N2 nicotinic receptors are found in the brain, plus the autonomic and parasympathetic nervous systems [1]. Different subunits make up these two types of nicotinic receptor, which is why we consider them separately. Muscarinic receptors have a different mechanism of action.
Your body weight can regularly fluctuate, but the persistent, unintentional loss of more than 5% of your weight over 6 to 12 months is usually a cause for concern. You should pay particular attention if you experience other symptoms, such as tiredness, loss of appetite and a change in your toilet habits.
The following medical conditions are some of the possible causes of Unintentional weight loss. There are likely to be other possible causes, so ask your doctor about your symptoms. 1  AIDS. 2  Amyloidosis. 3  Amyotrophic lateral sclerosis. 4  Folic acid deficiency anemia. 5  Pernicious anemia. 6  Bipolar disorder. 7  Cirrhosis.