Environmental stimuli

Obviously, it is extremely unlikely that noradrenergic transmission is the sole factor to determine the behavioural response to even simple environmental stimuli. Indeed, a bell-shaped dose-response curve immediately suggests the intervention of one or more additional factors (neurotransmitters ). Such interactions with other neurotransmitters could well define the relationship between noradrenergic transmission and the coding of the coping response. 

McQuade, R and Stanford, SC (2000) A microdialysis study of the noradrenergic response in rat frontal cortex and hypothalamus to a conditioned cue for aversive, naturalistic environmental stimuli. Psychopharmacology 148 201-208. 

All preclinical animal models of anxiety involve exposing animals (usually rats or mice) to environmental stimuli that disrupt their normal pattern of behaviour (Table 19.2). Obviously, it can never be confirmed that animals are actually experiencing the equivalent of human anxiety and so the validity of all preclinical models rests largely on confirming that the change in behaviour is prevented by drugs that have established anti-anxiety effects in humans. 

An influential theory proposed by Gray (1987) suggests that environmental stimuli that induce anxiety in both rats and humans fall into three major groups, all of which present threats to the individual. One of these is novelty in which the subject s innate... 

Table 19.2 Environmental stimuli that induce changes in behaviour which are prevented by anti-anxiety drugs...

Dailey, JW, Mason, K and Stanford, SC (1996) Increased levels of extracellular noradrenaline in the frontal cortex of rats exposed to naturalistic environmental stimuli modulation by acute systemic administration of diazepam or buspirone. Psychopharmacology 127 47-54. 

It is well known that survival and proliferation of microbial cells in the environment depend on the expression of advantageous phenotypes controlled by the genotype expression. It is becoming clear that such evolutionary pressure has resulted in a network of sensor mechanisms that transduce environmental stimuli into gene expression and hence a phenotype complementary to the prevail-... 

Finally, the networks of protein-protein interactions defined by these studies provide a global view of how cellular processes are coordinated. As described below, protein interaction networks from S. cerevisiae indicate that interactions occur not only between proteins involved in certain cellular processes but also between proteins involved in different processes. These links may be crucial for sharing information and thereby coordinating global responses to environmental stimuli. 

Caggiula, A.R., Donny, E.C., White, A.R. et al. Environmental stimuli promote the acquisition of nicotine self-administration in rats. Psychopharmacology (Berlin). 163 230, 2002. 

Shape-memory polymers (SMPs) are a class of smart materials with the ability to change shape on demand in response to an environmental stimuli [322-325]. So far, the most commonly investigated SMPs are temperature-induced SMPs, whose shape-recovery behavior is triggered by thermal stimuli. Such SMPs have one shape at certain temperature and are converted to another shape at a different temperature (Fig. 22). Temperature-responsive SMPs usually require the combination... 

Radiation is one of the most important known environmental stimuli of cancer development. This environmental factor becomes especially dangerous for humans living in the areas affected by irradiation from nuclear accidents. Earlier we found that the administration of a mixture of vitamin E and a-lipoic acid to children living in the area of Chernobyl nuclear accident significantly and synergistically suppressed leukocyte oxygen radical overproduction [211]. Thus a-lipoic acid and a-lipoic acid + vitamin E supplements may be of interest as antioxidant preventive agents for the treatment of radiation-induced cancer development. 

Cruz, N. F. and Dienel, G. A. High glycogen levels in brains of rats with minimal environmental stimuli implications for metabolic contributions of working astrocytes. J. Cereb. Blood Flow Metab. 22 1476-1489, 2002. 

Several investigators have shown that many of the physiological and behavioral effects of opioids can be conditioned. For example, environmental stimuli that have been paired with morphine administration can elicit morphine-like effects, such as hyperthermia, when presented in the absence of morphine [76-79], In line with these studies, our laboratory provided the first demonstration that alterations of immune status can be conditioned to environmental stimuli that have been paired with morphine administration [80-82], In that investigation, rats received subcutaneous injections of morphine in a distinctive environment. When rats subsequently were re-exposed to the distinctive... 

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