NEURO: Emotion Flashcards
What is emotion?
Emotion is a strong feeling deriving from one’s circumstances, mood, or relationships with others.
How was it found that there was an increase of anxiety-like behaviour following long-term opioid abstinence?
The elevated-plus maze test measures the conflict between the natural tendency of mice to explore a novel environment versus the tendency to avoid exposed areas.
The animals were positioned in the centre of the apparatus and left to explore for 5 mins. Anxiety-like behaviour was determined by calculating the amount of time spent and the number of entries each mouse made in the open and closed arms.
Morphine withdrawn animals spent significantly less time and entries in the open arms compared to saline withdrawn animals.
These data clearly show that prolonged withdrawal from morphine induces anxiety-like behaviour, which is consistent in humans.
How does morphine abstinence affect social interaction?
It was concluded that morphine withdrawal induced social interaction deficits in mice which is in agreement with the situation of opioid abstinent humans.
This was concluded based on tests on how long mice spent with unfamiliar mice.
What are the two theories of emotion?
JAMES-LANGE:
This claims that we experience emotions in response to physiological changes in our body.
CANNON-BARD:
This claims that we can experience emotions independently of emotional expression (dissociations).
The emotions are produced when signals reach the thalamus, either directly from sensory receptors or by descending cortical input.
Explain the difference between the James-Lange and the Cannon-Bard theory of emotion.
The James-Lange theory: emotion experienced in response to physiological changes in body
The Cannon-Bard theory: emotions occur independent of emotional expression—no correlation with physiological state
So, with the James-Lange theory, you express, and thus you feel.
With the Cannon-Bard theory, you feel, and thus you express.
What is the brain system responsible for emotions?
We have Broca’s limbic lobe. Limbus (latin) means border. It is a group of primitive cortical gyri that form a ring around the brain stem.
Broca’s limbic lobe includes:
- the parahippocampal gyrus
- the cingulate gyrus
- the subcallosal gyrus
What is the papez circuit?
It’s a group of limbic structures, including cortex, involved in emotion.
It’s an emotional system on the medial wall of the brain linking the cortex with the hypothalamus.
The cortex is critical for emotional experience.
The hippocampus governs behavioural expression of emotion (the rabies infection implicates hippocampus in emotion: hyper-emotional responses).
Anterior thalamus lesions lead to spontaneous laughing or crying.
Evolution of limbic system allows animals to experience and express emotions beyond stereotyped brain stem behaviours.
What constitutes the limbic system (as we define it)?
- cingulate gyrus
- parahippocampal structures
- septal nuclei
- amygdala
- enthorinal cortex
- hippocampal complex:
- dentate gyrus
- CA1-CA4 subfields
- subiculum
What are some general functions of the limbic system?
Anatomically, the limbic system appears to have a role in attaching a behavioural significance and response to a stimulus, especially with respect to its emotional content
Damage to the limbic system leads to profound effects on the emotional responsiveness of the animal.
What are the functions of the cingulate gyrus?
- has a role in complex motor control
- pain perception
- social interactions-mood
What are the functions of the hippocampus proper and parahippocampal areas?
- primary function in memory
What are the functions of the amygdala?
- involved in learning and storage of emotional aspects of experience
Why are there difficulties with the single emotion system?
There are difficulties due to the diversity of emotions and brain activity.
There are many structures involved in emotion, so there is no one-to-one relationship between structure and function.
Describe the amygdala’s structure and connections.
It receives input from the neocortex:
- all lobes, including hippocampal, and cingulate gyri
It’s also connected to the basolateral nuclei, and receives information from all sensory systems.
It’s also connected to the corticomedial nuclei and the central nuclei.
Output to hypothalamus (region involved in expression of emotion)
Stria terminalis
Ventral amygdalofugal pathway
What happens if we remove the temporal lobe?
Temporal lobe removal includes removing the temporal cortex, amygdala, and the hippocampus.
It resulted in:
- psychic blindness
- oral tendencies
- emotional changes (reduced fear)
- altered sexual behaviour
