Cortex and Hippocampus Flashcards
Primary Cortex
- unimodal
- serves a single behavioral function
Secondary Cortex
- unimodal
- association for primary corticies
Tertiary Cortex
- heteomodal
- integrates info from secondary corticies
Quaternary Cortex
- heteromodal
- integrates info from tertiary cortices
Bottom Up Processing of Perception: Acetylcholine
- acetylcholine
- cholinergic populations in N. basalis and pedunculopontine tegmental nucleus
Bottom Up Processing: Norepinephrine
- noradrenergic cells of L. ceruleus have general functions which bear on aspects of attention, learning, and arousal
- activity probably improves processing of salient events in diverse forebrain sites
Dorsolateral Prefrontal Cortex (DLPFC) Damage
- unable to use intention (goals) to modulate attention (task at hand)
- failure to switch attention appropriately = perseveration
- undue requirement for environmental cues to accomplish task = environmental dependency
Anterior Cingulate and Motivation
- the apathy syndrome
- dec. goal directed behavior
- dec. goal directed cognition
- dec. emotional experience and responsiveness
- abulia= lack of will
- akinetic mutism
Orbitofrontal Cortex (VmOFC) Lesions
- impairment in ability to estimate the risk/reward associated with certain behaviors
- implies subconscious “gut feeling” about the implications of a given behavior
- implies suppression of behaviors felt to be excessively risky, esp. in social situations
Prefontal Cortex Function
- enhancement and inhibition of: sensory inputs, emotional control, motor control
- short term modulation: modulation of effective connectivity
- long term modulation: modulation of synaptic strengths
Hippocampus
- critical for episodic memory
- spatial memory, navigation, location
- associative networks
- integrates parallel streams of spatial and non spatial informtation: CA3
Hippocampus Schaeffer Collaterals
-CA3 -> CA1
Mossy Fibers
-dentate -> CA3
Perforant Path
-entorhinal -> dentate
CA3 Autoassociation
-CA3 -> CA3
Memory Consolidation
-reverse replay of sequences in the hippocampus during sleep
Layers 1-3 Cortex
- interoffice mail of cortex and outbox
- pyramidal cells
Layers 4.1-4.3 Cortex
- Inbox of cortex
- graule cells
Layers 5 and 6 of Cortex
-Pyramidal Cells
20% of cortical neurons are:
-inhibitory interneurons
Feedback Cortex Mechanism
- layers 2, 5, 6 -> lower layers 1, 5, 6
- top down
- predicted (habitual responses)
Feedforward Cortex Mechanism
- Layer 3 -> higher layer 4 -> 3
- bottom up
- observed responses to stimuli
