Class 5

Question 1

What is the Limbic System?

Answer 1

Group of brain structures that support variety of functions especially emotion. Among structures that may be included & whose functions greatly oversimplified in this umbrella term are -> Hypothalamus.

Question 2

What is Hypothalamus?

Answer 2

Maintains homeostasis by controlling ANS & endocrine system. HPA axis release cortisol in response to stress.

Question 3

What is the Hippocampus?

Answer 3

• Located deep in temporal lobe
• Key to consolidating memories during sleep especially episodic memories, learning & long term memory because it involves consolidating.
• Episodic memory involves recollection of particular life experiences. Memories are “filed away” in long-term storage in various areas of cerebral cortex.
• Memories are NOT stored in hippocampus for long
term. But it plays role in consolidating memories during
sleep.
• Sensory neuron is sensory processor that allows information from outside world to be sensed in form of chemical & physical stimulus
• Stored as short term memory and long term memory
• Memory is affected by many factors especially emotions. • Pain has been identified as physical condition that impairs memory & has been documented in chronic pain patients

Question 4

What does episodic memory involve?

Answer 4

Involves recollection of particular life experiences. These
memories are “filed away” in long-term storage in various areas of cerebral cortex. (memory for personal experiences)

Question 5

T/F Memories are stored in the hippocampus for the long term.

Answer 5

*False
• Memories are not stored in the hippocampus for the long
term.

Question 6

What is a sensory neuron?

Answer 6

Sensory processor that allows information from outside world to be sensed in form of chemical & physical stimulus
stored as short term memory & long term memory.

Question 7

Memory is affected by many factors especially emotions. Pain has been identified as what?

Answer 7

Physical condition that impairs memory & has been
documented in chronic pain patients

Question 8

What is Explicit Memory?

Answer 8

Conscious storage & recollection of data. Key brain
areas involved are cerebral cortex. Includes: semantic memory (form of long term memory that comprises person’s knowledge about the world).

Question 9

What is Implicit Memory?

Answer 9

Unconscious storage & recollection of information: it
includes

• Priming: process of subliminally arousing specific responses from memory. Implies that not all memory is consciously activated. In advertising for eg. priming is technique in which introduction of one stimulus influences how people respond to subsequent stimulus. Priming works by activating an association in memory just before another stimulus or task is introduced.

• Procedural memory: long term memory for skills involved in particular tasks for example walking. Often, start to form early in life, you do not need to be consciously aware about how to perform these motor skills. Key brain areas involved in procedural memory are basal ganglia & cerebellum which are considered unconscious motor centres

Question 10

What is Priming?

Answer 10

Process of subliminally arousing specific responses from memory. Implies that not all memory is consciously activated. In advertising for eg. priming is technique in which introduction of one stimulus influences how people respond to subsequent stimulus. Priming works by activating an association in memory just before another stimulus or task is introduced.

Question 11

What is Procedural Memory?

Answer 11

Long term memory for skills involved in particular tasks for example walking. Often, start to form early in life, you do not need to be consciously aware about how to perform these motor skills. Key brain areas involved in procedural memory are basal ganglia & cerebellum which are considered unconscious motor centres

Question 12

What is Synaptic Plasticity?

Answer 12

• Ability of synapses to strengthen or weaken over time in response to increases or decreases in their activity.

• Long-lasting changes in efficacy of synaptic connections is called long-term potentiation (LTP).

• The two hippocampi use LTP in transformation of information, from short-term memory to long-term memory. (LTP often requires fair bit of repetition if weird neurospeak words are going to stick in one’s brain).

Question 13

What is long-term potentiation (LTP)?

Answer 13

Long-lasting changes in efficacy of synaptic connections

Question 14

What is the Amygdala?

Answer 14

• Regulates emotional reactions such as happiness, fear, anger, & anxiety. Memories with strong emotional components are more likely to be remembered than ones with less emotional content. Eg. ‘fear learning.’ (Fearful memories can be created in as little as one incident, leading to avoidance of specific fearful stimuli.)

Question 15

Damage to Amygdala can lead to?

Answer 15

• Increased aggression, irritation, emotional loss of control, & difficulties regulating emotions, particularly fear. Autism, depression, posttramatic stress disorder, & bipolar illness have all been linked to abnormalities in amygdala.

Question 16

What is Nucleus Accumbens?

Answer 16

• Brain’s so-called pleasure center, plays role in sexual arousal & “high” derived from any sort of “addiction”.

• Limbic system is contained in forebrain. There are
conflicting viewpoints on which structures should be included in the system.

• The extremely small bilateral hypothalamus is one central elements of limbic system. Basic function is homeostasis. Combines information from many other areas of brain, it’s receptive to many stimuli including light, odour, stress, & arousal in order to govern these numerous processes via ANS & endocrine system

Question 17

What does the Limbic System have to do with Smell?

Answer 17

• Although olfaction is generally assumed to play minor role in humans compared to vision or audition, it’s also accepted that odours have rather unique status for eliciting memories.

• Smells are handled by cranial nerve 1, which sends information to brain for further processing. Odours take direct route to limbic system, including amygdala & hippocampus, regions related to emotion & memory.

Question 18

What is the Basal Ganglia?

Answer 18

• Collection of nuclei deep to grey matter of cerebral cortex.

