1. Overview and Passive Membranes

2. Sketch of Cerebellar Neurons by Santiago Cajal (1899)
A: Purkinje cells
B: Granule cells
How do these cells work?

3. A Single Neuron
A stained neuron with an extensive dendritic tree

4. A Population of Neurons
Several stained and possibly interconnected neurons

5. C. Elegans Wikipedia 302 neurons, 56 glial cells
contained in head and tail ganglia
and a spinal cord-like ventral nerve

6. Grasshopper Nervous System
Nerve cells in ganglia,, connected by a
spinal cord-like structure

7. The Leech

8. Leech Ganglia

9. Crab Pyloric Network From the Eve Marder lab, Brandeis University
Contained within the stomatogastric ganglion, which has about 30 neurons
that comprise two central pattern generators, the pyloric network and the gastric
mill network

10. Structure of a Neuron

11. Communication via a Chemical Synapse

12. Communication via a Chemical Synapse
Electron micrograph showing a chemical synapse. From Lodish, 4th edition.

13. Neuronal Action Potential

14. Electrical Impulses are Ubiquitous

15. Pioneers of Modern Neuroscience
Alan Hodgkin
( )
Andrew Huxley
( )

16. Atomic Model of an Ion Channel
The bacterial KcsA K+ channel

17. Ion Flow Through an Ion Channel
Only the K+ ions get through, the Cl- stays put. The membrane
acts as a semipermeable membrane.

18. Electrodiffusion Through a Semipermeable Membrane
Diffusion – flow of atoms down the K+ concentration gradient
Electrical drift – flow of ions due to electrical potential
Electrodiffusion – flow of ions due to combination of diffusion and
electrical drift

19. Nernst Potentials
Relative locations of Nernst and resting potentials

20. The Plasma Membrane

21. An Equivalent Circuit

22. A Capacitor
A capacitor is like a moat surrounding a castle: it separates inside from
outside. A deep moat is like a small Dielectric, making it hard to pass
from one side to the next. In the membrane, the dielectric reflects the lipids.

23. Membrane Time Constant