Pharmacodynamics receptor desensitization

Desensitization describes the rapid signal attenuation in response to stimulation of cells by receptor agonists. Changes in the coupling efficiency of receptors to signal transduction pathways and receptor internalization can account for desensitization and the development of pharmacodynamic tolerance. 

Postsynaptic regulation can be considered from two perspectives modulation by the prior history of activity at the primary receptor (which may up- or down-regulate receptor number or desensitize receptors see Chapter 2 Drug Receptors Pharmacodynamics) and modulation by other temporally associated events. 

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