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.
In a typical chemical synapse between two neurons, the neuron from which the nerve impulse arrives is called the presynaptic neuron. The neuron to which the neurotransmitters (chemical messengers) bind is called the postsynaptic neuron. A presynaptic neuron has several specialized structures that distinguish it from a postsynaptic neuron.