Help with Neurotransmitter and Receptor Physiology

Muscarinic acetylcholine receptors (mAChRs) are found in the G protein-receptor complexes in the cell membrane of certain neurons. The suffix -ergic means exhibiting or stimulating the activity of. For example, dopaminergic receptors bind to dopamine.

Norepinephrine is released by adrenergic neurons.

Cholinergic neurons release acetylcholine as their neurotransmitter (in the sympathetic or parasympathetic nervous system).

Nonadrenergic, noncholinergic neurons (which include postganglionic parasympathetic neurons of the gastrointestinal tract) release substance P and nitric oxide.

Acetylcholine is the neurotransmitter found at the neuromuscular junction and many other synapses found in the nervous system. It binds to receptors on the postsynaptic membrane to induce muscular contraction.

GABA is the most common inhibitory neurotransmitter in the brain. Glutamate is the most common excitatory neurotransmitter in the brain. Dopamine is a monoamine which can sometimes be inhibitory, but is not the most common.

Glutamic acid is an excitatory neurotransmitter. During a cerebrovascular accident, cells that have died due to oxygen deprivation release large quantities of glutamic acid. This causes surrounding cells to become overexcited and eventually die. This process is called excitotoxicity.

Neurotransmitters are packaged in vesicles, traveling through the synaptic cleft (space between neurons) from the pre-synaptic membrane to the post-synaptic membrane, where they bind to their receptors and influence the post-synaptic membrane potential.

The substantia nigra is composed of primarily dopamine. When the substantia nigra is effected by a disease, a patient can present with Parkinson-like symptoms. Most common symptom is resting tremors.

Acetylcholine activates muscarinic receptors in postganglioinic parasympathetic nervous tissue and nicotinic receptors in skeletal muscle fibers, and preganglionic sympathetic and parasympathetic nervous tissue.

Nociceptors are pain receptors that. Mechanoreceptors respond when tissue is deformed by mechanical forces. Photoreceptors respond to light. Chemoreceptors respond to chemicals. Thermoreceptors respond to changes in temperature.

Pacinian corpuscles are found in deeper in the dermis rather than in the dermal papillae. Merkel cells are found in the epidermal-dermal border and are responsible for perception of light and touch. Carcinoma is a type of tumor. Meissner's corpuscles are the mechanoreceptors that are found in the dermal papillae, and are very sensitive to light touches.