The Central Connections of Area Postrema Define the Paraventricular System Involved in Antinoxious Behaviors
John Kucharczyk, David J. Stewart, Alan D. Miller in Nausea and Vomiting: Recent Research and Clinical Advances, 2017
Not all animals vomit. In animals incapable of vomiting, equivalent protection against the ingestion of noxious substances is achieved by conditioned taste aversion and by signaling distaste to conspecifics. Ingestion of unpalatable food evokes gaping, chin rubbing, head shaking, paw wiping, forelimb flailing,67 inactivity, salivation, and gagging, signals that are presumably utilized by conspecifics as warning signs. When accompanied by such signs of distaste, conditioned taste aversion may serve as an animal model of nausea,62 although caution is indicated in equating the two.68 When unconditioned stimuli such as lithium chloride (causing upper GI discomfort) are used to condition taste aversion, the conditioned stimuli acquire the capacity to evoke signs of distaste.69 In other words, appropriate stimuli paired with nausea become nauseating themselves, and this may mediate the aversion that prevents their ingestion.
Chemosensation to Enhance Nutritional Intake in Cancer Patients
Alan R. Hirsch in Nutrition and Sensation, 2023
For patients who have already developed a taste aversion, behavioral strategies should help reverse this learned process. Systematic desensitization, originally proposed by psychiatrist Joseph Wolpe, is a behavioral intervention commonly utilized by mental health professionals when helping cancer patients alter an aversive reaction to otherwise neutral stimuli (in this case food) that has been linked with unpleasant side-effects of cancer treatments (such as nausea) (Lotfi-Jam, Carey, Jefford, Schofield, Charleson, and Aranda 2008;Redd, Montgomery, and DuHamel 2001). In systematic desensitization, the trained clinician develops with the patient a hierarchy of aversive stimuli (from least aversive to most aversive), and gradually introduces these events while the patient is in a calm and relaxed state. The introduction of the aversive stimuli can be done “in vivo” (where the actual stimulus is presented to the patient) or imagined (by asking the patient to evoke the stimulus through memory). Repeated exposure to the aversive stimulus during a calm and relaxed state eventually leads the aversion to cease or become extinct. Systematic desensitization is a strategy that requires careful planning and execution, and should only be performed by trained professionals (Roscoe, O’Neill, Jean-Pierre et al. 2010).
Brain Immune Pathways Regulating Immunological Function and Conditioned Immune Responses
Husband Alan J. in Behaviour and Immunity, 2019
The most popular conditioning procedure that has been applied to the modification of immune function is the taste aversion model. The pairing of taste with different illness-inducing agents results in an avoidance of the solution containing the novel taste (e.g. saccharin). Pairing with LiCl also produces conditioned taste aversion.24 Most experiments on taste aversion learning have used an immunosuppressive drug, cyclophosphamide, and shown that the re-exposure to the taste cue re-elicits the immunosuppressive response. Using this model, conditioned immunosuppression has been observed for antibody responses17 and CTL induction.25 The taste aversion model has recently been used to condition the release of mast cell specific proteases.19 These conditioned responses appear to have biological significance and can alter the outcome of autoimmune disease in NZB mice,17 GVH disease,26 and tumor immunity.18
Effects of caloric or non-caloric sweetener long-term consumption on taste preferences and new aversive learning
Published in Nutritional Neuroscience, 2020
Gabriela Vera-Rivera, María-Isabel Miranda, José Alejandro Rangel-Hernández, Dennys Badillo-Juárez, Daniela Fregoso-Urrutia, Seraid Caynas-Rojas
Recent evidence in rodents indicates that consumption of artificial sweeteners, in which sweet taste is dissociated from normal caloric consequences, could induce changes in energy and body weight regulation.3 The disruption of energy regulation by sweeteners suggests that flavors, including all the orosensory cues, not only modify intake and appetitive behavior but also change learned and conditioned responses.4 Flavor-conditioned responses prepare the gastrointestinal tract for the arrival of nutrients and mediate the anticipation of food reward; specifically, a Pavlovian conditioning occurs when taste (e.g. sweet, bitter) becomes a conditioned stimulus (CS) for post-ingestive (e.g. nutritive, gastric malaise) unconditioned stimulus (US). As a result, taste CS evoke conditioned responses. An appetitive response may develop if the taste is nutritive and palatable, increasing taste consumption,5 or an aversion to a certain taste is acquired when its consumption is followed by gastric malaise, i.e. conditioned taste aversion (CTA).6
The role of placebo effects in immune-related conditions: mechanisms and clinical considerations
Published in Expert Review of Clinical Immunology, 2018
Rosanne M. Smits, Dieuwke S. Veldhuijzen, Nico M. Wulffraat, Andrea W. M. Evers
On a central level, excitotoxic lesions (nerve damage systematically induced by overstimulation) performed before and after acquisition trials demonstrated the involvement of the insular cortex, amygdala, and ventromedial nucleus of the hypothalamus (VMH). The insular cortex seems to play an associative role in the acquisition and evocation of learned immune responses and may be responsible for conditioned taste aversion as lesions of the amygdala and VMH did not affect this behavior. Subsequently, the amygdala was found to mediate visceral input necessary for associative learning and the VMH might play a role in communication between the brain and immune system necessary to evoke a learned immune response [62]. On the other hand, the afferent pathways that cause the CNS to detect changes in the peripheral immune system induced by an inert substance are not completely understood, as it is still unclear which messengers activate the brain during the acquisition trials [59].
Risks of cognitive detriments after low dose heavy ion and proton exposures
Published in International Journal of Radiation Biology, 2019
Francis A. Cucinotta, Eliedonna Cacao
A major focus of space CNS radiobiology has been studies employing cognitive tests in mice and rats. The extrapolation of these results to humans has not been established, while issues of use of higher doses and dose-rates compared to those that occur in space has not been adequately addressed. Studies are diverse utilizing a variety of cognitive tests, doses, particle types, sex, age at exposure and time after exposure. These studies indicate significant deficits will occur at doses of 0.5 Gy and higher of high charge and energy (HZE) particles, while both positive and negative results were reported at lower doses. Particle species most often used in experiments are Fe, H, O, Ti and Si. Rabin et al. (2007, 2011) has been the only investigator that has detailed dose responses with 3 or more doses per cognitive test. Therefore information on dose thresholds in rodents has not been reliably established. No studies have been made for a chronic exposure or for the complex radiation field that occurs in space (Kim et al. 2015). Cognitive detriments suggested by various studies suggest the striatum, hippocampus, and the pre-frontal cortex are impacted. Older studies by Joseph and collaborators (see e.g. Rabin et al. 1991, 2000; Joseph et al. 1992) of sensorimotor deficits, conditioned taste aversion, and fixed operant responses were reviewed earlier by Cucinotta et al. (2014) showing differential results for heavy ion doses below 1 Gy.
Related Knowledge Centers
- Acetaldehyde
- Adaptation
- Alcoholism
- Aldehyde Dehydrogenase
- Cephalosporin
- Disulfiram
- Latent Inhibition
- Taste
- Sushi
- Hangover