This document summarizes key aspects of neurons and neurotransmission. It describes the basic anatomy of neurons including the cell body, dendrites, and axon. It explains how electrical signals called action potentials are conducted down axons and transmitted across synapses to other neurons. The roles of ion channels and neurotransmitters in generating and transmitting these signals are also outlined. Finally, it provides an overview of supporting glial cells in the brain and peripheral nervous system.

2. Neurons

8. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Association
neuron
Cell
Cell body body
Axon
Dendrites 2
3
Cell body Axon Motor
neuron
Axon
1
Sensory Direction of
neuron conduction
Dendrites

9. Dendrites

11. Axons

13. Figure 12-31 Essential Cell Biology (© Garland Science 2010)

14. Glial Cells

16. Roughly 3 times
more glia than neurons

17. Astrocytes

20. Structural
Glycogen fuel reserve buffer
Metabolic support
Blood–brain barrier?
Transmitter uptake and release
Regulation of ion concentration
in the extracellular space
Modulation of synaptic transmission
Vasomodulation
Promotion of the myelinating activity
of oligodendrocytes
Nervous system repair
Long-term potentiation

21. Text

22. Maintain an appropriate
chemical environment
for neuronal signaling

23. Microglia

24. Macrophages
of the CNS

26. Scavenging
Phagocytosis
Cytotoxicity
Antigen presentation
Synaptic stripping
Promotion of repair
Extracellular signaling

28. Oligodendrocytes

29. A.M. BUTT, K. COLQUHOUN, AND M. BERRY

32. Schwann Cells

33. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Dendrites
Schwann
cell
Schwann
cell
Axon
Nucleus
Axon
Schwann
Myelin cell
sheath
Axon
Myelin sheath

34. Myelin

36. “...fatty substance that
surrounds the axons
of many neurons.”

37. “...wrapping their cell membranes
around the axon in a concentric
manner.”

38. Water: 40%
Remainder:
70 - 85% Lipids
15 - 30% Proteins

41. Action Potential

50. Membrane
Depolarization

51. Figure 12-33 Essential Cell Biology (© Garland Science 2010)

52. Voltage-Gates
Sodium Channels

54. Figure 12-34 Essential Cell Biology (© Garland Science 2010)

55. Figure 12-35 Essential Cell Biology (© Garland Science 2010)

56. Membrane
Repolarization

58. Voltage-Gated
Potassium Channels

60. Figure 12-29 Essential Cell Biology (© Garland Science 2010)

62. Figure 12-39b Essential Cell Biology (© Garland Science 2010)

67. Synaptic
Transmission

69. Figure 12-40a Essential Cell Biology (© Garland Science 2010)

70. Figure 12-40b Essential Cell Biology (© Garland Science 2010)

71. Voltage-Gated
Calcium Channels

72. Figure 12-41 Essential Cell Biology (© Garland Science 2010)

73. Figure 12-42 Essential Cell Biology (© Garland Science 2010)

79. Figure 5.14 Molecular mechanisms of exocytosis during neurotransmitter release (Part 2)

80. Figure 5.9 Local recycling of synaptic vesicles in presynaptic terminals (Part 2)

81. Neurotransmitters

83. Excitatory

88. Inhibitory

89. Figure 5.3 Sequence of events involved in transmission at a typical chemical synapse

90. Figure 5.23 Events from neurotransmitter release to postsynaptic excitation or inhibition

91. Figure 12-45b Essential Cell Biology (© Garland Science 2010)

92. Figure 12-45a Essential Cell Biology (© Garland Science 2010)

93. Neurotransmitter
Biosynthesis

95. Small Molecules

96. Figure 5.5 Metabolism of small-molecule and peptide transmitters (Part 1)

97. Figure 5.5 Metabolism of small-molecule and peptide transmitters (Part 2)

98. Neuropeptides
(Peptide Neurotransmitters)

99. β-endorphin

100. Figure 5.5 Metabolism of small-molecule and peptide transmitters (Part 3)

101. Figure 5.5 Metabolism of small-molecule and peptide transmitters (Part 4)

102. Electrical Synapses

103. Figure 5.1 Structure of electrical synapses (Part 1)

105. Gap Junctions

107. Figure 5.1 Structure of electrical synapses (Part 3)

108. Figure 5.1 Structure of electrical synapses (Part 2)

110. Axon

111. Glial Cell
Axon

112. Axon

113. Myelin
Axon