Ionotropic & Metabotropic receptors and PNS Neurotransmitters

what binds to Ionotropic receptors

GABA, Glutamate, Acetylcholine, and serotonin

G-proteins

Apart of the metabotropic receptors it is from the intercellular side of the receptor that releases a subunit ( the Alpha subunit) which usually effects ion channels.

What NTs binds to metabotropic receptors

Small-molecules, Lipids, Peptide NTs

What are the two ways a metabotropic receptor will active an channel.

Once the binding NT trigger the activation of the G-protein the alpha subunit with either:

1. Bind to a channel causing it to open allowing ions to pass through.

2. Binds to an enzyme which activates a second messenger. this messenger will then active another cell process:
   a) forming new ion channel

   b) Activates DNA in order to produce a new protein

PNS Somatic Nervous system

Motor neurons use Acetylcholine ( also know as the nicotine receptors) which will bind to muscle fibers opening an channel allowing a efflux of K & influx of Na. This will depolarize the membrane and and initiates AP (causes muscle fibers to contract)

PNS: Autonomic Nervous System

Consist of the cranial nerves & some spinal nerves and it handles the resting phase of the body. these nerves have two parts tot hem and depending on the the type of system the part vary:

• parasympathetic: acetylcholine

• sympathetic: acetylcholine ( 1st) AND norepinephrine ( 2nd)