If Dopamine and Dopamine D2 receptor is involved in craving, wanting and clinging towards something or incentive salience
Dopamine is closely associated with reward-seeking behaviors, such as approach, consumption, and addiction. Recent researches suggest that the firing of dopaminergic neurons is a motivational substance as a consequence of reward-anticipation. This hypothesis is based on the evidence that, when a reward is greater than expected, the firing of certain dopaminergic neurons increases, which consequently increases desire or motivation towards the reward (from dopamine on Wikipedia )
What is the opposite mechanism in humans - by which we are experiencing aversion from something?
For example, someone finds something rotten, stinky and covered in white fuzzy mold in a plastic bag. Eww! Gross! Get it away! don't touch it! Keep distance. What is neurologically responsible for the person's feeling of aversion towards an object like that?
Are there different pathways to aversion?
For example, would seeing a person who looks like a witch from fairy tales (old, ugly, rotten teeth, lots of warts, body odor) cause the same aversion response as moldy food?