Aversive substances

The urine of a dominant male rat or mouse contains an aversive substance which is absent in the urine of subordinate animal (ff 9). Castrated male rat urine also lacks the aversive substance which may be restored after treatment with androgen (365). 

In research and clinical treatment of substance use disorders, pharmacotherapy and psychotherapy are frequently combined. Medication is often used as a maintenance drug, to reduce cravings or intoxication, or to produce aversion to a substance, while the focus of psychotherapy may be to encourage abstinence, teach the patient new coping skills, or improve motivation to address drug or alcohol problems. 

The active ingredients in a shampoo play three fundamental roles. Some allow water to wash away the substances that make hair dirty. Others adhere to hair to impart a desirable feel and texture. The rest are emulsifiers that keep the mixture from separating into its components. To accomplish these effects, ingredients combine two types of interactions a strong attraction to water (hydrophilic) and an aversion to water (hydrophobic). It may seem that these properties are incompatible, but shampoos contain molecules that are designed to be simultaneously hydrophilic and hydrophobic. One example is sodium lauryl sulfate, our inset molecule. The ionic head of the molecule is hydrophilic, so it interacts attractively with water. The hydrocarbon tail is hydrophobic, so it interacts attractively with grease and dirt. Molecules of the shampoo associate with hydrophobic dirt particles to form hydrophilic clumps that dissolve in water and wash away. 

Nicotine is an addictive substance with rewarding and reinforcing properties. On the other hand, the autonomic responses following an acute nicotine treatment and the bitter taste of nicotine may cause aversion. This aversion may impact conditioned effects to nicotme. Rinker et al. (2008) studied possible sex differences in taste aversion mduced by nicotine in rats systemic nicotine or saline injections were paired wim oral saccharine. Although nicotme did produce a weak taste aversion, no sex differences were observed, excluding the possible contribution of the aversive properties of nicotine on sexually dimorphic responses to nicotine. The authors conclude that sex differences may arise from differences in the rewardmg properties of the drug. 

Attempts to label dangerous substances with either characteristic or outright unpleasant odors have not been successful with children, the primary victims of accidental poisonings by toxic household products. Children tolerate odors that adults find unpleasant, such as that of butyric acid. The range between the most pleasant and unpleasant odors is much narrower for children around 4years of age than for adults, and also much narrower than for taste stimuli. This means that olfactory cues are not suited to produce aversive responses in children (Engen, 1974b, Cain, 1978). 

PUNISHMENTS Positive aversion hunger, thirst pain, fear/panic craving acetylcholine serotonin noradrenaline substance P glutamate... 

Conditioned taste aversion. Erozen leaf and stem, administered intragastrically to rats at a dose of 562 mg/kg, was inactive. The test substance was temporarily paired with the introduction of sodium saccharin... 

The aversive agents diminish substance use by producing an aversive reaction when a specihc illicit substance is consumed. For example, disulfiram (Antabuse) prevents the breakdown of acetaldehyde, a toxic metabolite of alcohol, producing a noxious reaction when alcohol is consumed. While aversive agents have been in existence for decades, studies of their effectiveness in adults have produced mixed results (Kaminer, 1994b Garbutt et al., 1999). Likewise, there is only one published case report on the use of aversive therapy for pediatric SUD. Myers and associates (1994) reported on the use of disulfiram (Antabuse) for two teens with alcohol dependence. Both patients were briefly abstinent, but then became noncompliant and quickly relapsed. 

Okano, K., Kuraishi, Y., Satoh, M. Pharmacological evidence for involvement of excitatory amino acids in aversive responses induced by intrathecal substance P in rats, Biol. Pharm. Bull. 

In order to test whether some substance affects neurobehavioral development, it is necessary to choose tests which in principle cover the whole behavioral repertoire of the animal at different stages of development. Tests should be performed of reflex- or neuromotor development, sensory functioning, activity, emotionality, exploration, motivation and attention, as well as learning (appetitive and aversive learning in simple and complex... 

When larvae fail to settle in a particular test situation, is it due to the absence of positive cues, or are there other factors that prohibit settlement, even when positive cues may be present This is a difficult question to answer because of the possibility that a negative cue may, in fact, be a neutral substance that simply makes the positive cue undetectable by a larva, rather than a substance that causes a larva to reject a potential settlement site. Much effort to demonstrate negative cues to settlement has come from the search for antifouling natural products from marine organisms (reviewed by Pawlik 3 see also Chapters 10 and 17 in this volume). However, there is little reason to believe that extracted compounds which are toxic or aversive to invertebrate larvae have any such function in nature. The best evidence to date for chemical deterrence of larval settlement comes from the work of Woodin and co-workers.212 214 Focusing on halogenated compounds released by many marine polychaete and enteropneust worms,212 they have shown inhibition of settlement of larvae of other species in the presence of the compounds.213 214... 

Another variant is the manner of administering the test substance. One of the interpretational problems with passive avoidance is the occurrence of other drug effects, for example on pain sensitivity or attention, which can confound the interpretation in terms of memory. Some of these effects can be controlled by administering the test substance immediately after Tl, with the intention of acting on so-called memory consolidation (Slotnick Jarvik 1966). Post-trial administration has other problems however. Administration of the test substance may have positive reinforcing or aversive effects which can influence the scores at T2. Another problem is their onset of action. A test substance with slow onset could miss the consolidation period altogether and thereby appear to be devoid of amnesic potential when this is not the... 

Further problems are encountered with substances such as THC, where place preference can be observed over a narrow range of low doses (0.5-1 mg/kg i.p.), but where place aversion is observed at higher doses (Maldonado and Rodriguez de Fonseca 2002). Conditioned place preference has been reported with nicotine, but only after a short pretreatment with nicotine before commencing place preference conditioning (Shoaib et al. 1994). We have been unable to replicate this finding in our own laboratory (our unpublished data). 

A learned behavior that is obviously of adaptive advantage to an animal is its ability to avoid a substance that it ingested shortly before the onset of an illness or adverse effect. This conditional taste aversion can be used to measure toxicity, for example, by pairing a novel taste (a sugar treat, for example) with administration of a toxicant. If the animal feels ill soon afterward, it will avoid the novel substance in the future. This technique has proved to be sensitive to the effects of neurotoxic agents. 

For consumers, a lack of transparency represents increased risk. Consumers aversion tea risk may thus result in sub-optimal demand for organic goods. Ideally, the quality of different products can be easily distinguished at the point of sale hy labelling (compare Darby and Karny 1973 Nelson 1970). Many regulations and labels therefore exist within the food market. Once the consumers have bought their food, they can experience characteristics like freshness or taste. Other characteristics are not immediately apparent, but are nonetheless important, such as the presence of undesirable substances which only affect health in the long run. These are called credence characteristics because consumers have to believe in these characteristics - there is no way to check for them. 

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