Cellular Networks

Question 1

Synapse

Answer 1

electrical signal is converted into a chemical signal

• inhibitory and exhibitory synapses

Question 2

Dendrite cable

Answer 2

• dendrites can be assumed as cylindric cables
• dendrite contains no active current sources –> passive conduction of potential
• -> damped exponentially

Question 3

Glial cells

Answer 3

work as connecting links and support

• nutrient supply of neurons
• control of synapse growth and repair

Question 4

EEG

Answer 4

• summed electrical activity by recording voltage fluctuations
• spatial and temporal summation of the neuronal field potentials varies
  1) bipolar: potential difference between 2 electrodes
  2) unipolar: potential difference against mean value of all electrodes or against reference electrode

–> signal type strongly depends on recording type

Question 5

Signal components

Answer 5

• alpha, beta, delta, gamma waves –> different frequencies

- state of consciousness is reflected in the EEG signal

Question 6

Brain Computer Interface

Answer 6

• enables conncetion between the brain and a computer without activating the peripheral nervous system
• record either electrical or hemodynamic activity of the brain

Question 7

Cardiac myocytes –> response to drug application

Answer 7

• first response: beat frequency change

- second response: change of extracellular signal shape

Question 8

Cell-surface adhesion

Answer 8

synthetic surfaces exposed to biological fluids adsorb proteins

• cells do not adhere directly to surfaces but to such protein layers
• cell secretes its own ECM to promote adhesion to technical surfaces

Question 9

Cell surface receptors

Answer 9

membrane-embedded proteins control signal transduction and cell adhesion

(adhesion, contraction, motility, secretion, proliferation)

Question 10

Extracellular matrix (ECM)

functions and components

Answer 10

ECM houses adhesion proteins that bind to cell receptor

functions: anchor cells, control cell orientation, regulate cell growth

components:
fibrous proteins

Question 11

Cell Adhesion Molecules (CAM)

Answer 11

• used to hold animal cells together
  –> 4 types:
  Cadherins
  Ig-like CAMs
  Selectins
  Integrin - binds cell to ECM

–> all for cell-cell adhesion, Integrin also binds to extracellular matrix

Question 12

Electroneurography (ENG)

Answer 12

method for determining the functional state of a peripheral nerve
- record nerve conduction velocities, amplitude, refractory time

Question 13

Electromyography (EMG)

Answer 13

electrical muscle activity is measured

Question 14

What are gap junctions?

Answer 14

pores that allow ion flow