1. Neuroscience Cellular and molecular neuroscience Neuroanatomy Systems neuroscience

2. The astonishing hypothesis Perception Thought Emotion Memory Consciousness Material processes in vast networks of neurons “You’re nothing but a pack of neurons.”

3. Perception Where physics meets psychology Vision Hearing Touch Etc.

4. Light Photon energy = Planck’s constant x frequency Wavelength x frequency = speed of light Wavelength Amplitude Figure by MIT OCW.

5. Electromagnetic spectrum White = superposition of all frequencies. Gamma rays X-rays Ultra-violet rays Infrared rays Radar Broadcast bands AC circuits Visible light VioletRed Higher energy Lower energy Wavelength (nm) Figure by MIT OCW.

6. Why is “visible” where it is? Notch in water absorption spectrum “Visible” light is what is available in the ocean. Evolution has exploited this fact. Image removed due to copyright reasons. Please see figure on page 291 in: Jackson, John David. Classical Electrodynamics. 3rd ed. New York: Wiley, 1999. ISBN: 047130932X.

7. Reflection and absorption Lightness - Dark objects absorb more than light ones Color - Frequency-dependent absorption Reflection Absorption Figure by MIT OCW.

8. Refraction Figure by MIT OCW.

9. Functions of the eye Forming a stable image on the retina Emphasizing spatial and temporal differences in images

10. Gross anatomy of the eye Figure by MIT OCW. After figure 9.4 in: Bear, Mark F., Barry W. Connors, and Michael A. Paradiso. Neuroscience: Exploring the Brain. 2nd ed. Baltimore, Md.: Lippincott Williams & Wilkins, 2001. ISBN: 0683305964.

11. Opthalmoscopic view Image removed due to copyright reasons. Please see figure 9.5 in: Bear, Mark F., Barry W. Connors, and Michael A. Paradiso. Neuroscience: Exploring the Brain. 2nd ed. Baltimore, Md.: Lippincott Williams & Wilkins, 2001. ISBN: 0683305964.

12. Blind spot demo Figure by MIT OCW. After Box 9.1 in: Bear, Mark F., Barry W. Connors, and Michael A. Paradiso. Neuroscience: Exploring the Brain. 2nd ed. Baltimore, Md.: Lippincott Williams & Wilkins, 2001. ISBN: 0683305964. Further reading: V.S. Ramachandran and S. Blakeslee, Phantoms in the Brain

13. Filling in Figure by MIT OCW. After Box 9.1 in: Bear, Mark F., Barry W. Connors, and Michael A. Paradiso. Neuroscience: Exploring the Brain. 2nd ed. Baltimore, Md.: Lippincott Williams & Wilkins, 2001. ISBN: 0683305964. Moral: perception is an active process. “Seeing is believing.” “Believing is seeing.”

14. Cross-sectional anatomy Figure by MIT OCW. After: Bear, Mark F., Barry W. Connors, and Michael A. Paradiso. Neuroscience: Exploring the Brain. 2nd ed. Baltimore, Md.: Lippincott Williams & Wilkins, 2001. ISBN: 0683305964.

15. Refraction by the cornea Figure by MIT OCW. After figure 9.7 in: Bear, Mark F., Barry W. Connors, and Michael A. Paradiso. Neuroscience: Exploring the Brain. 2nd ed. Baltimore, Md.: Lippincott Williams & Wilkins, 2001. ISBN: 0683305964. Focal Distance Refractive Power (Dlopters) Focal Distance (m)

16. Accommodation Figure by MIT OCW. After figure 9.8 in: Bear, Mark F., Barry W. Connors, and Michael A. Paradiso. Neuroscience: Exploring the Brain. 2nd ed. Baltimore, Md.: Lippincott Williams & Wilkins, 2001. ISBN: 0683305964.

17. Visual field Figure by MIT OCW. After figure 9.9 in: Bear, Mark F., Barry W. Connors, and Michael A. Paradiso. Neuroscience: Exploring the Brain. 2nd ed. Baltimore, Md.: Lippincott Williams & Wilkins, 2001. ISBN: 0683305964. Retinal images are inverted.

