Symptoms of insect bites and stings. An insect bite or sting often causes a small lump to develop, which is usually very itchy. A small hole, or the sting itself, may also be visible. The lump may have an inflamed (red and swollen) area around it that may be filled with fluid. This is called a weal.
Hormones and the Brain. That's not to say estrogen isn't a major player in regulating moods. Estrogen acts everywhere in the body, including the parts of the brain that control emotion. Some of estrogen's effects include: 1  Increasing serotonin, and the number of serotonin receptors in the brain.
1 In both men and women, the same part of the brain that regulates sleep-wake hormones (such as melatonin and cortisol) also triggers daily release of reproductive hormones.  The hormones that trigger ovulation in women and the sperm-maturation process in men may be tied into the body's sleep-wake patterns.