1. Nervous and Sensory Systems!

2. Justin Rice bioTAjustin@yahoo
Justin Rice Office Hours: 2-3, Thursdays, Socrates Center
Recitations: Tuesdays 9:10-10:00 N C114, :00-7:50 W 116

3. Vocab Pineal gland pinea=pine cone Pons pons=bridge
Lingual gyrus lingua=tongue
Hippocampus sea horse
Amygdala almond
Geniculate genu =knee e.g. genuflection
Fusiform spindle shaped
Pulvinar pillow
Pyriform pear shaped
Vermis worm e.g. vermiform appendix
Ipsi same (e.g. ipsilateral cortex)
Contra opposite, against (e.g. contralateral)

4. Reading list… Oliver Sacks… -”Man who mistook his wife for a hat”
-”The island of the colorblind”
-”Musicophilia”
Eric Kandel
-”In Search of Memory”

5. Division

6. Division

7. Sympathetic vs Parasympathetic Division

8. Sensory information enters brain via ‘’reticular formation’’

9. Info gets processed in different parts of your brain
Gustatory (Insula)
Smell (olfactory)

10. Can Mess with them using TMS (trans-cranial-magnetic-stimulation)

11. Motor and somatosensory cortex

12. Olfactory cortex (bulb)

13. Olfactory cortex (bulb)

14. Visual Cortex

15. Insula (gustatory cortex – a mysterious place) -also closely linked to addiction

16. Some MRIs

17. Some MRIs

18. Some MRIs

20. We’re focusing right here

21. Taste

22. Each cell has different mechanism

23. Each cell has different mechanism
Glutamate
Note: IP3=inositol triphosphate is another second messenger
Note: ~40 different bitter receptors in humans

24. Question 107
Certain medications selectively block certain ion channels. Which ion channel blocker would you expect to interfere with your sense of sweet taste?
Dihydropyridine – a voltage gated calcium channel blocker used to lower blood pressure
Delta-conotoxin – a poison from the cone snail that inhibits deactivation of voltage gated sodium channels
Pandinotoxin – a poison from the emperor scorpion, which inhibits the opening of voltage gated potassium channels
None of the above
All of the above

25. Question 107
Certain medications selectively block certain ion channels. Which ion channel blocker would you expect to interfere with your sense of sweet taste?
Dihydropyridine – a voltage gated calcium channel blocker used to lower blood pressure
Delta-conotoxin – a poison from the cone snail that inhibits deactivation of voltage gated sodium channels
Pandinotoxin – a poison from the emperor scorpion, which inhibits the opening of voltage gated potassium channels
None of the above
All of the above

26. Miracle Berries contain ‘’miraculin’’
-Strongly Binds to sweet receptor binding site at neutral pH
-but only activates receptor at low pH

27. Question 108
What effect will miracle berries have on your taste of different foods?
Bitter foods will taste sweet
Sweet foods will taste sour
Sour foods will taste sweet
Sweet foods will taste bitter
None of the above

28. Question 108
What effect will miracle berries have on your taste of different foods?
Bitter foods will taste sweet
Sweet foods will taste sour
Sour foods will taste sweet
Sweet foods will taste bitter
None of the above
-Strongly Binds to sweet receptor binding site at neutral pH
-but only activates receptor at low pH

29. Bitter tastes (~550 known)
strychnine
cyanide

30. Sweet tastes
Saccharin
steviol

31. Smell -~900 receptors in humans -lots of gene duplication events
-Many odors activate multiple receptors
-can smell gazillions of stuff
(refer to Dani’s lecture for details)

32. Smell Very weird -~900 receptors in humans
-lots of gene duplication events
-Many odors activate multiple receptors
-can smell gazillions of stuff
(refer to Dani’s lecture for details)

33. Smell -Brain eating amoeba travels through cribriform plate!
-first symptoms – altered sense of smell…

34. Stretch receptors in muscles (propioception)
Oligod

35. Mechanoreception -lots of different neurons, a few different receptor hypotheses:

36. Thermosensation

37. Speaker and Microphone
Solenoid – changing current
changing magnetic field
magnet moves
Diaphragm moves
Air moves

38. Speaker and Microphone
Solenoid – changing current
changing magnetic field
magnet moves
Diaphragm moves
Air moves

39. Speaker and Microphone
Solenoid – changing current
changing magnetic field
magnet moves
Diaphragm moves
Air moves
Solenoid – Air moves
=>Diaphragm moves
Magnet moves
Magnetic field changes
Current is induced

40. Hearing

41. Hearing

42. Hearing
Stapes pushes against perilymph-transmitting the sound waves

43. Hearing

44. Hearing

45. What about the frequency?
Basilar membrane gets wider towards the center – more floppy (lower resonance frequency)
Implicit Fourier decomposition

