Consciousness animal

Griffiths, R., Lewis, A., Jeffrey, P., Models for drug absorption in situ and in conscious animals, in Models for Assessing Drug Absorption and Metabolism. Borchard, R. T., Smith, P. L., Wilson, G. (eds), Plenum Press, New York, 1996, pp. 67-84. 

Measurement of rate and relative tidal volume in conscious animals Pulmonary function... 

Consciousness has to do with energy and light. It is really very simple. Neither animals nor people have consciousness. It is plants that have consciousness. Animals get consciousness by eating plants. 

Physiological change This could be measured in the whole conscious animal as, for example, a change in blood pressure, in temperature, or in a response to a particular stimulus. 

Additionally, cardiac function can also be modulated by centrally-located H3-receptors. The intracerebroventricular administration of (R)a-methylhistamine in conscious animals is associated with a marked reduction of the heart rate, an effect which is antagonised by thioperamide (McLeod et al., 1991). The peripheral administration of ipratropium, a muscarinic antagonist which does not cross the blood-brain barrier, prevents such inhibition, demonstrating that the activation of centrally-located histamine H3-receptors leads to an increase in the vagal tone to the heart, rather than to a facilitatory effect on the sympathetic efferent fibers. 

Conscious animal CNS Heart rate inhibition McLeod et al., 1991... 

In summary, despite the preference for studies in conscious animals stated in the ICHS7A guideline, the use of anesthetized animals for assessing cardiovascular effects of drags is a valid and useful approach with a variety of practical advantages in comparison to conscious animals. 

Clearance procedures can be conducted in all laboratory animal species anesthetized and conscious animal models may be used. Measurement of arterial pressure is advisable, especially in anesthetized preparations, to insure that renal perfusion pressure remains within the autoregulatory range (usually 80-120 mmHg). Vascular access ports can be helpful to provide continuous arterial access for pressure measurements (Mann et al. 1987). 

Fig. 3. Drawing of a rat showing placement of the pressure sensitive subpleural catheter and radiotelemetry transmitter for chronic measurement of pleural pressure in conscious animals. The enlargement is a cross-section through the esophagus showing the position of the catheter between the serosal and muscularis layers.

Guan et al. (1990) inserted two separate cannulas for bile and pancreatic juice to rats under methoxyfluorane anesthesia. Both fluids were returned to the intestine. Placing the rats in modified Bollman-type restraint cages, experiments could be performed after a few days in conscious animals. 

So far the discussion of firing patterns of the cells have been restricted to those seen in the most common preparations but the function of dopamine is surely best studied in conscious animals able to move and respond to external cues. In the past decade such recordings have begun to paint a very intriguing picture of the role of dopamine cells in animal behavior. Early studies of this type had been disappointing from the point of view of the involvement of dopamine cells in motor behavior. In cats (Trulson and Jacobs, 1979 Trulson, 1985) and monkeys (Schultz, 1986) it seemed that the dopamine cells were not responsive to the present behavior of the animal. Few, if any, the cells responded either to the movements in a motor task or to the sensory cues guiding the behavior. 

Direct measurement of blood pressure requires insertion of a cannula into an artery and generally a vein, respectively, to allow blood pressure and heart rate to be monitored, and also the administration of drugs. The animal is allowed to recover from anaesthesia, and the cardiovascular parameters are monitored in the conscious animal via the arterial cannula. 

A recent review [73] describes the various animal models used to mimic the different aspects of this disease. For KCAs, the in vivo models employed have generally been bronchoconstrictor in nature, where test compounds have been examined for their ability to prevent or reverse an induced bronchoconstriction. This can be achieved in several ways, the simplest being the respiratory embarrassment model, where a guinea-pig is exposed to a concentration of a bronchoconstrictor that causes dyspnoea. The KCAs may be tested by the oral route for their ability to attenuate the onset of dyspnoea. Even in the control animals, in which dyspnoea leads to rapid collapse, removal of the animals from the chamber and away from the bronchoconstrictor agent, allows a full recovery [74]. Various other ways of inducing bronchoconstriction in conscious animals are available, one of the... 

These experiments are performed in conscious animals, and no effect on other parameters such as blood pressure and heart rate can be monitored unless the animals are anaesthetized. However, the use of anaesthetics can reduce the blood pressure and inhibit neurogenic reflexes, thus masking any changes in cardiovascular parameters. Nevertheless, by careful comparison with standard drugs, relative falls in blood pressure can be assessed between compounds. 

In conscious animals Nonrodent in vivo telemetry studies (dogs, monkeys)... 

There are two general models for evaluating the nephrotoxic potential of chemicals that utilize whole animals. In one model, conscious animals are administered the test compound and renal functional parameters (Table 2) evaluated over a period of hours or days. Some of the urinary parameters routinely monitored using in vivo nephrotoxicity studies include volume, osmolality, and contents. Urine volume can increase (polyuria), decrease (oliguria), or approach a zero value (anuria). Urinary osmolality is a measure of the ability of the kidney to concentrate urine. In polyuric states, urinary osmolality usually decreases from control levels, while in oliguric states urine tends to be more concentrated and urinary osmolality values rise above the control level. 

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