why disgust matters

Royal Society | The new synthesis about disgust is that it is a system that evolved to motivate infectious disease avoidance. There are vital practical and intellectual reasons why we need to understand disgust better. Practically, disgust can be harnessed to combat the behavioural causes of infectious and chronic disease such as diarrhoeal disease, pandemic flu and smoking. Disgust is also a source of much human suffering; it plays an underappreciated role in anxieties and phobias such as obsessive compulsive disorder, social phobia and post-traumatic stress syndromes; it is a hidden cost of many occupations such as caring for the sick and dealing with wastes, and self-directed disgust afflicts the lives of many, such as the obese and fistula patients. Disgust is used and abused in society, being both a force for social cohesion and a cause of prejudice and stigmatization of out-groups. This paper argues that a better understanding of disgust, using the new synthesis, offers practical lessons that can enhance human flourishing. Disgust also provides a model system for the study of emotion, one of the most important issues facing the brain and behavioural sciences today.

that explains my weakness for flawless mature women...,

Video - Catherine Deneuve conveying the sweet scent of Chanel No. 5.

ScienceDirect | Rats can display a conditioned partner preference for individuals that bear an odor previosuly associated with sexual reward. Herein we tested the possibility that odors associated with the reward induced by social play in prepubescent rats would induce a conditioned partner preference in adulthood. Two groups of 31-day-old, single-housed female rats were formed, and were given daily 30-min periods of social play with scented females. In one group, almond scent was paired with juvenile play during conditioning trials, whereas lemon scent functioned as a novel odor in the final test. The counterbalanced group received the opposite association. At age 42, females were tested for play partner preference with two males, one almond-scented and one lemon-scented. In both groups females displayed a play partner preference only for males scented with the paired odor. They were ovariectomized, hormone-primed, and at age 55 were tested for sexual partner preference with two scented stud males. Females displayed a sexual preference towards males scented with the paired odor as observed with more visits, solicitations, hops & darts, intromissions and ejaculations. These results indicate that olfactory stimuli paired with juvenile play affects later partner choice for play as well as for sex in female rats.

Highlights

► Neutral odors paired with juvenile play induce an olfactory conditioned play partner preference in prepubescent female rats ► The same conditioned odors (CS+) induce conditioned sexual partner preference in adult female rats. ► Sexual partner preference is observed with more proceptive behaviors directed towards the CS + male, which responds with more mounts, intromissions and ejaculations. ► This conditioned preference may be strong enough to support assortative mating.

Keywords: sexual behavior; conditioning; reward; odors; play; partner preference; copulation

The experimental protocols in this study were approved by a committee of the graduate program in Neuroethology, Universidad Veracruzana Mexico, following the Official Mexican Standard NOM-062-ZOO-1999 (Technical Specifications for the Production, Care and Use of Laboratory Animals).

why it's hard to eat just one...,

Video - Burt Lahr as the potato chip devil.

MSNBC | It's hard to eat just one potato chip, and a new study may explain why.

Fatty foods like chips and fries trigger the body to produce chemicals much like those found in marijuana, researchers report today (July 4) in the journal Proceedings of the National Academy of Sciences (PNAS). These chemicals, called "endocannabinoids," are part of a cycle that keeps you coming back for just one more bite of cheese fries, the study found.

"This is the first demonstration that endocannabinoid signaling in the gut plays an important role in regulating fat intake," study researcher Daniele Piomelli, a professor of pharmacology at the University of California, Irvine, said in a statement.

Homemade marijuana chemicals
The study found that fat in the gut triggers the release of endocannabinoids in the brain, but the gray stuff between your ears isn't the only organ that makes natural marijuana-like chemicals. Human skin also makes the stuff. Skin cannabinoids may play the same role for us as they do for pot plants: Oily protection from the wind and sun.

Endocannabinoids are also known to influence appetite and the sense of taste, according to a 2009 study in PNAS, which explains the munchies people get when they smoke marijuana.

In the new study, Piomelli and her colleagues fitted rats with tubes that would drain the contents of their stomachs as they ate or drank. These stomach tubes allowed the researchers to tell whether fat was acting on the tongue, in which case they would see an endocannabinoid release even with the tubes implanted, or in the gut, in which case they wouldn't see the effect.

The rats got to sip on a health shake (vanilla Ensure), a sugar solution, a protein-rich liquid called peptone, or a high-fat beverage made of corn oil. Then researchers anesthetized and dissected the rats, rapidly freezing their organs for analysis.

For the love of fat
Tasting sugars and proteins didn't affect the release of the body's natural marijuana chemicals, the researchers found. But supping on fat did. The results showed that fat on the tongue triggers a signal to the brain, which then relays a message down to the gut via a nerve bundle called the vagus nerve. This message commands the production of endocannabinoids in the gut, which in turn drives a cascade of other signals all pushing the same message: Eat, eat, eat!

This message would have been helpful in the evolutionary history of mammals, Piomelli said. Fats are crucial to survival, and they were once hard to come by in the mammalian diet. But in today's world, where a convenience store full of junk food sits on every corner, our evolutionary love of fat easily backfires.

The findings suggest that by blocking the reception of endocannabinoid signals, medical researchers might be able to break the cycle that drives people to overeat fatty food. Blocking endocannabinoid receptors in the brain can cause anxiety and depression, Piomelli said, but a drug designed to target the gut might not trigger those negative side effects.

body malodours and their topical treatment agents

Wileyonline | Body odour, which encompasses axillary and foot odour, can communicate a strong non-verbal signal [1, 2]. These odours are often unnoticed by the offender because that person has specific anosmia [3]. As a result, the individual is embarrassed when alerted, and his or her self-confidence is compromised. The offensive body odour also has economical consequences stemming from the need to replace damaged/stained clothes and shoes [4, 5].

In contrast to clear findings in animals, the presence of human vomeronasal organs is still being debated. Clearly, the ability to appreciate underarm and foot odours depends solely on an individual’s evolutionary culture and perceptual development. However, the emission of odourless human pheromones has been reviewed and is becoming a popular discussion topic [6].

The human scent is genetically controlled and systemically influenced by dietary and medicinal intake, as well as the application of fragrance products [6–8]. Heavy sweating or hyperhidrosis, particularly at axillary sites, leads to unpleasant odours that cause social embarrassment and reduce self-confidence, especially among women. Hyperhidrosis results from the oversecretion of sweat. Because there is an excessive amount of water in which bacteria can grow, hyperhidrosis is often accompanied by bromhidrosis or osmidrosis or offensive body odour. Both conditions can be treated by topically applying anti-perspirant and deodourant products. Body odour treatment products are part of a multibillion dollar industry [9]. High levels of fragrance are often used in these products to mask malodour [10]. Surprisingly, there is little discussion of odour treatment products in the literature [6], in contrast to other personal care products [11, 12].

This review will summarize the chemical composition and formation of body odour, the use of anti-perspirant, deodourant and herbal products to treat body odour, and a new class of treatment agents that do not change the balance of the skin’s bacterial population.