The Distribution of Glycine, Gaba, Glutamate and Aspartate in Rabbit Spinal Cord, Cerebellum and Hippocampus

Abstract

The distribution of glycine, GABA, glutamate and aspartate was measured among about 60 subdivisions of rabbit spinal cord, and among the discrete layers of cerebellum, hippocampus and area dentata. A more detailed mapping for GABA was made within the tip of the dorsal horn of the spinal cord. Spinal ventral horn and dorsal root ganglion cell bodies were analyzed for the amino acids and for total lipid. The distribution of lipid and lipid-free dry weight per unit volume was also determined in spinal cord. Calculated on the basis of tissue water, glycine in the cord is highest in lateral and ventral white matter immediately adjacent to the ventral grey. The distribution of GABA is almost the inverse of that of glycine with highest level in the tip of dorsal horn. It is most highly concentrated in the central 75% of Rexed layers I11 and IV. Aspartate in the tip of ventral horn is 4-fold higher than in the tip of the dorsal horn and 3 times the average concentration in brain. Glutamate was much more evenly distributed and is relatively low in concentration with slightly higher levels in dorsal than in ventral grey matter. Large cell bodies in both ventral horn and dorsal root ganglion contained high levels of glycine. As reported by others, GABA was found to be high in cerebellar grey layers, area dentata, and regio inferior of hippocampus. Glycine was moderately high in cerebellar layers but moderate to low in hippocampus and area dentata.

Glutamate Binding to the GluN2B Subunit Controls Surface Trafficking of N-Methyl-d-aspartate (NMDA) Receptors*

“…Although accurate estimates of glutamate concentration in the ER lumen are lacking, glutamate is readily detected in the ER, and average intracellular concentrations are thought to be in the millimolar range (e.g. 4 -16 mM in various brain regions (15,37,38)). The finding here that the constitutively closed cleft GluN2B KNCC traffics to the surface like wild type GluN2B and does not exhibit enhanced surface expression (Fig.…”

The Integrity of the Glycine Co-agonist Binding Site of N-Methyl-d-aspartate Receptors Is a Functional Quality Control Checkpoint for Cell Surface Delivery

“…Affinity-purified anti-NR1- (35)(36)(37)(38)(39)(40)(41)(42)(43)(44)(45)(46)(47)(48)(49)(50)(51)(52)(53); anti-NR1 C2-(911-920); anti-NR2A-(44 -58 Cys), and anti-NR2A-(1381-1394) antibodies were raised and characterized as previously reported (30,32,33). Mouse monoclonal antibodies to calreticulin and the 58-kDa Golgi protein were from Abcam (Cambridge, UK).…”

Glycine Uptake Regulates Hippocampal Network Activity via Glycine Receptor-Mediated Tonic Inhibition

“…However, subsequent application of STN had no effect on E-S coupling, implying that glia is also essential for the release of glycine. Glia has been shown to contain B2 mM glycine (Berger et al, 1977), which enables glia to participate in the control of glycine concentration. Furthermore, two-thirds of the axon-dendritic spines in CA1 region are associated with astrocytic processes (Ventura and Harris, 1999), suggesting a wide distribution and close colocalization of glial cells with neurons.…”