When an individual has allergies it causes excess mucus to be produced in the nasal passages and sinus cavities. This excess of mucus cannot drain correctly and effectively out the nasal passages at times and as a result, the mucus containing foreign particles flows down the back of the throat, causing post nasal drip.
They transmit signals across a chemical synapse, such as in a neuromuscular junction, from one neuron (nerve cell) to another target neuron, muscle cell, or gland cell. Neurotransmitters are released from synaptic vesicles in synapses into the synaptic cleft, where they are received by receptors on other synapses.
Neurotransmitters are molecules that nerve cells, or neurons, use to communicate. When electrically stimulated, the transmitting, or prensynatptic, neuron releases neurotransmitters into the gap, called a synapse, between itself and an adjacent neuron.hey are distinguished from inhibitory neurotransmitters, which make an action potential in the cell less likely. The most common excitatory neurotransmitter in all vertebrates, including human beings, is called glutamate.