Avoidance behaviors

Approach behavior Avoidance behavior Detour learning... 

Heinz G. 1975. Effects of methyhnercury on approach and avoidance behavior of mallard ducklings. Bull Environ Contam Toxicol 13 554-564. 

Webber HM, Haines TA. 2003. Mercury effects on predator avoidance behavior of a forage fish, golden shiner (Notemigonus ctysoleucas). Environ Toxicol Chem 22 1556-1561. 

Venlafaxine extended release, in doses of 75 to 225 mg/day, improves social anxiety, performance, and avoidance behavior with a reduction in disability.61 Treatment with venlafaxine results in response rates similar to those seen with paroxetine.60 Venlafaxine may be effective in SSRI non-responders.62 As with SSRIs, doses should be tapered slowly when discontinuing therapy. Tolerability is similar to that observed in depression trials with venlafaxine extended release. Common side effects are anorexia, dry mouth, nausea, insomnia, and sexual dysfunction. 

Gabapentin, a non-benzodiazapine GABA analog, was modestly effective in a 14-week controlled trial in SAD. Most patients were titrated to a maximal dose of 3600 mg/day.58 Pregabalin 600 mg/day was effective for social anxiety, fear, and avoidance behavior in a 10-week controlled trial.63 Pregabalin was well tolerated, and the most common side effects were somnolence and dizziness. 

How to record symptoms (e.g., fears, panic attacks, avoidance behaviors) and report back to their clinician. 

Detection of the hyperparasitoid by the primary parasitoid has also been recently described. The parasitoid Aphidius uzbekistanikus detects trans-fused iridoids 21 produced by females of the hyperparasitoid A. victrix as part of their defensive cephalic gland secretion. The iridoids cause avoidance behavior in A. uzbekistanikus [46]. 

Heinz, G.H. and S.D. Haseltine. 1983. Altered avoidance behavior of young black ducks fed cadmium. Environ. Toxicol. Chem. 2 419-421. 

Kononen, D.W., J.R. Hochstein, and R.K. Ringer. 1991. Mallard and northern bobwhite exposure to compound 1080 acute toxicity and food avoidance behavior. Chemosphere 22 655-663. 

Heinz, G.H. and M.T. Finley. 1978. Toxaphene does not effect avoidance behavior of young black ducks. Jour. Wildl. Manage. 42 408-409. 

Bufotenine has been found to be behaviorally inactive, or only weakly active, in most animal studies, although at 15 mg/kg, it did produce the head-twitch resonse in mice (43). It was also behaviorally active in experiments in which the blood-brain barrier was bypassed (78). Acylation of the polar hydroxy group of bufotenine increases its lipid solubility (65,74) and apparently enhances its ability to cross the blood-brain barrier (64). For example, O-acetylbufotenine (5-acetoxy-N,N-dimethyltryptamine 54) disrupted conditioned avoidance behavior in rodents (65) and produced tremorigenic activity similar to that elicited by DMT (37) or 5-OMeDMT (59) when administered to mice (64). In this latter study, a comparison of brain levels of bufotenine after administration of O-acetylbufotenine with those of DMT and 5-OMeDMT revealed bufotenine to be the most active of the three agents, based on brain concentration. The pivaloyl ester of bufotenine also appears to possess behavioral activity, since stimulus generalization was observed when this agent was administered to animals trained to discriminate 5-OMeDMT from saline (74). 

A positional isomer of harmaline, 6-methoxyharmalan (85), was found to be slightly more active than harmaline in disrupting conditioned avoidance behavior in rats (146). Gryglewski and co-workers (98) found that replacement of the 1-methyl group of 6-methoxytetrahydroharman (86) by aryl substituents diminished excitatory behavior and resulted in a series of agents that produced a generalized depressant effect. 

Vasko, M. R., Lutz, M. P., and Domino, E. F. (1974) Structure activity relations of some indolealkylamines in comparison to phenethylamines on motor activity and acquisition of avoidance behavior. Psychopharmacologia, 36 49-58. 

Kohler, C., and Lorens, S. A. (1978) Open field activity and avoidance behavior following serotonin depletion A comparison of the effects of parachlorophenylalanine and electrolytic midbrain raphe lesions. Pharmacol. Biochem. Behav., 8 223-233. 

Martin and co-workers (142,143) have found that, in animals, tryptamine produced many of the physiologic effects characteristic of LSD however, it does not appear to elicit behavioral effects similar to those of LSD. At relatively high doses, 5-methoxytryptamine (24) does produce some behavioral effects in rats (66,242) and in nonhuman primates (101). Vogel (242) has suggested that the disruptive effects of 5-methoxytryptamine might be due to the peripheral actions of this agent. Tryptamine had no effect on acquisition of avoidance behavior, whereas 5-methoxytryptamine slightly decreased such behavior (240). Both tryptamine and 5-methoxytryptamine produced discriminative effects in rats... 

N-Methyltryptamine (27) was found to have no effect on the acquisition of avoidance behavior (240). Brimblecombe (23) compared the behavioral effects of a series of N-monoalkyltryptamines and N,N-dialkyltryptamines using Hall s open-field test. Although there was no clear-cut structure-activity relationship,... 

