Na-K-2Cl symporter contributes to γ-aminobutyric acid-evoked excitation in rat enteric neurons.

Gamma-aminobutyric acid (GABA) is an inhibitory neurotransmitter in the adult central nervous system (CNS), however, it causes excitation in the immature CNS neurons. The shift from GABA-induced depolarization to hyperpolarization in postnatal brain is primarily due to progressive decrease in the expression of the Na-K-2Cl symporter 1 (NKCC1) and increased expression of the K-Cl cotransporter 2 (KCC2). Unlike CNS neurons, both immature and mature neurons in the enteric nervous system (ENS) are depolarized by GABA.

Cellular mechanisms that determine selective RGS protein regulation of G protein-coupled receptor signaling.

Regulators of G protein signaling (RGS proteins) bind directly to activated Galpha subunits to inhibit their signaling. However, recent findings show that RGS proteins selectively regulate signaling by certain G protein-coupled receptors (GPCRs) in cells, irrespective of the coupled G protein. New studies support an emerging model that suggests RGS proteins utilize both direct and indirect mechanisms to form stable functional pairs with preferred GPCRs to selectively modulate the signaling functions of those receptors and linked G proteins.

Concentrated hydriodic acid in simultaneous deprotections of multifunctional inositols.

l-1-Deoxy-1-fluoro-6-O-methyl-myo-inositol was epimerized by chloral/DCC in boiling 1,2-dichloroethane yielding D-1-O-cyclohexylcarbamoyl-2-deoxy-2-fluoro-3-O-methyl-5,6-O-[(R/S)-2,2,2-trichloroethylidene]-chiro-inositol. The latter and l-4-O-benzyl-3-O-cyclohexylcarbamoyl-5-O-methyl-1,2-O-(2,2,2-trichloroethylidene)-muco-inositol, l-4-O-benzyl-3-O-cyclohexylcarbamoyl-1,2-O-ethylidene-5-O-methyl-muco-inositol, d-1-O-cyclohexylcarbamoyl-2-deoxy-5,6-O-ethylidene-2-fluoro-3-O-methyl-chiro-inositol, as well as D-5-O-benzyl-4-O-cyclohexylcarbamoyl-3-deoxy-3-(N,N'-dicyclohexylureido)-6-O-methyl-1,2-O-(2,2,2-trichloroethylidene)-chiro-inositol were deprotected with boiling 57% aq hydrogen iodide. Ether, urethane and ethylidene acetal functions were simultaneously cleaved by the reagent, whereas the trichloroethylidene groups were still intact or were only removed in small quantities.

Penetrating brain injury leads to activation of ciliary neurotrophic factor receptors.

Endogenous injury response mechanisms likely reduce secondary neuronal loss following CNS trauma by activating growth factor receptors. Therefore, it is important to determine which growth factor receptors are activated in vivo by CNS trauma and which signal transduction pathways are affected in which cell types. We present a model of penetrating brain injury utilizing stereotaxic insertion of a fine needle.

STAT3 phosphorylation in injured axons before sensory and motor neuron nuclei: potential role for STAT3 as a retrograde signaling transcription factor.

STAT3 is a latent transcription factor that is activated by plasma membrane growth factor receptor complexes. Conditional gene disruption data indicate that it contributes to the survival of cranial motor neurons after peripheral nerve lesion. In agreement, levels of activated STAT3 (Tyr705-phosphorylated STAT3) have been shown to increase in the nuclei of adult cranial motor neurons during their regeneration after the same injury.

In vivo localization and characterization of functional ciliary neurotrophic factor receptors which utilize JAK-STAT signaling.

The ciliary neurotrophic factor receptor is critically involved in embryonic motor neuron development. Postnatally, it may contribute to neuronal maintenance and regeneration. In addition, pharmacological stimulation of the receptor may slow the progression of several neurodegenerative disorders.

Antisense studies in PC12 cells suggest a role for H218, a sphingosine 1-phosphate receptor, in growth-factor-induced cell-cell interaction and neurite outgrowth.

Our previous studies of H218, a sphingosine 1-phosphate (S1P) receptor and a member of the G-protein-coupled receptor superfamily, suggest that it may participate in mammalian nervous system development. Thus, brain levels of H218 mRNA are higher during early neurogenesis than postnatally. In addition, embryonic H218 immunoreactivity is preferentially localized in young neuronal cell bodies during their early stages of differentiation and in axons during their extension.

Regulation of ciliary neurotrophic factor receptor alpha in sciatic motor neurons following axotomy.

Spinal motor neurons are one of the few classes of neurons capable of regenerating axons following axotomy. Injury-induced expression of neurotrophic factors and corresponding receptors may play an important role in this rare ability. A wide variety of indirect data suggests that ciliary neurotrophic factor receptor alpha may critically contribute to the regeneration of injured spinal motor neurons.

Electrodermal responses to sensory stimuli in individuals with fragile X syndrome: a preliminary report.

The fragile X mutation and fragile X syndrome are associated with hyperarousal, hyperactivity, aggression, and anxiety. These may be related to strong reactions to auditory, tactile, visual, and olfactory stimuli [Hagerman, 1996b; Hagerman and Cronister, 1996]. However, almost no data exist describing hyperarousal and sensory sensitivity in individuals with the fragile X mutation.

Expanding the role of the genetic counselor.

The basic components of genetic counseling are informational and educational. The patient's cognitive and emotional presentation and the needs and concerns of the patient are seldom addressed. Females who carry the FMR1 pre and full gene mutation may present with learning, cognitive, and/or emotional difficulties and family members of those diagnosed with fragile X syndrome have ongoing needs and concerns.