neuro questions!

[yj90]

Whole-cell patch clamp electrophysiology can be used to record:
a) the activity of the ion channels that are present in the patch of membrane
b) the activity of multiple neurons at a given time
c) voltage and/or current across the membrane of a cell
d) multi-unit activity

My guess: c.

Sensory adaptation:
a) only occurs at phasic receptors
b) only occurs at tonic receptors
c) is due to a change in the quantitative way that a receptor encodes stimuli
d) is independent of receptors

My guess: c.
for this question... is it fair to say that adaptation only happens in phasic receptors? for tonic receptors, there is continuous response... but there is still some adaptation later on...? I'm quite confused about this question...

Please help with these two questions!

Thank you~

[JackBean]

1) agree
2) no idea

[daniel.kurz]

The answer is phasic receptor for number 2. I agree with A on number 1. The reason for number 2 is simply that it uses a system like binary code of either the stimulus is there or not there. Aka either 1 (there) or 0 (not there). These are used to sense pressure, pain, and other sudden things. Phasic is not discriminate as to the quality of a stimulus but only to the quantity. When something hurts more its because of more phasic receptors firing. Tonic receptors tell us more about the quality and often we refer to them in muscle physiology.