46. Amplification of soft sounds
Outer hair cells
inner hair cells
(also contain a special motor protein, “prestin”, which can make them wiggle, amplifying the sound) => otoacoustic emissions

47. Question 109
Pesticide tributyltin has a very long half-life, and has been used for decades as a pesticide on ocean ship-bottoms, to avoid barnacle and algae growth. Recent studies have shown that tributyltin interferes with prestin function. One might expect this to cause:
Global warming
High affinity between dogs and tennis balls
partial-deafness in marine mammals
Corruption in congress
None of the above

48. Cochlear implants

49. Gravity, movement sensation
Don’t forget plants!

50. Gravity, movement sensation
Don’t forget plants!
In the utricle
(horizontal)
In the sacule
(verticle)

51. Rotational Acceleration…

52. Question 110
Sometimes, due to excessive shaking or head trama, otoliths can be rattled out of the utricle or saccule and into the semi-circular canals. What symptom would you imagine this would cause?
The ability to hear gravity
Sensation of falling when you turn your head
Sensation of spinning when you stand up
Sensation of falling when you hear a noise
None of the above

53. Question 110
Sometimes, due to excessive shaking or head trama, otoliths can be rattled out of the utricle or saccule and into the semi-circular canals. What symptom would you imagine this would cause?
The ability to hear gravity
Sensation of falling when you turn your head
Sensation of spinning when you stand up
Sensation of falling when you hear a noise
None of the above

54. Question 110
Sometimes, due to excessive shaking or head trama, otoliths can be rattled out of the utricle or saccule and into the semi-circular canals. What symptom would you imagine this would cause?
The ability to hear gravity
Sensation of falling when you turn your head
Sensation of spinning when you stand up
Sensation of falling when you hear a noise
None of the above
(Benign paroxysmal positional vertigo) - ~1 million doctor visits/year

55. Question 110
Sometimes, due to excessive shaking or head trama, otoliths can be rattled out of the utricle or saccule and into the semi-circular canals. What symptom would you imagine this would cause?
The ability to hear gravity
Sensation of falling when you turn your head
Sensation of spinning when you stand up
Sensation of falling when you hear a noise
None of the above
(Benign paroxysmal positional vertigo) - ~1 million doctor visits/year

56. Vision

57. Vision
Cones and Rods, bipolar and ganglion cells

58. Vision

59. Vision
Optic nerve
Retinal artery
fovea
Macula=spot

60. Vision Very different appearance
Rods are very sensitive-black and white vision
Cones come in red, blue, and green flavors, and sense color
Both Release GLUTAMATE when depolarized

61. Rods

62. Vision
Both have membrane stacks

63. Vision
Light causes cis-trans isomerization
Rhodopsin changes shape

64. Rods: Black and White (really, purple) Vision

65. What does phosphodiesterase do?
Cyclic GMP
GMP
It cleaves a phospho-diester bond

66. Question 111
Lets say you were staring out the window during the day, when all of a sudden a phosphodiesterase inhibitor was introduced to the rod cells in your eyes?
The membrane voltage will go up, and the rods will release more glutamate
The membrane voltage will go down, and the rods will release less glutamate
The membrane voltage will go down, and the rods will release less acetylcholine
The membrane voltage will go up, and the rods will release more acetylcholine
None of the above

67. Question 111
Lets say you were staring out the window during the day, when all of a sudden a phosphodiesterase inhibitor was introduced to the rod cells in your eyes?
The membrane voltage will go up, and the rods will release more glutamate
The membrane voltage will go down, and the rods will release less glutamate
The membrane voltage will go down, and the rods will release less acetylcholine
The membrane voltage will go up, and the rods will release more acetylcholine
None of the above
PDE causes cGMP->GMP
-> sodium channels close
-> membrane voltage becomes more negative
-> less glutamate is released.
PDE inhibitor - > opposite series of events -> more glutamate is released

68. Question 111
Lets say you were staring out the window during the day, when all of a sudden a phosphodiesterase inhibitor was introduced to the rod cells in your eyes?
The membrane voltage will go up, and the rods will release more glutamate
The membrane voltage will go down, and the rods will release less glutamate
The membrane voltage will go down, and the rods will release less acetylcholine
The membrane voltage will go up, and the rods will release more acetylcholine
None of the above

69. Color Vision Different cones express different “iodopsins”
Same mechanism as rhodopsin, but differ by a few amino acids to change absorption peaks

70. Coordination in retina
In darkness, rods and cones (at ~-40mV) are constantly releasing glutamate
-with light, Na+ channels close, cells hyperpolarize, and glutamate stops.
-in response, some bipolar cells depolarize, while others hyperpolarize

