Stimulus-response specificity

Stimulus-response specificity is a concept describing conditions where a very specific response can be predicted with tremendous regularity when a stimulus is applied. One example would be that an electrical shock to muscle tissue evokes a contraction. This model is appropriate for some types of medical interventions. For example, for acute cardiac and respiratory arrest, the techniques of cardiopulmonary resuscitation (CPR) can be used with most victims, regardless of their age, socioeconomic status, sex, or religious beliefs. When there is an obstructed airway, performing an emergency tracheotomy is appropriate for victims regardless of their emotional status, personality style, or level of psychosocial maturity. Likewise, some medications have fairly universal effects on all people for instance, sodium pentothal produces unconsciousness (Deckert 1985). 

Medical treatments in psychiatry generally do not follow the rule of stimulus-response specificity. Although the particular mechanism of drug action may be identified, the same medication given to two depressed patients, for example, may affect them very differently. Some of these differences may be traced to variations in metabolism from individual to individual (see chapter 3). Or the underlying biochemical abnormality in one depressed patient may be different than the abnormality in another depressed patient, and thus the medications affect different underlying disorders. 

Unfortunately, in many overcrowded mental health clinics, some clinicians act as if stimulus-response specificity is appropriate. The result is that often these attempts at treatment efficiency and cost containment backfire. Many patients don t respond well and either must demand further outpatient services or continue to decompensate until they require hospitalization. And, of course, there is the human cost associated with prolonged suffering. 

When medications are given, especially if they are offered or recommended early on in treatment, many clients perception is "They just want to drug me. They don t want to talk. .. They don t want to hear my pain." Patients may feel they are being treated as a "case" (as in stimulus-response specificity) and the result can be a serious warp in the developing therapeutic alliance or even premature termination of therapy. 

The ability to reduce stimulus-response mechanisms to single mono tonic functions allows relative cellular response to yield receptor-specific drug parameters. 

The operational model, as presented, shows dose-response curves with slopes of unity. This pertains specifically only to stimulus-response cascades where there is no cooperativity and the relationship between stimulus ([AR] complex) and overall response is controlled by a hyperbolic function with slope = 1. In practice, it is known that there are experimental dose-response curves with slopes that are not equal to unity and there is no a priori reason for there not to be cooperativity in the stimulus-response process. To accommodate the fitting of real data (with slopes not equal to unity) and the occurrence of stimulus-response cooperativity, a form of the operational model equation can be used with a variable slope (see Section 3.13.4) ... 

There are a number of assay formats available to test drugs in a functional mode. As discussed in Chapter 2, a main theme throughout the various stimulus-response cascades found in cells is the amplification of receptor stimulus occurring as a function of the distance, in biochemical steps and reactions, away from the initial receptor event. Specifically, the further down the stimulus-... 

By utilizing complete dose-response curves, the method devised by Barlow, Scott, and Stephenson [9] can be used to measure the affinity of a partial agonist. Using null procedures, the effects of stimulus-response mechanisms are neutralized and receptor-specific effects of agonists are isolated. This method, based on classical or operational receptor theory, depends on the concept of equiactive concentrations of drug. Under these circumstances, receptor stimuli can be equated since it is assumed that equal responses emanate from equal stimuli in any given system. An example of this procedure is given in Section 12.2.1. 

In a more general way, the two major driving forces for the design of novel micellar systems are the control over morphology (spheres, vesicles, rods, tubules etc. with controlled size) and function (stimulus-responsive materials, biological functions). Both of these aspects are intimately related since a given morphology can induce a specific function. 

Protein phosphorylation alters protein ligand binding and/or catalytic functions and hence specific cellular processes, this representing the cellular response to the stimulus of the original primary messenger . The signalling system must be reversible and the protein phosphorylation step of the stimulus-response pathway is reversed through the action of phosphoprotein phosphatases (PPs), which are phosphohydrolases that catalyse the hydrolytic dephosphorylation of proteins ... 

Pieretti S, EH Giannuario A, De Felice M, Penetti M, Qrino G (2004) Stimulus-dependent specificity for annexin 1 inhibition of the inflammatory nociceptive response the involvement of the receptor for formylated peptides. Pain 109 52-63 Pilcher WH, Joseph SA, Mcdonald JV (1988) Immunocytochemical localization of proopiomelanocortin neurons in human-brain areas subserving stimulation analgesia. J Neurosurg 68 621-629... 

Intelligent molecular systems can be created based on host-guest recognition, which can self-organize and behave differently than nonorganized matter. Supramolecular structures formed by molecular recognition can be used to create molecular systems with specific functions, such as motors or stimulus-responsive... 

The operational model, as presented, shows dose-response curves with slopes of unity. This pertains specifically only to stimulus-response cascades where there is no cooperativity and the relationship between stimulus ([AR] complex) and overall response is controlled by a hyperbolic function with slope = 1. In practice, it is known that there... 

There is no specific reason for an allosteric modulator to completely inhibit receptor activation. Receptor function may partially be modulated (1 < > 0) or even increased ( , > 1). To consider an increase in efficacy first, on the surface it might be expected that an increase in efficacy would result in an increase in the maximal response, and in systems where the agonists are not full agonists (stimulus does not saturate the stimulus-response capability of... 

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