Acetylcholine (ACh)
A neurotransmitter is a chemical or peptide in synapses usually between neurons, a neuron and muscle or a neuron and other organ which functions to transmit information to and … from and within the brain. They provide a signal to or from the brain to the neurons in the body in response to a stimulus such and being burned. The neurotransmitters send a signal to the brain that th … ere is pain and the brain sends back a signal to the muscles to move the hand away from the heat. The most abundant neurotransmitter in the body and the primary neurotransmitter between neurons and muscles. The stomach, spleen, bladder, liver, sweat glands, blood vessels, and heart are just some of the organs that this neurotransmitter controls.  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. GABA (gamma-aminobutyric acid) is an inhibitory neurotransmitter that is very widely distributed in the neurons of the cortex. GABA contributes to motor control, vision, and many other cortical functions. It also regulates anxiety. Neurotransmitters are endogenous chemicals that enable neurotransmission. 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 released into and diffused across the synaptic cleft, where they bind to specific receptors in the membrane on the postsynaptic side of the synapse. Most neurotransmitters are about the size of a single amino acid, however, some neurotransmitters may be the size of larger proteins or peptides. A photoreceptor cell is a specialized type of neuron found in the retina that is capable of phototransduction. The great biological importance of photoreceptors is that they convert light (visible electromagnetic radiation) into signals that can stimulate biological processes. The pineal and parapineal glands are photoreceptive in non-mammalian vertebrates, but not in mammals. Birds have photoactive cerebrospinal fluid (CSF)-contacting neurons within the paraventricular organ that respond to light in the absence of input from the eyes or neurotransmitters. 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.  However, a nerve impulse can also be transmitted from a sensory receptor cell to a neuron, or from a neuron to a set of muscles to make them contract, or from a neuron to an endocrine gland to make it secrete a hormone. In these last two cases, the connection points are called neuromuscular and neuroglandular junctions. GABA (gamma-aminobutyric acid) is an inhibitory neurotransmitter that is very widely distributed in the neurons of the cortex. GABA contributes to motor control, vision, and many other cortical functions. It also regulates anxiety. Electrical activity, neuronal secreted factors, and intercellular interactions can all stimulate the change of the neurotransmitter for a particular neuron, both in the fetus and the adult brain. What is most intriguing is that the postsynaptic neuron also changes the receptors. Adult rats showed a neurotransmitter switch when experimentally exposed to a long day (19 hours of day, five of night) and a short day (opposite 19 hours of dark, 5 of light). In the short day experience, dopamine neurons in the hippocampus increased and in the long day cycles the number of dopamine neurons decreased. Neuron is the main cell of the Nervous System. It is an electrical excitable cell that is responsible for the transmision of the nerve impulse. With it, they process (in the brain, ganglia and spinal cord) and transmit information. A human brain has 100.000 millions of neurons. The other type of cell is glia, which protects the former. Neurons have three main parts: 1  Cell body or Soma: it is the main part of the cell, the one that makes all metabolism and functions. 2  It is very similar to other body cells, except for the difference that neurons do not replicate. 3  Axon: it is the longest and most important part of the neuron, it transmit the impulse. The released neurotransmitter may then move across the synapse to be detected by and bind with receptors in the postsynaptic neuron. Binding of neurotransmitters may influence the postsynaptic neuron in either an inhibitory or excitatory way. Neurotransmitters are released into and diffused across the synaptic cleft, where they bind to specific receptors in the membrane on the postsynaptic side of the synapse. Most neurotransmitters are about the size of a single amino acid, however, some neurotransmitters may be the size of larger proteins or peptides.
http://www.answers.com/Q/What_secretes_neurotransmitters https://www-s.acm.illinois.edu/sigbio/project/nervous/micro_info/neuro.html http://thebrain.mcgill.ca/flash/i/i_01/i_01_m/i_01_m_ana/i_01_m_ana.html https://en.wikipedia.org/wiki/Neurotransmitter https://en.wikipedia.org/wiki/Photoreceptor_cell http://www.sharinginhealth.ca/biology/neurotransmitters.html http://thebrain.mcgill.ca/flash/i/i_01/i_01_m/i_01_m_ana/i_01_m_ana.html http://jonlieffmd.com/blog/new-type-of-neuroplasticity-involving-changes-in-neurotransmitters http://neuroscience.wikia.com/wiki/Neuron https://en.wikipedia.org/wiki/Neurotransmitter
which neuron secretes neurotransmitters in light