71. Question 112
Given their two opposite responses to glutamate, we might guess that bipolar cells…
Each have both glutamate-binding sodium channels and glutamate binding chlorine channels
Come in two types, one with glutamate-gated sodium channels, and one with acetylcholine-gated sodium channels
Come in two types, one with glutamate-gated sodium channels, and one with a metabotropic glutamate receptor, which causes the closing of calcium/sodium channels
None of the above
All of the above

72. Question 112
Given their two opposite responses to glutamate, we might guess that bipolar cells…
Each have both glutamate-binding sodium channels and glutamate binding chlorine channels
Come in two types, one with glutamate-gated sodium channels, and one with acetylcholine-gated sodium channels
Come in two types, one with glutamate-gated sodium channels, and one with a metabotropic glutamate receptor, which causes the closing of calcium/sodium channels
None of the above
All of the above

73. Question 112
Given their two opposite responses to glutamate, we might guess that bipolar cells…
Each have both glutamate-binding sodium channels and glutamate binding chlorine channels
Come in two types, one with glutamate-gated sodium channels, and one with acetylcholine-gated sodium channels
Come in two types, one with glutamate-gated sodium channels, and one with a metabotropic glutamate receptor, which causes the closing of calcium/sodium channels
None of the above
All of the above

74. OFF vs ON bipolar cells

75. Question 113
The phosphodiesterase in rod and cone cells is PDE6. Sildafenil (Viagra) is a well known PDE5 inhibitor, but it has also been shown to partially inhibitor PDE6. A common side effect of Viagra is cyanopsia (blue vision), indicating that sildenafil somehow works differently on some cone cells than others. Given what you know from class, pick the most likely cause:
Sildenafil is a better inhibitor of PDE6 in S than it is in M and L cone cells
Sildenafil is a better inhibitor of PDE6 in L than it is in S and M cone cells
Sildenafil is a worse inhibitor of PDE6 in L than it is in S and M cone cells
Sildenafil is a worse inhibitor of PDE6 in S than it is in M and L cone cells

76. Question 113
The phosphodiesterase in rod and cone cells is PDE6. Sildafenil (Viagra) is a well known PDE5 inhibitor, but it has also been shown to partially inhibitor PDE6. A common side effect of Viagra is cyanopsia (blue vision), indicating that sildenafil somehow works differently on some cone cells than others. Given what you know from class, pick the most likely cause:
Sildenafil is a better inhibitor of PDE6 in S than it is in M and L cone cells
Sildenafil is a better inhibitor of PDE6 in L than it is in S and M cone cells
Sildenafil is a worse inhibitor of PDE6 in L than it is in S and M cone cells
Sildenafil is a worse inhibitor of PDE6 in S than it is in M and L cone cells

77. Question 113
The phosphodiesterase in rod and cone cells is PDE6. Sildafenil (Viagra) is a well known PDE5 inhibitor, but it has also been shown to partially inhibitor PDE6. A common side effect of Viagra is cyanopsia (blue vision), indicating that sildenafil somehow works differently on some cone cells than others. Given what you know from class, pick the most likely cause:
Sildenafil is a better inhibitor of PDE6 in S than it is in M and L cone cells
Sildenafil is a better inhibitor of PDE6 in L than it is in S and M cone cells
Sildenafil is a worse inhibitor of PDE6 in L than it is in S and M cone cells
Sildenafil is a worse inhibitor of PDE6 in S than it is in M and L cone cells
normally phosphodiesterase deactivates cGMP-GMP
->closes Na+ channels
->hyperpolarizes cone cells
->stops glutamate from going to Bipolar cells
->causes sensation of “seeing something”

78. Question 113
The phosphodiesterase in rod and cone cells is PDE6. Sildafenil (Viagra) is a well known PDE5 inhibitor, but it has also been shown to partially inhibitor PDE6. A common side effect of Viagra is cyanopsia (blue vision), indicating that sildenafil somehow works differently on some cone cells than others. Given what you know from class, pick the most likely cause:
Sildenafil is a better inhibitor of PDE6 in S than it is in M and L cone cells
Sildenafil is a better inhibitor of PDE6 in L than it is in S and M cone cells
Sildenafil is a worse inhibitor of PDE6 in L than it is in S and M cone cells
Sildenafil is a worse inhibitor of PDE6 in S than it is in M and L cone cells
normally phosphodiesterase deactivates cGMP-GMP
->closes Na+ channels
->hyperpolarizes cone cells
->stops glutamate from going to Bipolar cells
->causes sensation of “seeing something”
Inhibiting PDE6 in an S cell causes you to not see blue
-> must work better in M and L cells

