Neural Exam 3 - Opening Questions

Most of the knowledge we have gained about the cerebral cortex comes from what sources?

People with some type of brain disorder/disease

Sensory information enters the cerebral cortex in which layer?

Layer 4 (IV) - Internal granular

Intracortical communication occurs in which two layers of the cerebral cortex?

Layers 2 (external granular) and 3 (external pyramidal)

Most information leaves the cerebral cortex from which layer?

Layer 7 (VII) - Multiform

The dorsal visual stream is highly involved in which fundamental motor skill that is performed multiple times on a daily basis?

Reaching and grasping

Which part of the premotor cortex, the dorsal or ventral, contains mirror neurons?

Ventral, Mirror neurons fire when we observe someone doing something (action observation)

Which part of the premotor cortex, the dorsal or ventral, helps encode the direction of reaching movements and integrates visual information with sensory information?

Dorsal

Which part of the cerebral cortex is more involved with higher level motor planning?

Pre-supplementary motor area

ALS is caused by damage to which part of the cerebral cortex (premotor, supplementary motor, or primary motor)?

Damage to the primary motor cortex

Which area of the brain responds to tactile information and joint movements (proprioception)?

Primary somatosensory cortex

Input into the cerebral cortex comes primarily from what three other locations in the brain?

Cerebellum, Thalamus, Basal Ganglia

Output from the cerebral cortex goes to the same three places listed above, plus what other two locations?

Red Nucleus, and reticular formation helps with locomotion

Convergence or divergence: Stimulating one or more cortical cells or neurons activates different groups of motor units and results in different movements.

Divergence

Convergence of divergence: stimulating different cortical cells activates the same groups of motor units and results in similar actions.

Convergence

What are the five pairs of nuclei that comprise the basal ganglia?

Caudate nucleus, putamen, substantia nigra, subthalamic nucleus, globus pallidus

What is the primary role of the direct pathway and the indirect pathway of the basal ganglia?

• Direct - initiate/facilitate movement (excitatory)

• Indirect - inhibitory effect, opposes competing motor plans/ unwanted movements

Which nuclei of the basal ganglia is affected by Parkinson’s disease? Is Parkinson’s a hyperkinetic or hypokinetic disorder?

Substantia nigra, hypokinetic disease, difficulty initiating movements

Which nuclei of the basal ganglia is affected by Huntingdon’s disease? Is Huntingdon’s a hyperkinetic or hypokinetic disorder?

Caudate nucleus and putamen (striatum), hyperkinetic disease, genetic disorder

What are some of the non-motor roles of the basal ganglia?

Helps regulate emotion, thinking, rewards (dopamine)

What is the central area of the cerebellum called?

Vermis

What is the ratio of inputs to outputs in the cerebellum?

40:1

What are the four common symptoms of a cerebellar disorder?

• Hypotonia - muscle weakness

• Astasia - loss of ability to maintain posture across multiple joints

• Abasia - loss of ability to maintain upright against gravity

• Ataxia - lack of coordination

What type of neuron or neurons bring information into the cerebellum?

Mossy and Climbing fibers

What type of neuron takes information out of the cerebellum?

Purkinje fibers

What are the possible functions of the cerebellum?

Helps with coordination, motor learning, error detection and correction, error based learning