Nicotinic receptor activation causes the opening of the channel formed by the receptor. This increases the Na+ movement into the target cell, leading to depolarization and generation of the action potential. This rapidly developing change, termed a fast EPSP, is illustrated in Figures 4.3, and 6.2.
And, anecdotally at least, they act as an overall stimulant, producing a titillating, awakening effect and increasing the acuity of the senses. Peppers, especially the hot capsicum (chili) peppers, produce a burning sensation on the skin and mucous membranes, including the inside of the mouth. For the uninitiated, a relatively mild hot pepper can seem intolerably strong and truly hot peppers may even cause blistering of the lips and palate.
The health effects of caffeine have been extensively studied. Caffeine competitively inhibits different adenosine receptors, thereby producing mild central nervous system stimulant effects. Short term side effects such as headache, nausea, and anxiety have been shown as symptoms of mild caffeine consumption.