Receptor Cells
Tonic Receptors
Tonic receptors: fire continuously throughout stimulation, with increasing frequency at higher stimulus intensity (proportional transducers).
Phasic Receptors
Phasic receptors: are often active only during the onset or offset of a stimulus, they are most sensitive for changes in stimulus intensity.
Phasic-Tonic Receptors
Phasic-tonic : initially onset/offset, later proportional response. Very abundant type of receptor cell.

left: tonic
right: phasic
What does the sensitivity of receptor cells depend on?
- Detection threshold: properties of cell structures or a certain transduction molecule
- Amplification: chemical reaction cascades involving second messengers like cAMP
- Spontaneous activity: very weak stimuli are sufficient to enhance the response, no threshold
see also
Tags: neurobiology science
Superlink: 051 ☣Neurobiology 050 🧠Neuroscience
Source
Created: 25-07-24 10:00