Glycinergic neurons

Zeilhofer, H. U., Studler, B Arabadzisz, D. et al. (2005). Glycinergic neurons expressing enhanced green fluorescent protein in bacterial artificial chromosome transgenic mice. J. Comp. Neurol. 482, 123-41. 

GABA (y-aminobutyric acid) is derived from glutamate by decarboxylation. It occurs predominantly in inhibitory synapses in the central nervous system, as does glycine. Tetanus toxin acts on glycinergic neurons in the spinal cord, which exert inhibitory regulation on the a-motoneurons. ... 

Maximal release of acetylcholine by the motoneurons occurs in tetanus, due to the toxin-mediated inactivation of glycinergic neurons that normally inhibit them. This results not in blockade but maximal muscle activity, so strong that bone fractures are commonly observed. However, blockade can be observed with inhibitors of acetylcholine esterase (see below). 

The amino acid glycine binds to pentameric glycine receptors (similar structure as nAChR) which are ligand-gated Cl- channels. Inhibitory glycinergic neurons are in the brain stem and spinal cord and regulate involuntary motoric via Renshaw interneurons. 

Yang, K., Fujita, T. 8r Kumamoto, E. (2004). Adenosine inhibits GABAergic and glycinergic transmission in adult rat substantia gelatinosa neurons. /. Neurophysiol. 92 (5), 2867-77. 

Trendelenburg AU, Meyer A, Klebroff W et al (2003) Cross talk between presynaptic angiotensin receptors, bradykinin receptors and a2-autoreceptors in sympathetic neurons a study in a.2-adrenoceptor-deficient mice. Br J Pharmacol 138 1389-1402 Umemiya M, Berger AJ (1994) Activation of adenosine Aj and A2 receptors differentially modulates calcium channels and glycinergic synaptic transmission in rat brainstem. Neuron 13 1439—46... 

Certain other substances (tetanus toxin) reach nerve cells directly via distal axonal entry. Tetanus toxin is transported to the spinal anterior horn cell, subsequently translocates and binds to presynaptic inhibitory (glycinergic) nerve terminals impinging on the motor nerve cell, and thereby suppresses the inhibition of motor neuron activity leading to hyperexcitation. Violent and sustained muscle contraction (tetany) results in response to external stimulation. Another example of peripheral entry to the CNS is the transport and delivery of metals (manganese, aluminum) from the nose along olfactory neurons to the brain of laboratory animals. 

Abstract The CBi cannabinoid receptor is widely distributed in the central and peripheral nervous system. Within the neuron, the CBi receptor is often localised in axon terminals, and its activation leads to inhibition of transmitter release. The consequence is inhibition of neurotransmission via a presynaptic mechanism. Inhibition of glutamatergic, GABAergic, glycinergic, cholinergic, noradrenergic and serotonergic neurotransmission has been observed in many regions... 

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