Describe four staining methods, show how they complement each other and think what types of questions each method could answer.

1)Based on laboratory observations (direct or indirect) draw following neurons or structures, provide spatial scale to each drawing:
1.1) Cortical pyramidal neuron

Purkinje neuron from cerebellum

6 layers of neocortex with different neuronal types

2)In a thought experiment, let’s imagine neuronal tissue enlarged 10,000 times in each direction. This way the objects of our study – neurons and neuronal networks – will reach dimensions of everyday objects we have experience with, and we will be able to visualize and understand their proportions and complexity better.

Make the following calculations:

actual dimension enlarged dimensions

neuronal cell body 10-20 micrometers in diameter ___________________
compare to everyday objects: ___________________

axon diameter ~1 micrometer ____________________

length of an axon millimeters, (up to 1 meter) ____________________
How far would the enlarged axon reach from your current location? ____________________

total dendritic length ~15 mm ____________________

size of a synapse 1-2 micrometers ____________________

synaptic gap 20-40 nanometers ____________________

density of synapses on dendrite ~1 per micrometer ____________________

density of neurons 100 000 per mm3 ____________________
How many enlarged neurons would fit into a telephone booth? ____________________

area of human neocortex 40 cm x 40 cm ____________________
How large area of your hometown would be covered by enlarged cortex? ____________________

3) Essay question: Describe four staining methods, show how they complement each other and think what types of questions each method could answer. (Provide one-page answer.)