Brain-derived neurotrophic factor (BDNF) is synthesized by small neuron cell bodies in the dorsal root ganglia (DRG) and anterogradely transported to primary afferent terminals horn where it involved modulation of painful stimuli. Here we show that BDNF released rat isolated after chemical stimulation capsaicin or electrical roots. Capsaicin superfusion (1–100 μ m ) induced a dose-dependent release BDNF, measured using ELISA. The highest dose also depletion protein horn. was seen roots at...

Abstract NMDA receptors in primary afferent terminals can contribute to hyperalgesia by increasing neurotransmitter release. In rats and mice, we found that the ability of intrathecal induce neurokinin 1 receptor ( NK 1R) internalization (a measure substance P release) required a previous injection BDNF . Selective knock‐down afferents decreased ‐induced 1R internalization, confirming presynaptic location these receptors. The effect was mediated tropomyosin‐related kinase B (trkB) not p75...

The excitability of spinal neurons that transmit pain is modulated by glutamate and substance P (SP). Glutamate an excitatory neurotransmitter in the dorsal horn, its effects are enhanced SP acting on neurokinin 1 receptors (NK1Rs). We assessed activation NK1Rs studying their internalization cord slices. were localized sections from slices using immunohistochemistry combined with fluorescence confocal microscopy. Incubating induced most NK1R-positive laminae I, IIo, X half III-V. SP-induced...

N-methyl-D-aspartate (NMDA) receptors in sensory afferents participate chronic pain by mediating peripheral and central sensitization. We studied the presence of NMDA receptor subunits different types primary afferents. Western blots indicated that rat dorsal root ganglia (DRG) contain NR1, NR2B, NR2C, NR2D but not NR2A. Real-time RT-PCR showed NR2B were expressed at higher levels than NR2A NR2C DRG. Immunofluorescence with an antibody recognized NR1 another colocalized 90% DRG neurons,...

Abstract: 1‐Aminocyclopropane carboxylic acid (ACPC) competitively inhibited (IC 50 , 38 ± 7 n M ) [ 3 H]glycine binding to rat forebrain membranes but did not affect H]strychnine brainstem/ spinal cord membranes. Like glycine, ACPC enhanced H‐labelled (+)‐5‐methyl‐10,11 ‐dihydro‐5 H ‐dibenzo[ a, d ]cyclohepten‐5,10‐imine maleate ([ H]MK‐801) TV‐methyl‐D‐aspartate receptor‐coupled cation channels (EC 135 76 and 206 78 for respectively) was ∼ 40% less efficacious in this regard. The maximum...

Opioid μ- and δ-receptors are present on the central terminals of primary afferents, where they thought to inhibit neurotransmitter release. This mechanism may mediate analgesia produced by spinal opiates; however, when used neurokinin 1 receptor (NK1R) internalization as an indicator substance P release, Trafton et al. (1999) noted that this evoked was altered only modestly morphine delivered intrathecally at cord segment S1-S2. We reexamined issue studying effect opiates NK1R in slices...

Calcitonin receptor-like receptor (CLR) and activity modifying protein 1 (RAMP1) comprise a for calcitonin gene related peptide (CGRP) intermedin. Although CGRP is widely expressed in the nervous system, less known about localization of CLR RAMP1. To localize these proteins, we raised antibodies to Antibodies specifically interacted with RAMP1 HEK cells coexpressing rat RAMP1, determined by Western blotting immunofluorescence. Fluorescent bound surface CGRP, CLR, internalized into same...

The role of ras proteins in signal transduction was assessed by studying inositol phospholipid metabolism and phospholipid-mediated cellular responsiveness to agonists cells transformed other oncogenes. Specific alterations were observed the cycle ras-transformed fibroblasts, but similar changes also produced spontaneous transformation or mediated either membrane-associated oncogenes, such as src, met, trk, cytoplasmic mos raf; nuclear oncogenes fos myc did not produce these changes....

Many chronic pain disorders alternate between bouts of and periods remission. The latent sensitization model reproduces this in rodents by showing that the apparent recovery (“remission”) from inflammatory or neuropathic can be reversed opioid antagonists. Therefore, remission represents an receptor-mediated suppression a sustained hyperalgesic state. To identify receptors involved, we induced mice rats injecting complete Freund's adjuvant (CFA) hindpaw. In WT mice, responses to mechanical...

The displacement by glycine of 3H-strychnine binding to rat spinal cord membranes cannot be explained a simple competitive interaction. Indeed, protein-modifying reagents can completely abolish the inhibition and other agonists, whereas interaction strychnine itself related compounds with site is unimpaired. Moreover, inhibit saturable binding, extent its maximum inhibitory effect depending on ionic composition medium. Hill coefficients less than 1 (whose magnitude also depends assay medium)...

To characterize neuronal pathways that release opioid peptides in the rat dorsal horn, multiple-label immunohistochemistry, confocal microscopy, and computerized co-localization measures were used to opioid-containing terminals cells. An antibody selectively recognized beta-endorphin labeled fibers neurons ventral horn as well lateral funiculus lamina X, but practically no horn. anti-enkephalin antibody, which Leu-, Met-, Phe-Arg-Met-enkephalin, dorsolateral numerous puncta laminae I-III V...

Abstract Latent sensitization is a rodent model of chronic pain that reproduces both its episodic nature and sensitivity to stress. It triggered by wide variety injuries ranging from injection inflammatory agents nerve damage. follows characteristic time course in which hyperalgesic phase followed remission. The lasts between few days several months, depending on the triggering injury. Injection μ‐opioid receptor inverse agonists (e.g., naloxone or naltrexone) during remission induces...

Abstract Inhibitory amino acids have antinociceptive actions in the spinal cord that may involve inhibition of neurotransmitter release from primary afferents. Rat slices with dorsal roots were used to study effect GABA and glycine on substance P release, assessed by internalization neurokinin 1 receptors. After electrical stimulation root at 100 Hz, about half receptor‐immunoreactive neurons laminae I–II o showed internalization. This was inhibited (100 μ m ) B agonist R‐baclofen (10 ), but...

To evaluate the effect of peptidases on mu-opioid receptor (MOR) activation by endogenous opioids, we measured MOR-1 internalization in rat spinal cord slices. A mixture inhibitors aminopeptidases (amastatin), dipeptidyl carboxypeptidase (captopril), and neutral endopeptidase (phosphoramidon) dramatically increased potencies Leu-enkephalin dynorphin to produce internalization, also enhanced effects Met-enkephalin alpha-neoendorphin, but not endomorphins or beta-endorphin. The omission any...

To determine what neural pathways trigger opioid release in the dorsal horn, we stimulated root, or dorsolateral funiculus (DLF) spinal cord slices while superfusing them with peptidase inhibitors to prevent degradation. Internalization of mu-opioid receptors (MOR) and neurokinin 1 (NK1R) was measured assess release, respectively. Dorsal root stimulation at low, high, mixed frequencies produced abundant NK1R internalization but no MOR internalization, indicating that primary afferents do not...

Abstract: The thermodynamic parameters associated with the interactions of agonists and antagonists glycine receptors in rat spinal cord membranes were determined. binding antagonist [ 3 H]strychnine inhibition strychnine by 11 different glycinergic ligands examined at temperatures between 0.5 37°C density was not affected temperature which incubation performed, but ability receptor to compete varied markedly. affinity for strychnine, 2‐aminostrychnine, RU‐5135,5,6,7,8‐tetrahydro‐4 H...