• Even though ganglion refers to PNS, it’s still called basal ganglia for historical reasons, even though it should technically be called basal nuclei.

Question 19

The Basal Ganglia generally help in?

Answer 19

• Directing involuntary movements including postural
proximal adjustments. This “background positioning” is necessary before fine, distal movements may take place. Disorders vary depending on which structures are affected. Deficits tend to fall into one of two categories.

• Hyperkinesia: presence of abnormal involuntary movements and/or excessive movements.
• Hypokinesia: absence, reduction or difficulty with intended, voluntary movements.

Question 20

What is Hyperkinesia?

Answer 20

The presence of abnormal involuntary movements and/or
excessive movements.

Question 21

What is Hypokinesia?

Answer 21

Absence, reduction or difficulty with intended, voluntary movements.

Question 22

T/F The overall effect of the Basal Ganglia is inhibitory?

Answer 22

• True
  • Overall effect of the BG is inhibitory.
  • To sit still, you inhibit all movements except those reflexes that maintain upright posture. To move, you dampen certain postural reflexes, & release brake on
  voluntary movement.
  • Dysfunctions often involve disinhibition of cerebral structures that are normally inhibited by basal ganglia. Even small disturbances can throw whole motor system off.

Question 23

T/F Dysfunctions often involve disinhibition of cerebral structures that are normally inhibited by basal ganglia?

Answer 23

• True
  • Dysfunctions often involve disinhibition of cerebral structures that are normally inhibited by basal ganglia. Even small disturbances can throw whole motor system off.

Question 24

What is Tourette Syndrome?

Answer 24

• Disorder characterized by tics. Tics are recurrent involuntary movements or sounds. Tics can be classified as simple or complex. Simple tics involve only one group of muscles & might consist of actions like eye blinking or throat clearing. Complex tics are more elaborate & might involve actions like reaching out to touch something or someone.

• Torette’s is famous for involuntary use of obscene language (coprolalia) which occurs in less than 20 percent of cases. Basal ganglia are especially relevant to tourettes syndrome for their role in modulating motor movements & suppressing unwanted actions

• Faulty basal ganglia inhibitory mechanisms may fail to stop action person might prefer to suppress forming basis of tics. Failed inhibition is thought to be coupled with increased activity in motor pathways that generate movement

Question 25

What is coprolalia?

Answer 25

• Torette’s is famous for involuntary use of obscene language (coprolalia)

Question 26

What is Parkinson's Disease (PD)?

Answer 26

• Most common disorder of BG & 2nd most common neurological disorder after Alzheimer’s disease. Results from loss of dopaminergic neurons in substantia nigra of brain stem. PD presents very differently in different people, most primary symptoms have to do with movement problems. • In early stages, hypomimia (reduction in expressiveness of face) is often present. Arms may not swing when walking. Speech may become soft or slurred • PD symptoms worsen as disease progresses over time. Onset is typically around 60 years of age. Experimental studies suggest that symptoms do not appear until nearly all dopaminergic neurons have been lost. This explains late onset of symptoms. • Although individuals can be "diseased" for years. Resting tremor is present in most PD patients. Tremor is involuntary, rhythmic, twitching movement. Most common of all involuntary movements, can affect the hands, arms, eyes, face, head, vocal folds, trunk, & legs. Most PD tremors occur in hands. Often first noticeable symptoms of PD. Typically stops upon voluntary movement of part,& intensified by stimuli such as cold, fatigue, & strong emotions.

Question 27

What is the Cerebellum?

Answer 27

• Located below occipital lobes of cerebrum & posterior to brainstem. Functions as important centre for coordination of movements & maintenance of balance. • Constantly receives information from proprioceptors. Makes adjustments so that planned movements initiated from motor cortex are successful. Has extensive connections with both vestibular apparatus and eyes. Plays significant role in maintenance of equilibrium. Unlike cerebrum, which works on contralateral basis, cerebellum works ipsilaterally. Dysfunction can be due to many causes, such as tumors, trauma, infection, infarction, & metabolic problems, (i.e., toxic effects of alcoholism).

Question 28

What is Ataxia?

Answer 28

Inability to coordinate muscles usually most prominent during gait. Ataxic gait aka “drunken sailor’s gait” unsteady, staggering gait.

Question 29

What is Intention Tremor?

Answer 29

Amplitude of an intention tremor increases as extremity approaches endpoint of deliberate & visually guided movement. When experiencing an intention tremor, one often overshoots or undershoots their target, condition known as dysmetria (inability to perform accurate movements due to over or under projection).

Question 30

What is decomposition of movement?

Answer 30

Movements are broken into simpler component pieces that must be done slowly with much concentration rather than a smooth coordinated movement.

Question 31

What is Dysmetria?

Answer 31

Often occurs with an intention tremor; defined as inability to perform accurate movements due to over or under projection

Question 32

What is hypomimia?

Answer 32

Reduction in expressiveness of face

Question 33

What is a Resting tremor?

Answer 33

• Present in most PD patients. Tremor is involuntary, rhythmic, twitching movement. Most common of all involuntary movements, can affect the hands, arms, eyes, face, head, vocal folds, trunk, & legs. Most PD tremors occur in hands. Often first noticeable symptoms of PD. Typically stops upon voluntary movement of part,& intensified by stimuli such as cold, fatigue, & strong emotions.