11 - Cerebellum

How are different cell types of cerebellum connected?

*mossy fibers* (+) bifurcate into parallel fibers, which contact 100s of Purkinje cells 1 *climbing fiber* (+) synapses on many dendrites of 10 Purkinje cells Purkinje cell (-) is output, inhibits deep cerebellar nuclei

A patient with left cerebellar damage would most likely exhibit which symptom? A) Jerky, imprecise movements on the left side of the body B) The inability to stop a movement (hyperkinetic) on the left side of the body C) Jerky, imprecise movements on the right side of the body D) The inability to stop a movement (hyperkinetic) on the right side of the body

A) Jerky, imprecise movements on the left side of the body

Which is a major function of the cerebellum? A) Alter local circuits of the brainstem and spinal cord via direct projections to the lower motor neurons B) Analyze errors between intended motor output and actual motor output C) Modulate the output of the basal ganglia D) Relay information from the primary somatosensory cortex to the primary motor cortex

B) Analyze errors between intended motor output and actual motor output

Which type of cell provides the only output from the cerebellar cortex? A) Granular cells B) Purkinje cells C) Climbing fibers D) Mossy fibers

B) Purkinje cells

Mossy fibers synapse on A) Purkinje cells and deep cerebellar nuclei. B) Purkinje cells and granule cells. C) granule cells D) deep cerebellar and pontine nuclei.

C) granule cells

The axons from the pontine nuclei into the cerebellum are referred to as _______ fibers. A) parallel B) basket C) mossy C) stellate

C) mossy

Which of the following is a characteristic of Purkinje cells that allows for the high level of convergence and divergence from the granule cells? A) Cell body located in the Purkinje cell layer B) An elaborate dendritic tree that extends in parallel with the parallel fibers C) Receiving of numerous synaptic contacts from climbing fibers D) An elaborate dendritic tree that extends perpendicularly to the parallel fibers

D) An elaborate dendritic tree that extends perpendicularly to the parallel fibers

Which synaptic connection would be most affected by the presence of a GABA antagonist in the cerebellum? A) Mossy fiber input onto deep cerebellar nuclear cells B) Parallel fiber input onto Purkinje cells C) Climbing fiber input onto Purkinje cells D) Purkinje cell input onto deep cerebellar nuclear cells

D) Purkinje cell input onto deep cerebellar nuclear cells

Which cerebellar neurons are principal output neurons of cerebellar cortex and which cell types are outputs of cerebellum?

Purkinje cell = only output of cerebellar cortex deep nuclei = output nuclei of cerebellum

Which cell types in cerebellum are inhibitory?

Purkinje cells - inhibit deep cerebellar nuclei

Describe activity of Purkinje cells and deep cerebellar nuclei cells during movement

at rest, Purkinje cells and deep cerebellar nuclei have tonic activity during movement, they change frequency of firing - comes in waves

How does cerebellar ataxia differ from features of Parkinson's or Huntington's disease?

cerebellar ataxia results in jerky movements but people can still initiate them (?), whereas Parkinson's and Huntington's have rigidity and

What is cerebellar ataxia?

cerebellar damage that results in decomposed, jerky movements, due to inability of cerebellum to correct ongoing movements on the same side as site of damage

What cell types are found in the cerebellum? (5)

mossy fibers (input from pons) climbing fibers (input from medulla) granule cells (interneurons) basket cells (interneurons) Purkinje cells (output)

Which cell types in cerebellum are excitatory?

mossy fibers, climbing fibers