79. Question 113
The phosphodiesterase in rod and cone cells is PDE6. Sildafenil (Viagra) is a well known PDE5 inhibitor, but it has also been shown to partially inhibitor PDE6. A common side effect of Viagra is cyanopsia (blue vision), indicating that sildenafil somehow works differently on some cone cells than others. Given what you know from class, pick the most likely cause:
Sildenafil is a better inhibitor of PDE6 in S than it is in M and L cone cells
Sildenafil is a better inhibitor of PDE6 in L than it is in S and M cone cells
Sildenafil is a worse inhibitor of PDE6 in L than it is in S and M cone cells
Sildenafil is a worse inhibitor of PDE6 in S than it is in M and L cone cells

80. Question 114
Blood is supplied to the rods, cones, bipolar cells, and ganglion via the retinal artery, which branches out into little arterioles, shown on the right. High intraocular pressure can collapse these arterioles, leading to the slow hypoxic death of ganglion cells (this is called ‘’glaucoma’’)
This process begins farthest from the optic nerve, and slowly progresses inward. What would you expect to be symptoms of glaucoma?
Progressive loss of color vision around the focal point
Progressive loss of peripheral vision (both color and black/white)
Progressive loss of color peripheral vision
Progressive loss of black and white vision around the focal point
Progressive loss of all vision at the focal point

81. Question 114
Blood is supplied to the rods, cones, bipolar cells, and ganglion via the retinal artery, which branches out into little arterioles, shown on the right. High intraocular pressure can collapse these arterioles, leading to the slow hypoxic death of ganglion cells (this is called ‘’glaucoma’’)
This process begins farthest from the optic nerve, and slowly progresses inward. What would you expect to be symptoms of glaucoma?
Progressive loss of color vision around the focal point
Progressive loss of peripheral vision (both color and black/white)
Progressive loss of color peripheral vision
Progressive loss of black and white vision around the focal point
Progressive loss of all vision at the focal point

82. Question:

83. Question:

84. Various colorblindnesses

85. Question 115
The gene for S-cone opsin (blue) is on chromosome 7, while the genes for L-cone (red) and M-cone (green) opsin are on the X chromosome. Colorblindness caused by problems with opsin is a recessive trait.
Let’s say a man who can’t see green has children with a woman with normal vision. Their first is a son, who can’t see red. What’s the likelyhood that their second son can see red? 0%
25%
50%
75%
100%

86. Question 115
The gene for S-cone opsin (blue) is on chromosome 7, while the genes for L-cone (red) and M-cone (green) opsin are on the X chromosome. Colorblindness caused by problems with opsin is a recessive trait.
Let’s say a man who can’t see green has children with a woman with normal vision. Their first is a son, who can’t see red. What’s the likelyhood that their second son can see red? 0%
25%
50%
75%
100%
Dad: XR Y
Mom: XR XRXR XRY
Xr XrXR XrY

87. What if we had more iodopsins?
Birds have 4
(can see in UV)
“tetra-chromats”

88. What if we had more iodopsins?
Birds have 4
(can see in UV)
“tetra-chromats”
So do some women! (red and green opsin genes are on X chromosome) – can be mosaic for different iodopsins

89. What if we had more iodopsins?
Birds have 4
(can see in UV)
“tetra-chromats”
So do some women! (red and green opsin genes are on X chromosome) – can be mosaic for different iodopsins
Mantis-shrimp have 20!

90. Melanopsin! (just for fun)
Found in ‘’intrinsically photosensitive retinal ganglion cells” (ipRGCs)
Absorb blue/violet light, ~460nm
Modulate circadian rhythm
and pupil dilation reflex

91. Cis retinal is “dichroic”

92. Cis retinal is “dichroic”

93. Cis retinal is “dichroic”

94. Squid and octopus can see polarization of light

95. Squid and octopus can see polarization of light

96. Squid and octopus can see polarization of light

97. Squid and octopus can see polarization of light

98. Channel Rhodopsin
found in algae

99. How about fluorescent sensing?
Fuse two genes – Green Fluorescent protein and Calmodulin
-Genetically engineer to be expressed in some neurons, but not others
-when calcium is present, it binds to calmodulin, which changes shape, thus changing the shape of the GFP, thus changing the color of GFP
-can visualize synaptic activity

100. Sea turtles can sense electromagnetic fields
No one really understands how – best guess is that they use light to homolytically break a bond (probably in a cryptochrome) to form a radical pair
-which then does some weird quantum mechanical thing

101. Sea turtles can sense electromagnetic fields
No one really understands how – best guess is that they use light to homolytically break a bond (probably in a cryptochrome) to form a radical pair
-which then does some weird quantum mechanical thing

102. Explain this!