BN Unit 4

• What are the three types of muscles?

  skeletal, smooth, cardiac
• What neurotransmitter is used in the synapse of motor neurons?

  acetylcholine
• What brain area is activated during reflexive movements?

  None
• What is the motor cortex?

  area at the rear of the frontal lobes that controls voluntary movements
• What 3 brain areas make up the motor cortex?

  primary motor cortex, supplementary motor cortex, premotor cortex
• What brain areas modify output from the motor cortex?

  somatosensory cortex, posterior parietal cortex, basal ganglia, cerebellum, prefrontal cortex
• What is the function of the prefrontal cortex in motor output?

  Plans actions based on consequences by receiving information about target, external sensory information, and proprioception (where limbs are in space)
• What is the function of the premotor cortex?

  planning of movement using input from prefrontal cortex; It combines information needed for movement planning,

  such as the target being reached for and its location, which

  arm to use, and the arm's location.
• What is the function of the supplemental motor area?

  receives output from the prefrontal cortex to assemble sequences of movement such as playing the piano or eating
• What is the function of the primary motor cortex?

  Executes voluntary movements by organizing the activity of unspecialized cells; adds force and direction control. (DIRECT COMMAND)
• What is the function of the cerebellum in motor output?

  Maintains balance, refines movements, controls compensatory eye movements. Involved in learning motor skills. Also determines order of muscle contraction and precise timing
• What is the function of the basal ganglia in motor output?

  Uses information from secondary areas and somatosensory cortex to integrate and smooth movements; apparently involved in learning movement sequences.
• What is Parkinson's disease?

  Movement disorder caused by the death of cells that generate DOPAMINE in the basal ganglia and substantial nigra.
• Symptoms of Parkinson's disease

  tremors, rigidity of limbs, poor balance and difficulty initiating movements
• What side of the spinal cord do sensory neurons enter on?

  Touch and proprioception enter on the dorsal side. Pain and temperature information enter on the lateral side.
• Where does information from sensory neurons end up?

  somatosensory cortex
• What pathway does sensory information travel to end up in the somatosensory cortex?

  Spinal Cord -> Medulla Oblongata -> Midbrain -> Thalamus -> Somatosensory Cortex

  
• What is the pathway for motor OUTPUT?

  Motor Cortex -> Medulla -(contralateral cross)-> Ventral Spinal Cord -> Lower Motor Neuron -> Muscle that Needs to Move
• What is the dorsal root?


  collections of cell bodies outside the central nervous system which receive information from receptors in the skin
• Which area of the thalamus is associated with somatosensory system?

  ventral posterolateral nucleus (VPL)
• Where is the somatosensory cortex located? (REFRESHER)

  parietal lobe
• What does somatotopic arrangement mean?

  Specific areas of the somatosensory cortex receive specialized information
• Where is the motor cortex located?

  in the frontal lobe, on the anterior side (front) of the central sulcus
• motor map of primary motor cortex

  specific areas of PMC control different parts of the body
• What is the corticospinal tract?


  carries movement signals to spinal cord to cause movement
• What is the corticobulbar tract?

  carries signals to brainstem to move head, neck, and face
• upper motor neuron syndrome

  damage to motor neurons in frontal cortex, characterized by spastic paralysis
• lower motor neuron syndrome

  damage to neurons in ventral horn of spinal cord, results in flaccid paralysis
• What is the pathway for the knee jerk reaction reflex?

  spinal nerve -> dorsal root ganglion -> dorsal root -> dorsal horn -> ventral horn -> spinal nerve
• How is the basal ganglia similar to the limbic system?


  It is comprised of multiple brain areas, including the nucleus accumbens which is responsible for reward sensations.
• What neurotransmitters are involved in cognitive processing of motor commands?

  GABA (inhibitory) and dopamine (motivated movement, reward)
• What is classical conditioning?


  a type of learning in which one learns to link two or more stimuli and anticipate events

  
• How does classical conditioning effect future behavior?

  guide future responses to subconscious encoding of environmental cues
• Why do associations occur in classical conditioning?

  Sensory convergence in amygdala

  
  

  Ex. GETTING BIT BY SPIDER

  - > Imput of sensory neurons (pain signals) sent to amygdala

  - > Sensory input and fear response process simultaneously

  -> LTP occurs, strengthening association between spiders and fear response
• Hebb Rule (1949)


  if an axon of a presynaptic neuron is active while post-synaptic neurons are firing, synapse will strengthen
• long-term potentiation (LTP)


  increase in synaptic strength that occurs when pre- and post-synaptic neurons are active simultaneously, associated with learning;
• long-term depression (LTD)


  weakening of a synapse which occurs when stimulation of the pre-synaptic neuron is insufficient to activate the post-synaptic neuron; results in clearing out old memories to create storage for new ones
• associative long-term potentiation


  Strengthening of a weak synapse when it and a strong synapse on the same postsynaptic neuron are active simultaneously.
• How does long-term potentiation strengthen memory?

  If two neurons are frequently active at the same time, the connection between them gets stronger. This strengthened connection makes it easier for the neurons to communicate in the future. So, if you're learning something new, the neurons involved in that process become more efficient at sending signals to each other, which helps you remember the information better.
• Which neurotransmitter is necessary for activating long-term potentiation?

  glutamate