The atmosphere is quite dusty, giving the Martian sky a light brown or orange-red color when seen from the surface; data from the Mars Exploration Rovers indicate that suspended dust particles of roughly 1.5 micrometres diameter.
Glutamate is a powerful excitatory neurotransmitter that is released by nerve cells in the brain. It is responsible for sending signals between nerve cells, and under normal conditions it plays an important role in learning and memory.
Glutamate. Glutamate is the most abundant excitatory neurotransmitter in the brain and spinal cord. It is released, for example, by afferent neurons. In many cases, the receptor is a ligand gated ion channel that produces fast postsynaptic potentials.cetylcholine. Acetylcholine is the neurotransmitter released by two types of neurons you hear about frequently in physiology: parasympathetic postganglionic neurons and somatic efferent neurons. In the parasympathetic case, the receptor is a seven transmembrane domain receptor coupled to a trimeric G protein.