Chapter 2Nerve Cells and Behavior

&Chapter 4

The Cytology of Neurons

25 nm

7 nm25 nm

Neuronal cytoskeleton

4. Transmit information to target cell (neuron, muscle, gland)

Four functions of neurons

1. Receive and integrate inputs

2. Generate a nerve impulse (action potential)

3. Conduct the action potential

dendrites, soma

axon hillock

axon

nerve terminals

Dendrites and cell body

Receive and integrate inputs

Axon hillock and initial segment

Generate action potentials

Axon

Conducts action potential

Terminals

Synaptic transmission

Eccles, J.C. (1964) The Physiology of Synapses. N.Y.: Springer

Classifications of Neurons

1. Functiona. sensory neurons

b. motoneurons

c. interneurons

Classifications of Neurons

1. Function

2. Structurea. unipolar

b. bipolarc. multipolar

Classifications of Neurons

1. Function

2. Structure

3. Shapee.g., pyramidal, stellate, basket, granule, etc.

100μm

B

A

Classifications of Neurons

1. Function

2. Structure

3. Shape

4. Effecta. excitatory neurons

b. inhibitory neurons

Classifications of Neurons

1. Function

2. Structure

3. Shape

4. Effect

5. Axon lengtha. projection neurons (Golgi Type I)

b. local neurons (Golgi Type II)

Classifications of Neurons

1. Function

2. Structure

3. Shape

4. Effect

5. Axon length

6. Neurochemical identitye.g., cholinergic, dopaminergic, GABAergic, etc.

Classifications of Neurons

1. Function

2. Structure

3. Shape

4. Effect

5. Axon length

6. Neurochemical identity

Types of glial cells

1. Astrocytes

2. Microglia

3. Oligodendroglia

4. Schwann cells

Types of glial cells

1. Astrocytesa. mechanical support

b. metabolic support

transport nutrients and wastes

c. encapsulate synapses

d. regulate chemical and ionic environment

e. form scar tissue

f. act as phagocytes

Types of glial cells

1. Astrocytes

2. Microgliaa. act as phagocytesb. part of brain’s immune system

Types of glial cells

1. Astrocytes

2. Microglia

3. Oligodendrogliamyelinate axons of central nervous system

Types of glial cells

1. Astrocytes

2. Microglia

3. Oligodendroglia

4. Schwann cellsmyelinate axons of peripheral nervous system