Pregnant women suffering from the common cold can be reassured about the safety of short-term use of OTC cold medications. These drugs, however, should not be used indiscriminately or for extended periods of time. In addition, use should be confined to only those products that are appropriate for the symptoms.
Acetylcholine (ACh) is a common neurotransmitter secreted by a variety of neurons. It binds to two different receptors-Ionotropic (fast) nicotinic receptors and metabotropic (slow) muscarinic receptors. 1  role in central nervous system. 2  role in peripheral nervous system. 3  receptors and signaling. 4  agonists and antagonists.
The Midbrain (mesencephalon) The mesencephalon is the most superior part of the brainstem. It is divided into an anterior and a posterior section by the Aqueduct of Sylvius which connects the third and fourth ventricles. Motor tracts, including the fibers of the pyramidal system, pass downward on the midbrain's anterior surface.