In the central nervous system brain-derived neurotrophic factor (BDNF) and nerve growth (NGF) are predominantly located in neurons. Here we demonstrate that balance between activity of glutamatergic gamma-aminobutyric acid (GABA)ergic systems controls physiological levels BDNF NGF mRNAs hippocampal neurons vitro vivo. The blockade glutamate receptors and/or stimulation GABAergic reduces hippocampus protein septum. reduction septum reflects diminished availability projection field...

Glycine is the major inhibitory neurotransmitter in spinal cord and brainstem also required for activation of NMDA receptors. The extracellular concentration this neuroactive amino acid regulated by at least two glycine transporters (GLYT1 GLYT2). To study localization properties these proteins, sequence-specific antibodies against cloned have been raised. Immunoblots show that 50-70 kDa band corresponding to GLYT1 expressed highest concentrations cord, brainstem, diencephalon, retina, and,...

Specific sensory input has profound transient and long-lasting effects on the function of corresponding cortical areas both during development in adulthood. To study whether neurotrophic factors might play a role such processes, we investigated light nerve growth factor brain-derived (BDNF) mRNA levels rat visual cortex. Keeping adult rats dark or preventing normal activity retinal ganglion cells by intraocular injection tetrodotoxin significantly decreased BDNF cortex but not other areas....

Transforming growth factor-beta 1 (TGF-beta 1) has been shown to up-regulate the synthesis of nerve factor (NGF) in cultured rat astrocytes and neonatal brain vivo (Lindholm, D., B. Hengerer, F. Zafra, H. Thoenen. 1990. NeuroReport. 1:9-12). Here we show that mRNA encoding TGF-beta increased cerebral cortex after a penetrating injury. The level NGF is also transiently trauma, whereas brain-derived neurotrophic remained unchanged. In situ hybridization experiments showed strong expression 4 d...

Brain-derived neurotrophic factor (BDNF) and NGF are both expressed by neurons in the hippocampus. In previous studies, it has been demonstrated that BDNF mRNA levels regulated neuronal activity. Upregulation is predominantly glutamate (NMDA non-NMDA receptors); downregulation, GABA system (Zafra et al., 1990, 1991). cultures of rat hippocampus, potassium depolarization kainic acid-mediated increases were eliminated a dose-dependent manner calcium channel blocker nifedipine. Conversely,...

High affinity sodium- and potassium-coupled L-glutamate transport into presynaptic nerve terminals fine glial processes removes the neurotransmitter from synaptic cleft, thereby terminating glutamergic transmission. This report describes that purified transporter pig brain is phosphorylated by protein kinase C, predominantly at serine residues. Upon exposure of C6 cells, a cell line origin, to 12-O-tetradecanoylphorbol-13-acetate, about 2-fold stimulation observed within 30 min....

The high-affinity glycine transporter in neurons and glial cells is the primary means of inactivating synaptic glycine. Previous molecular cloning studies have indicated heterogeneity transporters CNS. Here distribution GLYT1 GLYT2 transcripts proteins different regions developmental stages rat brain were analysed by Northern, Western situ hybridization techniques. Sequence-specific riboprobes two specific antibodies raised against fusion used, containing either 76 or 193 amino acids C N...

gamma-Aminobutyric acid (GABA) is the major inhibitory neurotransmitter in adult mammalian central nervous system. However, GABA depolarizes immature rat hippocampal neurons and increases intracellular Ca2+ ([Ca2+]i). Here we show, that GABAA receptor agonist muscimol induce c-Fos immunoreactivity increase BDNF mRNA expression embryonic cultured for 5 days. In contrast, after 3 weeks culture, failed to c-fos expression. Fura-2 fluorescence microscopy revealed produces a...

In previous experiments it has been demonstrated that the synthesis of BDNF (brain-derived neurotrophic factor) and NGF in neurons hippocampus is regulated by neuronal activity. The glutamate system predominantly responsible for upregulation GABAergic downregulation both vitro vivo (Zafra et al., 1990, 1991). aim present study to examine extent which cholinergic also involved regulation mRNA whether regulatory contribution changes during development. Partial transection fimbria fornix bundle...

