgi cells

Answer 5

get input from parallel fibres
project back to the synapses between mossy fibres and granule cells
- are inhibitory so the more pf input the more they reduce - expansion recoding

Question 6

Stellate cells

Answer 6

inhibitory
input from pf
synapse with dendrites of PC
- balance excitatory drive from PF

Question 7

basket cells

Answer 7

inhibiotry
input from pf
snapse with cell body of pc
- balance excitatory drive from pf

Question 8

heiney et al 2014

Answer 8

stimulation of stellate and basket cells by optogenetics inhibited spontaneous firing of purkinje cells.

Question 9

simple spikes

Answer 9

Purkinje cells fire spontaneously - simple spikes

PF input increases rate from 50 to 200 per second.

Question 10

climbing fibre

Answer 10

US

• cell bodies in the inferior olive
• fire at low frequencies

Question 11

Effect on PC firing- complex spikes

Answer 11

Complex spikes produced by climbing fibre input

• very reliable whenever climbing fibre fires, PC also fires
• low frequency of firing compared with simple spikes- little effect on output

Question 12

Long term depression

Answer 12

CF input acts to alter the efficacy of parallel fibre synapses with purkinje cells.

Question 13

second candidate

Answer 13

deep cerebellar nuclei

• mossy fibre (CS) and climbing fibre (US) info also comes together at the interpositus nucleus.

Question 14

how can a role in NMR conditioning be related to general functions of the cerebellum

Answer 14

Cerebellar chip

• cerebellar modules: structure of cerebellar cortex is very uniform over its entire surface : different regions have different inputs and outputs but same basic organization.

Question 15

General function of the cerebellum

Answer 15

other parts of the brain issue movement commands, the cerebellum must ensure they are carried out properly

Question 16

Brindley (1964)

Answer 16

the purpose of the cerebllum is to learn motor skills so that when they have been learnt a simple or incomplete message from the cerebrum will suffice to provoke their execution

Question 17

general mossy fibre input

Answer 17

current state of the body

- current motor commands

Question 18

climbing fibre inputs- general

Answer 18

• sensory signals: touch pain visual inputs

- error signal/

Question 19

cerebellar zones

Answer 19

external wiring extremely diverse

- PC given strip recieves input from unique region of inferior olive.