Exam Three - Limbic System Flashcards
what does the limbic system do?
controls emotions and feelings
what 4 main things make up the limbic system
1 - cingulate gyrus (emotions)
2 - amygdala (emotions and memory)
3 - hippocampus (learning and memory)
4 - anterior thalamus
cingulate gyrus function
plays role in emotion
hippocampus function
involved in learning and memory
amygdala function
involved in emotions and memory
cannon-bard theory
the proposition that emotion and physiological reactions occur simultaneously
when transection the forebrain only in cats what happened
sham rage
sham rage
a violent reaction to normally innocuous stimuli following removal of the cerebral cortices
when the posterior hypothalamus was separated from the brain stem what happened
there was no coordinated rage response
what did the sham rage studies show
the hypothalamus plays a large role in coordinating emotional behavior
what happens when the lateral hypothalamus is stimulated
anger
papez circuit
a limbic based circuit that was once though to constitute a largely undifferentiated “emotional” brain
- involved the hypothalamus with mamillary bodies, anterior thalamic nucleus, cingulate gyrus, and hippocampus
papez circuit pathway
hippocampus -> fornix -> mammillary bodies -> mammillary thalamic tract -> anterior thalamic nuclei -> cingulate gyrus
triune brain theory
dividing brain regions into evolutionary age
1 - primitive reptilian
2 - limbic/mammalian
3 - neocortex
brain one (R complex)
- contains brainstem, pons, cerebellum, mesencephalon, basal nuclei and olfactory bulbs
- housekeeping brain
- concerned with basics such as hunger, temp control, fight or flight, territory, safety
brain 2
- limbic system forms brain we share with mammals
- registers reward/punishment, seat of emotion, controls autonomic nervous system
brain 3
- “thinking cap”
- allows for complex social interactions and advanced planning
microstimulation of the amygdala produces feelings of
fear and rage
urbach-wiethe disease
a disease in which the amygdala and adjacent areas are destroyed, it leads to the impairment of emotional processing and memory for emotional material impaired learning of how to discern emotions in facial expression
the amygdala is close to the hippocampus in this lobe
temporal
3 neuron groups of the amygdala
1 - central
2 - medial
3 - basolateral
this receives input from the sensory cortex of all modalities
basolateral nuclei
this is the major output of the amygdala and is involved in autonomic components of emotions
central nuclei
this plays a key role in innate emotional behaviors by relaying olfactory info to the hypothalamic nuclei involved in reproduction and defense
medial nuclei
amygdala stimulation produces emotional behaviors through ___ pathways
subcortical
stimulation of this structure can act as a reinforcer
hypothalamus
these are midbrain dopaminergic neurons that form most of the mesolimbic and mesocortical projections involved in reward
ventral tegmental area
what is the most effective site for stimulation? it activates the VTA indirectly
medial forebrain bundle
cocain, amphetamines, and nicotine increase _____ release in the brain especially the nucleus accumbens
dopamine
this is the smallest part of the cerebral hemispheres and is located in basal medial part of the temporal lobe
hippocampus
what does the hippocampus do
learning and memory
converts short term memory to long term memory
scoville did a bilateral medial temporal lobe resection on a patient. what happened to the patien
he had sever anterograde impairment
retrograde amnesia
an inability to retrieve info from one’s past
anterograde amnesia
an inability to form new memories
episodic memory
personal experiences and facts
semantic knowledge
general knowledge
autonoetic consciousness
the human ability to mentally place ourselves in the past, in the future, or in couterfactual situations, and to thus be able to examine our own thought, our sense of self affects our behavior, in the present past and future
autobiographical memory
the memory for events and facts related to one’s personal life story
perceptual memory
long term memory for auditory, visual, and other perceptual info
this type of memory is important for reasoning and the guidance of decision making and behavior
working memory
declarative memory
it refers to memories which can be consciously recalled such as facts and events
what happens in advanced alzheimers
destruction of neurons and neural connections in the cerebral cortex and significant loss of brain mass
senile plaques
extracellular aggregates of amyloid peptide
people with alzheimer’s disease have an excessive number of such plaques
neurofibrillary tangles
bundles of abnormal filaments within neurons
where does someone with AD have neuronal loss
hippocampus, frontal, parietal and anterior temporal cortices, amygdala
neurotransmitter and neuropeptide deficits in AD
Neuropeptide Y
somatostatin
ACh
substance p
corticotropin releasing factor
t or f: people with down syndrome that live beyond 35 have an increased risk for developing AD
t
a progressive neuronal degeneration in the neocortex of the frontal and anterior temporal lobes
frontotemporal dementia
3 neurodegenerative disorders that can affect memory
1 - frontotemporal dementia
2 - huntingtons
3 - parkinsons
chronic alcoholism and nutritional and B! deficiency can lead to
anterograde amnesia
anterograde amnesia is characterized by damage to ________-
- mammillary bodies
- medial dorsal nucleus of the thalamus