TRANSFORMING growth factor-β1 (TGF-β1) markedly increased the, mRNA encoding nerve factor (NGF) in cultured rat astrocytes a time- and concentration-dependent manner. The maximal effect of TGF-β1 (a 50-fold increase NGF-mRNA) was reached after 24 h incubation. TGF-β-mediated NGF-mRNA results from enhanced transcription as shown nuclear run-on studies transfection assays using the NGF promoter linked to chloramphenicol acetyltransferase (CAT) reporter gene. also its own expression well that...

The effect of unilateral excitotoxic ablation hippocampal neurons was investigated on (1) the local production mRNA for NGF and related neurotrophins, (2) amount protein in septal region, (3) viability appearance afferent cholinergic adult rats. After near complete neurons, total levels NGF, brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT3) measured by quantitative Northern blot analysis remnant fell significantly, to less than 25% control values 28 d 9% 300 d. In region...

Glutamate transporter-1 (GLT-1) is the main glutamate transporter in central nervous system, and its concentration severely decreases neurodegenerative diseases. The number of transporters plasma membrane reflects balance between their insertion removal, it has been reported that regulated endocytosis GLT-1 depends on ubiquitination triggered by protein kinase C (PKC) activation. Here, we identified serine 520 as primary target for PKC-dependent phosphorylation, although elimination this did...

Abstract The effects of 12‐ O ‐tetradecanoylphorbol 13‐acetate (TPA), a potent activator protein kinase C, on high‐affinity Na + ‐dependent glutamate transport were investigated in primary cultures neurons and glial cells from rat brain cortex. Incubation with TPA led to concentration‐ time‐dependent increases the that could be completely suppressed by addition C (PKC) inhibitor 1‐(5‐isoquinolinylsulfonyl)‐2‐methylpiperazine. mimicked oleoylacetylglycerol diacylglycerol R59022. potentiated...

Glycine transporter GLYT2 is an axonal glycoprotein involved in the removal of glycine from synaptic cleft. To elucidate role carbohydrate moiety on function, we analyzed effect disruption putativeN-glycosylation sites transport activity, intracellular traffic COS cells, and asymmetrical distribution this protein polarized Madin-Darby canine kidney (MDCK) cells. Transport activity was reduced by 35–40% after enzymatic deglycosylation reconstituted into liposomes. Site-directed mutagenesis...

Abstract Glucocorticoid hormones are important regulators of brain development and ageing. Here we show that dexamethasone, a synthetic glucocorticoid, differentially affects the expression nerve growth factor (NGF) in cultured neurons astrocytes. Dexamethasone increased levels NGF mRNA hippocampal time‐ concentration‐dependent manner, whereas it down‐regulated However, dexamethasone had no effect on brain‐derived neurotrophic neurons. Aldosterone, mineralocorticoid, higher concentrations...

To elucidate the role of N-glycosylation in function high affinity glycine transporter GLYT1, we have investigated effect glycosylation inhibitor tunicamycin as well disruption putative sites by site-directed mutagenesis. SDS-polyacrylamide gel electrophoresis proteins from GLYT1-transfected COS cells reveals a major band 80-100 kDa and minor one 57 kDa. Treatment with produces 40% inhibition transport activity decrease intensity 80-100-kDa band, whereas 57-kDa decreases size to yield 47-kDa...

Abstract The SNAT5 transporter is a neutral amino acid carrier whose function remains unclear. Structural and mechanistically, closely related to the SNAT3 that mediates efflux of glutamine from glial cells participates in glutamate‐glutamine cycle brain. In this study, we have analyzed distribution rat central nervous system using specific antibodies. Through immunoblotting observed ubiquitously but unevenly distributed CNS. It accumulates most intensely neocortex, hippocampus, striatum,...

Abstract The activity of the main glutamate transporter in CNS, GLT1, can be regulated by protein kinase C (PKC). It is known that activation PKC phorbol esters promotes clathrin‐dependent internalization transporter, followed its lysosomal degradation. However, molecular mechanisms link and GLT1 are not fully understood. In this article, we show process dependent on ubiquitylation lysine residues located C‐terminal tail GLT1. Exposure to PMA increases transfected cells rat brain,...

The main glutamate transporter in the brain, GLT-1, mediates glutamatergic neurotransmission both physiological and pathological conditions. GLT-1 activity is controlled by constitutive regulated trafficking, although recent evidence indicates that turnover of this protein plasma membrane accelerated kinase C via an ubiquitin-dependent process, mechanisms driving trafficking remain unexplored. Here, we used a heterologous system primary astrocytes to investigate role ubiquitin attachment...