PSYCH 454 Lecture Notes - Lecture 10: Cytochrome C Oxidase, Visual Cortex, Complex Cell
24 May 2018
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Lecture 10: Visual Thalamus and Cortex- Types of Cells/Areas (3)
Simple Cells in primary visual cortex
●Simple cell RF has distinct ON and OFF regions (similar to ganglion cells + on/off regions
that were circular), but these = rectangular
○On-center region flanked on 1 or 2 sides by OFF region
○OR Off-center region flanked on 1 or 2 sides by ON region
○This RF arrangement yields orientation selectivity
■As you present light bar in OFF flanking
region→ no AP response
■ON flanking region→ AP response
●Converging (multiple) LGN input results simple cell RF
○In retina of LGN→ center-surround circular RF
■3 diff cells in LGN, all project onto
same V1 neuron
■V1 neuron is influenced by ALL LGN
neurons projecting to it→ on centers
form an elongated on region
●Flanking regions (off) are forming elongated off→ giving you sort
of a rectangle
○Multiple LGN cells with slightly offset center-surround RFs are thought to
produce simple cell RF
○Shape of simple cell on/off regions depends on RF of LGN neurons
Complex Cell
●Complex cell RF has no distinct ON and OFF regions
○respond to stimulus at preferred orientation anywhere in the RF
■Doesn’t care about location of light/stimulus in RF
○Same amount of neuronal response/AP firing no matter the orientation of the
light bar in the RF (edge, middle, angle→ doesn’t matter!)
●Complex cells constructed from simple cells
○Simple cells with same orientation selectivity → provide input to a complex
cell→ form complex cell preferred orientation
○# of different cells in V1 (different on/off flanking regions)→ provide input to
complex cell, which sums inputs from all cells
Blobs→ color processing in V1
●An enzyme called “cytochrome oxidase” is differentially distributed across V1
○Found in mitochondria, contributes to cellular respiration (energy production)
Document Summary
Lecture 10: visual thalamus and cortex- types of cells/areas (3) Simple cell rf has distinct on and off regions (similar to ganglion cells + on/off regions that were circular), but these = rectangular. On-center region flanked on 1 or 2 sides by off region. Or off-center region flanked on 1 or 2 sides by on region. As you present light bar in off flanking region no ap response. Converging (multiple) lgn input results simple cell rf. In retina of lgn center-surround circular rf. 3 diff cells in lgn, all project onto same v1 neuron. V1 neuron is influenced by all lgn neurons projecting to it on centers form an elongated on region. Flanking regions (off) are forming elongated off giving you sort of a rectangle. Multiple lgn cells with slightly offset center-surround rfs are thought to produce simple cell rf. Shape of simple cell on/off regions depends on rf of lgn neurons.
