Formulation of evidence-based messages to promote the use of physical activity to prevent and manage Alzheimer's disease.

Background: The impending public health impact of Alzheimer's disease is tremendous. Physical activity is a promising intervention for preventing and managing Alzheimer's disease. However, there is a lack of evidence-based public health messaging to support this position.

Modulation of glutamate release from parallel fibers by mGlu4 and pre-synaptic GABA(A) receptors.

The regulation of pre-synaptic glutamate release is important in the maintenance and fidelity of excitatory transmission in the nervous system. In this study, we report a novel interaction between a ligand-gated ion channel and a G-protein coupled receptor which regulates glutamate release from parallel fiber axon terminals. Immunocytochemical analysis revealed that GABA(A) receptors and the high affinity group III metabotropic glutamate receptor subtype 4 (mGlu4) are co-localized on glutamatergic parallel fiber axon terminals in the cerebellum.

Calcium-sensing receptor modulates cell adhesion and migration via integrins.

The calcium-sensing receptor (CaSR) is a family C G protein-coupled receptor that is activated by elevated levels of extracellular divalent cations. The CaSR couples to members of the G(q) family of G proteins, and in the endocrine system this receptor is instrumental in regulating the release of parathyroid hormone from the parathyroid gland and calcitonin from thyroid cells. Here, we demonstrate that in medullary thyroid carcinoma cells, the CaSR promotes cellular adhesion and migration via coupling to members of the integrin family of extracellular matrix-binding proteins.

Motor learning in the VOR: the cerebellar component.

This paper reviews results that support a model in which memory for VOR gain is initially encoded in the flocculus, and in which cerebellar LTD and LTP are responsible for gain increases and gain decreases, respectively. We also review data suggesting that after it is encoded, motor memory can either be disrupted, possibly by a local mechanism, or else consolidated. We show that consolidation can be rapid, in which case the frequency dependence of learning is unchanged and we will argue that this is consistent with a local mechanism of consolidation.

Determination of L-serine-O-phosphate in rat and mouse brain tissue using high-performance liquid chromatography and fluorimetric detection.

L-Serine-O-phosphate (L-SOP), the precursor of l-serine, is an agonist at group III metabotropic glutamate receptors. Despite the interest in L-SOP, very few articles have reported its brain levels. Here we report a convenient and reproducible method for simultaneous analysis of L-SOP and several other important amino acids in brain tissue using high-performance liquid chromatography (HPLC) with fluorimetric detection after derivatization with o-phthaldialdehyde and N-isobutyl-L-cysteine.

The effects of a low protein diet on amino acids and enzymes in the serine synthesis pathway in mice.

L-serine is required for cellular and tissue growth and is particularly important in the immature brain where it acts as a crucial neurotrophic factor. In this study, the levels of amino acids and enzymes in the L-serine biosynthetic pathway were examined in the forebrain, cerebellum, liver, and kidney after the exposure of mice to protein-restricted diets. The levels of L-serine, D-serine, and L-serine-O-phosphate were quantified by HPLC and quantitative Western blotting was used to measure changes in protein levels of five enzymes in the pathway.

L-Serine-O-phosphate in the central nervous system.

L-serine-O-phosphate (L-SOP) is the immediate precursor to L-serine in the serine synthesis pathway and is also an agonist at the Group III metabotropic glutamate receptors (mGluRs). L-SOP is produced by the enzyme phosphoserine aminotransferase (PSAT) and metabolized to L-serine by phosphoserine phosphatase (PSP). Using a novel analytical procedure, we show that L-SOP is present in rat whole brain, and that in transfected cells, it is substantially more potent than L-glutamate at the mGluR4 receptor subtype.

Glutamate transporter coupling to Na,K-ATPase.

Deactivation of glutamatergic signaling in the brain is mediated by glutamate uptake into glia and neurons by glutamate transporters. Glutamate transporters are sodium-dependent proteins that putatively rely indirectly on Na,K-ATPases to generate ion gradients that drive transmitter uptake. Based on anatomical colocalization, mutual sodium dependency, and the inhibitory effects of the Na,K-ATPase inhibitor ouabain on glutamate transporter activity, we postulated that glutamate transporters are directly coupled to Na,K-ATPase and that Na,K-ATPase is an essential modulator of glutamate uptake.