Prion protein potentiates acetylcholine release at the neuromuscular junction.

[lansbergen]

http://www.ncbi.nlm.nih.gov/pubmed/16256362

Pharmacol Res. 2006 Jan;53(1):62-8. Epub 2005 Oct 25.

Prion protein potentiates acetylcholine release at the neuromuscular junction.

Re L, Rossini F, Re F, Bordicchia M, Mercanti A, Fernandez OS, Barocci S.

Laboratory of Pharmacological Biotechnology, School of Biological Sciences, University of Ancona, Italy. lambertore@univpm.it

Abstract

Cellular prion protein (PrP(c)), the normal isoform of the pathogenic peptide (PrP(sc)) responsible of the transmissible spongiform encephalopaties (TSEs), is present in many neural tissues, including neuromuscular junctions (NMJ). To analyze if this protein could influence the synaptic transmission, we performed an electrophysiological approach to study the effect of cellular prion protein on a mammalian neuromuscular junction. The loose patch clamp (LPC) technique enables the study of the whole preparation including the pre- and the post-synaptic domains. In a mouse phrenic-diaphragm preparation, nanomolar concentrations of cellular prion protein were able to induce a very striking potentiation of the acetylcholine (ACh) release. The effect was mainly pre-synaptic with an increase of the amplitude of the miniature end-plate currents, probably calcium dependent. Moreover, an apparent facilitation of the synaptic transmission was noted. The results clearly indicate that cellular prion protein may play a key role in the function of the neuromuscular junction.

 

[lansbergen]

http://www.wisegeek.com/what-is-the-phrenic-nerve.htm

The phrenic nerve is one of a pair of nerves, designated left and right, that sends signals between the brain to the diaphragm. When the diaphragm moves, it pulls air into and pushes it out of the lungs. The nerves receive automatic signals to keep the body breathing, but people can also exert some control over the movement of the diaphragm, allowing them to do things like hold their breath. Damage to the nerves impairs that ability and can sometimes cause very serious medical problems.

The Diaphragm

The diaphragm is a large, dome-shaped muscle beneath the lungs that receives its operating signals via the phrenic nerve. When a person inhales, it contracts to give the lungs more room to fill with oxygen-rich air. When a person exhales, it relaxes and pushes up against the lungs, helping expel waste gases like carbon dioxide. It also exerts pressure on the abdominal cavity to help with other bodily functions, like throwing up or urinating. It is one of the few muscles that can operate both involuntarily and under human control. During sleep, the brain sends regular instructions for the diaphragm to contract and relax, but the brain can override these instructions if a person needs to hold a breath.