Psilocin has also been the object of considerable investigation using animals as subjects. Much of the initial work with psilocin, as well as other 4-hydroxy-tryptamine derivatives with alterations in the side chain and/or terminal amine, was performed at Sandoz Laboratories in Switzerland (29,245). Subsequent investigations have shown that psilocin produces hyperthermia in rabbits (113), induces the head-twitch in mice (43), disrupts acquisition of avoidance behavior in rats (240), increases startle response magnitudes in rats (68), increases limb-flick behavior in cats (120), and produces discriminative stimulus effects in rats similar to those of 5-OMeDMT (59) (93). 

Neurological Effects. No studies were located regarding neurological effects in humans after exposure to hexachloroethane. Inhalation, oral, and dermal exposure of animals to moderate or high doses (260 ppm, 5,900 ppm, 375 mg/kg/day, 750 mg/kg/day) resulted in hyperactivity, tremors, fasciculation of the facial muscles, ataxia, convulsions, and/or prostration (Fowler 1969b NTP 1977, 1989 Southcott 1951 Weeks et al. 1979). Reduced motor activity has also been observed following oral exposure of pregnant rats (167 mg/kg/day) (Shimizu et al. 1992). Inhalation exposure of rats to 260 ppm for 6 weeks did not have any effect on spontaneous motor activity or shock avoidance behavior (Weeks et al. 1979). 

Neurotoxicity. No information is available on neurotoxic effects of hexachloroethane in humans following any route of exposure. Acute inhalation exposure in rats caused staggering gait after exposure to high concentrations (5,900 ppm) (Weeks et al. 1979). The usefulness of this data is limited since this concentration was lethal. Tremors have been reported at 260 ppm but not 48 ppm following inhalation exposure of rats in a developmental study and in a study of 6-weeks duration (Weeks et al. 1979). The lack of tremors at 48 ppm in the developmental study serves as the basis for the acute inhalation MRL, and the lack of tremors at 48 ppm in the 6-week study serves as the basis for the intermediate inhalation MRL. One study that evaluated spontaneous motor activity and avoidance behavior in rats during 6 weeks of exposure to 260 ppm hexachloroethane vapors did not reveal adverse effects of hexachloroethane on these neurobehavioral functions (Weeks et al. 1979). 

Three male squirrel monkeys previously trained to perform visual discrimination or visual acuity threshold tests were exposed continuously for 90 d to PGDN at a concentration of 262 mg/m3 (approximately 37 ppm) (Jones et al. 1972). The animals were removed from the exposure chambers for a 2-h period once a week for the respective behavior tests. A fourth trained monkey exposed to filtered room air under the same conditions served as the control. The only sign during exposure was mydriasis (excessive dilatation of the pupil of the eye), which increased from slight to moderate. There were no changes in avoidance behavior in the monkeys as determined by the visual tests. 

Few data on acute exposures with effects that meet the definition of an AEGL-2 were located. No clinical signs of intoxication were observed in rats exposed to PGDN at 189 ppm for 4 h. The methemoglobin level was 23.5% (Jones et al. 1972). Exposure of monkeys to PGDN at a concentration of 33 ppm for 4 h failed to affect performance in an operant avoidance behavioral test but altered the VER (Mattsson et al. 1981). 

When confronted with chemically rich seaweeds in their local communities, some herbivores have evolved a means to detect and avoid these foods. These feeding avoidance behaviors are probably mediated by taste, rather than smell, because... 

Ma TC, Yu QFI, Chen MFI. (1991). Effects of ginseng stem-leaves saponins on one-way avoidance behavior in rats. Chung Kuo Yao Li Hsueh Pao. 12(5) 403-6. 

As noted above, panic disorder is commonly accompanied by agoraphobia as avoidant behaviors develop in what are usually partially successful attempts to reduce the frequency and intensity of panic attacks. Estimates for the co-occurrence of agoraphobia in patients with panic disorder range from 30% to 50%. 

Post-traumatic Stress Disorder (PTSD). The same distinction holds true for PTSD. Reminders of the tranma (e.g., sexual intimacy for a rape survivor loud noises for a combat veteran) can trigger panic attacks. Furthermore, PTSD is associated with a variety of avoidant behaviors that can resemble agoraphobia. In the case of PTSD, the avoidance is specifically targeted at reminders of the trauma. For example, places or people who in some way cue memories of the traumatic event are avoided. As for agoraphobia, the avoidance tends to be less specific. It is any sitnation from which it would be difficult to escape should a panic attack occur that is avoided. 

An example for stimulus generalization are responses of rats to stress-inducing odors. Laboratoiy rats of the Wistar strain respond to predator odors, specifically mercapto compounds in fox droppings, with stress reactions, for example avoidance behavior such as freezing and increased plasma corticosterone concentrations (Vemet-Mauiy et ah, 1984). The rats were trained to avoid water scented with a mercapto odorant that contained both a keto- and a sulfhydryl group (4-mercapto-4-methyl-2-pentanone). As the animals licked a waterspout, a mild electric shock was applied to their tongue. When different compounds were tested thereafter, the rats avoided compounds with similar... 

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