Limbic system Flashcards
what are associated with the subcortical nuclei?
- amygdala
- hypothalamus
- septal nuclei
- anterior thalamic group
what are the 4 nerve fiber pathways?
- mamillothalamic tract
- fornix
- stria terminalis
- medial forebrain bundle
what are the connections of the complex loop?
- mamillary goes to anterior thalamic group via mamillothalamic tract
- aterior thalamic group to cingulate gyrus
- cingulate gyrus to para hippocampal gyrus
- parahippocampal gyrus to hippocampus
- hippocampus to mamillary bodies and septal region via the fornix
what are the 2 afferents ands where do they project to?
1-cortex - projects to all parts of the limbic lobe, amygdala and hypothalamus
2-reticular formation - projects to all parts of limbic lobe, amygdala, and hypothalamus
what are the 2 efferents of the limbic lobe?
- limbic lobe –> back to all parts of cortex by way of thalamic gating
- limbic lobe –> to the hypothalamus and RF
what are the 2 efferents of the amygdala?
- amygdala –> dorsomedial thalamic nucleus –> prefrontal cortex
- amygdala –> brainstem RF nuclei both directly and indirectly via Hypothalamus
what is the function of the limbic system?
generates behaviors necessary for the preservation of the individual and the species
-motivation, emotion, learning, memory
T/F: lesions of hippocampus and amygdala must be bilateral to result in MAJOR deficits of normal behavior.
However, unilateral stimulation
may result in abnormal behavior
T
what influence does limbic system have on hypothalamus and ANS?
powerful
what are the 4 main things the hippocampus is involved in?
- attention
- memory
- spatial orientation
- stress
T/F: the hippocampus must be bilaterally stimulated to result in alertness
F: both
what is the relationship between hippocampus and memory?
forms declarative, not procedural memory.
- also consolidation
what makes it possible for us to compare present spatial situations to experience?
Hippocampus has a cognitive mapping system which allows for this
what happens with stress and the anterior hypothalamus?
cortisol
what are 2 septal nuclei and what is notable about them?
- pleasure - sexual arousal/ euphoria
2. Rage - Bilateral lesions can lead to hyper excitability/ Rage
What is important about the amygdala with sensory-affective interactions?
Lesions result in what?
- instinctive reactions
- lesions produce inappropriate emotional responses to sensory stimuli
what is important about the amygdala with the emotional component to learning?
fear
how does the amygdala modulate hypothalamic activities?
stimulation can produce arousal, sexual activity, motor activity related to eating, aggressive behavior
What does lateral amygdala stimulation produce?
anger, overeating, pleasure, tameness
what does medial amygdala stimulation produce?
decrease aggressive behavior, sadness, fear
how is the connection of limbic system and hypothalamus displayed?
aggressive or defensive behaviors.
What behaviors are the medial amygdala/medial hypothalamus related to?
defense of self
What behaviors are lateral amygdala/lateral hypothalamus related to?
predatory or feeding behaviors
what area is more attuned to acting in satisfaction or pleasure?
anterior septal region
- euphoria and addictions of cocaine
