Block 3- Parietal, Temporal, amygdala Flashcards
DORSAL/where stream functions
Spatial awareness
Motion detection/visual guidance
Spatial/cognitive function, emotion
Representation of peripheral visual field
Middle temporal
Linear motion.
Middle superior temporal
Radial dynamic motion, different directions.
Injury to MT results in
Loss of motor perception
Attention
State if selectively processing simultaneous sources of Info (focus on one)
Posterior parietal Cortex
Spatial awareness
Parietal: Left vs. Right
Right: spatial
Left: Wernicke’s (language processing)
Superior parietal
Superior somatosensory cortex
Tactile info, control of action
Area 5 is visuospatial Attention.
Inferior parietal
Polymodal info. Visuospatial Cognition (area 7)
Superior and inferior parietal are separated by
Intraparietal sulcus
Has cells important for processing spatial attention
Ventral stream Functions
Blob/interblob striate
Shape, color perception
Object/face recognition (IT areas)
Visual patterns
Lateral intraparietal area
Spatial attention. (lateral sulcus)
Responses enhanced by attention. If looking at cue, firing increases to enhance processing.
Ventral intraparietal area
Visual, auditory, and somatosensory areas brought together (polymodal)
Taste/olfaction too
Parietal injury
Parietal cortex lesions can have different frames of reference
Egocentric: self/objects
Allocentric: objects/objects
Parietal bilateral lesions
Simultanagnosia
Inability to see multiple objects at once
Posterior parietal cortex (PPC) lesion, component of Balient’s
Optic Ataxia
Impairment of visually guided teaching
Affect hemisphere generally opposite lesion.
Inability to use visuospatial info to guide limb movements
Lesion to parietal lobe (usually right)
Hemispatial neglect
Failure to notice objects in hemifield contralateral to lesion
Failure of cortical processing.
Draw a clock picture
Dorsal pathway (3 steps)
polymodal neocortical
Parahippocampal/posthirinal (spatial cognition)
Hippocampus (medial entorhinal area) –> Spatial grid cells.
Prefrontal cortex
Ventral pathway 3 steps
Unimodal neocortical
Parahippocampus/Perirhinal cortex
Hippocampus (Lateral Entrohinal area) –> Olfactory/somatosensory
Prefrontal cortex
Goes to CA3, then to CA1
LTD (decrease synaptic efficacy) and LTP take place in
Hippocampus, important for memory.
Working/short term memory (<1 min) is located…
Prefrontal cortex
Explicit memory (autobiographical/conscious) is located in…
(Also, subdivisions)
Hippocampus
Explicit –> declarative (facts/events)
Declarative —>
- Episodic (events/experiences)
- Semantic (faces, concepts)
Implicit memory (unconscious) is located in
Cerebellum, includes procedural memory (skills/tasks)
Entrohinal is ___ layers, neocortical
Hippocampus is ___ layers, transition from cortical to hippocampus.
Allocortex
6
3
What happened to HM?
Epilepsy
Temporal lobe parts removed bilaterally
Anterograde amnesia (no future)
What was removed from HM?
Most of amygdaloid complex
Hippocampus except for 2 cm at caudal end
Parahippocampal gurus (including Entrohinal, perirhinal, parahippocamphs cortices)
Anterograde amnesia
Procedural memory intact (kept cerebellum)
Inside the hippocampus pathway
Trisynaptic pathway
Granule cells –> CA3/CA2 (paraminal cells) –> CA1
Main LTP area is parametal? Cells in CA1 receiving connections from CA3
Where do Association areas of cortex project to?
Medial temporal lobe, specifically parahippocampal region.
Few inputs direct to hippocampus
What cortex (parahippocampal) is responsible for object recognition?
Perirhinal cortex
What cortex (parahippocampal region) is responsible for context, spatial cognition, navigation, object location?
Postrhinal cortex
Afferents/efferents to perirhinal cortex (PER) (ventral)
Inputs: Somatosensory/Amygdala
Afferents/efferents of postrhinal cortex
Input: Visual, superior colliculus
Projects to medial Entrohinal cortex (CA1/dorsal subiculum)
Overall: lateral hippocampus
Brodman area 28a
Olfactory/somatosensory
Overall: medial hippocampus
Brodman areas 28b
Convergence of ____ onto ____ is sufficient for place cell properties.
Spatial info (grid cells) and head direction
Convergence of grid cells onto CA1 is sufficient for place cell properties
The perfurent pathway
From Entrohinal to hippocampus
grid cells
Converge into CA1 for place cells in hippocampus.
Grid cells are human brain GPS. For spatial navigation:
Grid cells fire AP @ different points in environment on triangular grid such that within grid cells, it fired at one place in environment.
Grid cells clustered in hippocampus, spread out in mEC
Amygdala is located in _____ and overactive in anxiety
Medial temporal lobe
Within human amygdala, what are the 3 main groups of nuclei? And are they inputs or outputs?
Inputs: basolateral, corticomedial
Outputs: central nucleus
Circuitary within the amygdala is
Excitatory, glutaminergic
Central nucleus projects from amygdala are
Inhibitory
Output from amygdala mainly effects the
Autonomic nervous system
What do amygdala outputs to hypothalamus do?
active nervous system (sympathetic)
Hormones
HPA axis
Reactions
In amygdala, projections in basolateral group tend to be _____. Whereas projection neurons in central nucleus tend to be _____.
Excitatory
Inhibitory
Extinction
Formation of new memory that context or cue is no longer adverse.
What is the neurological difference between using the same context (but w/o shock) and using a modified context with the cue?
Context: hippocampus/amygdala
Cue: auditory/visual/amygdala
Activation of what two areas induces fear conditioning?
Lateral amygdala neurons
Sensory stimulus (auditory)
See an increase in freezing if you depolarize with
Rhodopsin
Intercalated cells
Small group inhibitory interneurons, role in extinction
When you kill them, less extinction.
Excited by infralimbic cortex and output to central nucleus.
What is the best case for LTP memory?
Amygdala
Postsynaptic depolarization, presynaptic stimulation.
LTP response to coordinated input important for memories
What do inputs from prelimbic area of PFC do?
Increase activity in fear neurons which INHIBIT excitation neurons and activate output by central nucleus.
What do inputs from infralimbic area of PFC do?
Increase activity of excitation neurons which inhibits fear neurons
______ in the amygdala is response to systemic stressors, such as inflammatory challenge and hemorrhage.
Central nucleus
________ in amygdala are respond more to psychological responses
Lateral/basolateral
_________ areas of amygdala are responsible for noise, restraint, and forced swim.
Medial amygdala and basolateral
