Electrosensing Flashcards
How many times has passive electroreception independently evolved over the course of evolution?
Several times
How many times has active electrosensation evovled?
At least twice
When something evolves multiple times, what does that say about that the evolutionary pressure driving it?
The evolutionary pressure driving it is big/strong
What is the morphological structure called responsible for passive electroreception?
Ampullary organ
How is the ampullary organ generally organised (look like?)
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
What are the electroreceptive organs filled with and why?
Mucous, optimize and mediate the stimuli.
Outline what happens when a receptor cell detects an electric signal, and what happens.
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
How would you design an experiment with which you could demonstrate whether a fish has the capacity of electroreception or not?
By isolating the sense (slide 15)
What kind of behaviours are associated with electroreception?
Prey detection, predator avoidance, intraspecific communication, object avoidance, geomagnetic navigation
Describe the difference between passive and active electroreception.
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
Describe the difference of capacitance and resistance.
Capacitance: the ability of an object to store an electric charge
Resistance: the difficulity with which to pass an electric current through a conductor
Describe the difference between a conductor and a non-conductor.
COnductor: concentrates signal, easierly passed through
Non-conductor: spreads the signal away from object
What are the different properties of organic vs non-organic objects?
Organic: high capacitance, low resistance
Non-organic: low capacitance, high resistance
What cells sense the wave-form distortance?
Beta-cells
What is the novelty response?
Environmental stimuli cause increased frequency of EODs –> higher temporal resolution
What kind of information can be formed off of the slope-amplitude ratio?
Location and distance (analogi: sharpness of shadow enhances the closer the object is)
