Earwax of bacteria. Cerumen has been found to reduce the viability of a wide range of bacteria, including "Haemophilus influenzae", "Staphylococcus aureus", and many variants of "Escherichia coli", sometimes by as much as 99%. The growth of two fungi commonly present in otomycosis was also significantly inhibited by human cerumen. These antimicrobial properties are due principally to the presence of saturated fatty acids, lysozyme and, especially, to the slight acidity of cerumen (pH typically around 6.1 in normal individuals). Conversely, other research has found that cerumen can support microbial growth and some cerumen samples were found to have bacterial counts as
Substance P concept studies have not yet been persuasively elucidated. Substance P has been associated with the regulation of mood disorders, anxiety, stress, reinforcement, neurogenesis, respiratory rhythm, neurotoxicity, pain, and nociception. In 2014, it was found that substance P played a role in male fruit fly aggression. The vomiting center in the medulla called the Area Postrema, contains high concentrations of substance P and its receptor, in addition to other neurotransmitters such as choline, histamine, dopamine, serotonin, and opioids. Their activation stimulates the vomiting reflex. Different emetic pathways exist, and substance P/NK1R appears to be within the final common pathway to regulate