Limbic System Flashcards
The basic components of the limbic system are?
Hippocampus Septal area Amygdala Prefrontal cortex Cingulate Gyrus Hypothalamus
What are the two functions of the limbic system?
To modulate functions of the hypothalamus or midbrain periaqueductal gray matter
Short term memory
Where does the limbic system receive information from?
- Sensory systems- One or more; directly or after processing in cortex
- Brainstem monoaminergic systems-dopamine, serotonin, norepinephrine, epinephrine, histamine, melatonin; this is the basis for mood change
Where do the limbic structures project to?
Hypothalamus, Midbrain PAG, somatic motor, ANS neurons of brain and cord»_space;For Modulation Can occur indirectly or directly
Feedback signals to cortex- provide emotional quality to sensory signals
The Papez Circuit explains the basic way ______ and _____ work.
2 way circiut for emotion Limbic and Cortex
memory storage
What are the components of the hippocampal formation
hippocampus, dentate gyrus, and subicular cortex
The output of the hippocampal formation goes through which structure?
Fornix > Septal area>Thalamus, mammillary bodies, hypothalamus, entorhinal, cingulate, preforontal cortex>contralateral hippocampus
What are the 4 functions of the hippocampal formation?
Attach emotional significance to snesory input
Modulate aggression
Modulate autonomic and endocrine functions
Learning and Memory
Where does the hippocampal formation receive input from?
- Entorhinal cortex with visual, auditory, and olfactory info
- Septal area
- Prefrontal cortex(9 and 10), anterior cingulate (32, 33), premammillary region
- Reticular formation (monoamine fibers) influencing mood
Where does information from the hippocamplal formation go to?
- Septal area
- Thalamus (anterior nucleus), mammillary bodies, hypothalamus; entorhinal, cingulate prefrontal cortex
- To contralateral hippocampus via commissure
How does info leave the hippocampal formation?
Fornix
What are the functions of the hippocampus?
4
- Attach emotional significance to sensory input
- Modulation of aggression
- Modulation of autonomic and endocrine functions
- Learning and memory
T/F The hippocampus is active during the acquisition of learning
True
Deficits in memory result from….. with the hippocampus
hippocampal input or output deficits
T/F The hippocampus is responsibile for spatial memory and for consolidation of memory from short term to long term memory
True
How long does short term memory last?
few minutes-few hours
Is subject to disruption and distortion
How long does long term memory last?
days, weeks, or much longer
Stable, self maintained
____ memory is alterations of existing synaptic connections and mechanisms of synaptic transmission
Short term memory
_____ mmemory requires multiple training trials
Long term
_____ memory does not require more permanent cellular changes such as gene transcription
Short term
_____ Requires synthesis of new proteins and changes are mediated by second messenger systmes
Long term memory
How can one improve his or her memory?
- Pay attention
- Organize
- Make connections
- Sharpen intelligent memory
- Have a plan
The nucleus accumbens is associated with which neurotransmitter and belongs in which area of the limbic system?
Norepinephrine
Septal area
Input to the septal area comes from
- Olfaction
- Monoaminergic brainstem systems
- Hippocampus
- Amygdala
- Lateral hypothalamus
Output from septal area goes to
- Hypothalamus (modulates hypothalamic function
- hippocampus via reciprocal connection
- anterior cingulate and prefrontal cortex
What are the functions of the septal area?
- aggression
- rage
- ANS functions
- rhythm generation for hippocampus
Where does the amygdala get input from?
- sensory systems, olfaction, taste, auditory
2. Cortex and prefrontal cortex
Where does info from the amygdala go?
- hypothalamus
- stria terminalis
- Periaquaductal gray area
What are the functions of the amygdala?
- Visceral processes of the hypothalamus
- Modulate aggression
- Organizing fear response
- modulation of feeding and drinking
- endocrine functions
Where does the prefrontal cortex receive info from?
- All regions of the cortex
- brainstem monoaminergic systems
- limbic structures and related structures
Where does prefrontal cortex limbic info do?
Executive function via direct projections to hypothalamus
and indirectly to the thalamus
Modulates everything
Where does input to the cingluate gyrus come from?
- anterior thalamic nucleus
2. ventral tegmental dopamine neurons
Where does cingluate gyrus info go to?
Dorsal medial nucleus of the thalamus
Hippocampus (subicular cortex)
Areas of the limbic system affected in Alzheimer’s are?
- Hippocampus
- Amygdala
- Parahippocampal gyrus
People with schizophrenia often have deficits in the prefrontal and temporal-hippocampal regions causing which kinds of impairments?
Verbal memory impairment
Declarative memory deficits
