Noun

(-)

(biochemistry, pharmacology) Extreme sensitivity (of the body) to a chemical.

*{{quote-journal, 1997, date=October 3, Eric J. Nestler & George K. Aghajanian, Molecular and Cellular Basis of Addiction, Science citation

, passage=Because D 1 dopamine receptors are known to act through stimulatory heterotrimeric guanosine triphosphate-binding (G s ) proteins and activation of the cAMP pathway, up-regulation of this pathway in the nucleus accumbens could account for the functional supersensitivity of D 1 receptors observed in these neurons--which occurs in the absence of detectable changes in the receptors themselves--after chronic cocaine (or other stimulant) exposure (18 ). }}

*{{quote-journal, 1998, date=October 9, Zhen-Ming Pei et al., Role of Farnesyltransferase in ABA Regulation of Guard Cell Anion Channels and Plant Water Loss, Science citation

, passage=In the next generation seeds were screened for ABA supersensitivity (era1/era1 ). }}

*{{quote-journal, 1999, date=October 15, Mohammed Akaaboune et al., Rapid and Reversible Effects of Activity on Acetylcholine Receptor Density at the Neuromuscular Junction in Vivo, Science citation

, passage=The effects of inactivity on new receptor synthesis and denervation supersensitivity are mediated by Ca 2 influx (24 ). }}

Noun

The state or quality of being irritable; quick excitability; petulance; fretfulness; as, irritability of temper.

(physiology) A natural susceptibility, characteristic of all living organisms, tissues, and cells, to the influence of certain stimuli, response being manifested in a variety of ways.

* E. Darwin

We find a renitency in ourselves to ascribe life and irritability to the cold and motionless fibres of plants.

(medicine) A condition of morbid excitability of an organ or part of the body; undue susceptibility to the influence of stimuli.