18. Visual angle Figure by MIT OCW. After figure 9.10 in: Bear, Mark F., Barry W. Connors, and Michael A. Paradiso. Neuroscience: Exploring the Brain. 2nd ed. Baltimore, Md.: Lippincott Williams & Wilkins, 2001. ISBN: 0683305964. Distance on the retina corresponds to visual angle. 20/20 vision= resolution of 1/12 degree

19. Retinal circuitry Output Ganglion cell axons Projecting to forebrain Amacrine cell Bipolar cell Horizontal cell Direct pathway Ganglion cells Photoreceptors Input Figure by MIT OCW. After figure 9.11 in: Bear, Mark F., Barry W. Connors, and Michael A. Paradiso. Neuroscience: Exploring the Brain. 2nd ed.Baltimore, Md.: Lippincott Williams & Wilkins, 2001. ISBN: 0683305964.

20. Laminar organization Figure by MIT OCW. After figure 9.12 in: Bear, Mark F., Barry W. Connors, and Michael A. Paradiso. Neuroscience: Exploring the Brain. 2nd ed. Baltimore, Md.: Lippincott Williams & Wilkins, 2001. ISBN: 0683305964. Ganglion Cell Layer Inner Plexiform Layer Inner Nuclear Layer Outer Plexiform Layer Outer Nuclear Layer Layer of Photoreceptor Outer Segments Pigmented Epithelium

21. Rods and cones Figure by MIT OCW. After figure 9.13 in: Bear, Mark F., Barry W. Connors, and Michael A. Paradiso. Neuroscience: Exploring the Brain. 2nd ed. Baltimore, Md.: Lippincott Williams & Wilkins, 2001. ISBN: 0683305964. Cell bodies Scotopic/night Vision 1000 x more Light sensitive photoreceptor Synaptic terminals Inner segments Photopic/day vision Color vision Outer segments Cone Photo- recepto

22. Spatial organization Photoreceptors less dense in periphery Ratio of photoreceptors to ganglion cells higher in the periphery Acuity is lower, sensitivity higher in the periphery Images removed due to copyright reasons. Please see figures 9.14 a and b in: Bear, Mark F., Barry W. Connors, and Michael A. Paradiso. Neuroscience: Exploring the Brain. 2nd ed. Baltimore, Md.: Lippincott Williams & Wilkins, 2001. ISBN:0683305964.

23. Fovea in cross section Figure by MIT OCW. After figure 9.15 in: Bear, Mark F., Barry W. Connors, and Michael A. Paradiso. Neuroscience: Exploring the Brain. 2nd ed. Baltimore, Md.: Lippincott Williams & Wilkins, 2001. ISBN: 0683305964. Lateral displacement of ganglion cells at fovea improves acuity

24. Neurotransmission and phototransduction Figure by MIT OCW. After figures 9.16 a and b in: Bear, Mark F., Barry W. Connors, and Michael A. Paradiso. Neuroscience: Exploring the Brain. 2nd ed. Baltimore, Md.: Lippincott Williams & Wilkins, 2001. ISBN: 0683305964.

25. Response to light Dark current due to open sodium channels Light depletes cGMP, closing sodium channels Figure by MIT OCW. After figures 9.17 a and b: Bear, Mark F., Barry W. Connors, and Michael A. Paradiso. Neuroscience: Exploring the Brain. 2nd ed. Baltimore, Md.: Lippincott Williams & Wilkins, 2001. ISBN: 0683305964.

26. Rhodopsin photoactivation Figure by MIT OCW. After figure 9.18 in: Bear, Mark F., Barry W. Connors, and Michael A. Paradiso. Neuroscience: Exploring the Brain. 2nd ed. Baltimore, Md.: Lippincott Williams & Wilkins, 2001. ISBN: 0683305964. Opsin has seven transmembrane alpha helices, like other GPCRs

27. Signaling cascade Images removed due to copyright reasons. Please see figures 9.19 a and b in: Mark F. Bear, Barry W. Connors, Michael A. Paradiso. Neuroscience: Exploring the Brain. 2nd ed. Baltimore, Md.: Lippincott Williams & Wilkins, 2001. ISBN: 0683305964.

28. Chemical amplification Each rhodopsin activates many G-proteins Each PDE converts many cGMPs Detection of a single photon is possible! Further reading: B. Sakitt, Counting every quantum, J. Physiol. (London) 223:131-150, 1972. P.B Detwiler et al., Engineering aspects of enzymatic signal transduction: photoreceptors in the retina, Biophys. J. 79:2801-17 (2000). R.W. Rodieck, The first steps in seeing, Sinauer (1998).