Electrosensing

Question 1

How many times has passive electroreception independently evolved over the course of evolution?

Answer 1

Several times

Question 2

How many times has active electrosensation evovled?

Answer 2

At least twice

Question 3

When something evolves multiple times, what does that say about that the evolutionary pressure driving it?

Answer 3

The evolutionary pressure driving it is big/strong

Question 4

What is the morphological structure called responsible for passive electroreception?

Answer 4

Ampullary organ

Question 5

How is the ampullary organ generally organised (look like?)

Answer 5

Pore opening with mucous  alveoli  lumen with receptor epithelium  sensory nerve fibers connected to the receptor epithelium with supporting cells
It’s all covered by a collagen sheath

Question 6

What are the electroreceptive organs filled with and why?

Answer 6

Mucous, optimize and mediate the stimuli.

Question 7

Outline what happens when a receptor cell detects an electric signal, and what happens.

Answer 7

Na^+ channels is gated on the apical membrane  Na^+ influx  depolarization  Voltage gated Ca^2+ channels on the basal membrane  neurotransmitter release  nerve cell detects neurotransmitter  CNS processing

Question 8

How would you design an experiment with which you could demonstrate whether a fish has the capacity of electroreception or not?

Answer 8

By isolating the sense (slide 15)

Question 9

What kind of behaviours are associated with electroreception?

Answer 9

Prey detection, predator avoidance, intraspecific communication, object avoidance, geomagnetic navigation

Question 10

Describe the difference between passive and active electroreception.

Answer 10

Passive: perception of weak electric fields naturally occuring in the environment
Active: allows detection of an object’s properties, shape, size, and distance in 3D

Question 11

Describe the difference of capacitance and resistance.

Answer 11

Capacitance: the ability of an object to store an electric charge
Resistance: the difficulity with which to pass an electric current through a conductor

Question 12

Describe the difference between a conductor and a non-conductor.

Answer 12

COnductor: concentrates signal, easierly passed through
Non-conductor: spreads the signal away from object

Question 13

What are the different properties of organic vs non-organic objects?

Answer 13

Organic: high capacitance, low resistance
Non-organic: low capacitance, high resistance

Question 14

What cells sense the wave-form distortance?

Answer 14

Beta-cells

Question 15

What is the novelty response?

Answer 15

Environmental stimuli cause increased frequency of EODs –> higher temporal resolution

Question 16

What kind of information can be formed off of the slope-amplitude ratio?

Answer 16

Location and distance (analogi: sharpness of shadow enhances the closer the object is)