1. The Nose

2. Stapes Malleus Incus Tympanic Membrane The middle ear amplifies signal by increasing the pressure on the oval window Inner ear muscles provide adjustable intensity control (dampen sounds)

3. Basal Apical ThickThin StiffFloppy High frequencyLow frequency stapes Basilar membrane

4. We Love Fourier!

6. One Version of the Auditory Pathway cochlear nucleus superior olive IC MGN A1 cochlear nucleus superior olive IC MGN A1

7. 1. Receptor Cells (Graded potential) (input) 2. Bipolar Cells (Graded potential) 3. Ganglion Cells (action potential) (Output) Different cells in the retina Back of eye Front of eye 4. Horozontal Cells (Graded potential) 5. Amacrine Cells (Graded/action potential) 6. Pigment cells

8. Distribution of Rods and Cones

9. RodsCones High light sensitivity Night vision Low light sensitivity Day vision AchromaticChromatic Low acuity—not in the fovea High acuity—in the fovea Slow responseFast response

10. General organization of the visual pathway

11. Receptive field Definition: the area of the retina (or visual field) in which light signals evoke responses It’s a property of the cell, not a cell or a part of the cell It depends largely on the synaptic inputs to the cell and to some degree the biophysical property of the cell itself

13. LGN cells cortical simple cell receptive field

14. LGN layers

15. Parvocellular layers: 3-6 Magnocellular layers: 1,2 Contralateral eye: 1,4,6 Ipsilateral eye: 2,3,5 But all LGN layers represent contralateral visual field!

16. Yang Dan is Way too Cool

17. Circuitry -- inputs, outputs and layering Input LGN  layer 4, layer 6 Layer 4  layer 2/3  layer 5  layer 6 Output Layer 2/3, Layer 4B  other visual cortical areas Layer 5  superior colliculus Layer 6  LGN 2/3 4 4A 4B 4C  4C  5 6 M P (LGN) 1

18. right visual fieldleft visual field fixation point temporal half nasal half temporal half optic chiasm V1 nasal retina  contra LGN temporal retina  ipsi LGN L visual field  R LGN  R V1 R visual field  L LGN  L V1 leftright nasal half V1 LGN

19. LR radioactive amino acid 2 C I I I C C layer 4 RLRLL LGN V1 eye 5 4 3 2 1 6 Transneuronal transport technique to look at OD columns

20. V1 cells have orientation selectivity orientationresponse LGN cells cortical simple cell receptive field 2/3 4 5 6 1

21. Hypercolumn layers One L/R cycle + one 180 o rotation = one hypercolumn. cortical surface 180 o, ~1mm