Blocking Pannexin 1 Channels Alleviates Peripheral Inflammatory Pain but not Paclitaxel-Induced Neuropathy.

Background: Pannexin1 (Panx1) is a membrane channel expressed in different cells of the nervous system and is involved in several pathological conditions, including pain and inflammation. At the central nervous system, the role of Panx1 is already well-established. However, in the periphery, there is a lack of information regarding the participation of Panx1 in neuronal sensitization.

Alloxan as a better option than streptozotocin for studies involving painful diabetic neuropathy.

Previous data indicate that the diabetogenic substance streptozotocin might act in nociceptive neurons changing the sensory signal, regardless of hyperglycemia. In the present article the effects of streptozotocin were compared with another diabetogenic drug, alloxan, for diabetes induction in rats. A possible direct effect of these drugs was tested by means of in vivo experiments and in vitro assays using cultured primary nociceptive neurons.

Peripheral Inflammatory Hyperalgesia Depends on P2X7 Receptors in Satellite Glial Cells.

Peripheral inflammatory hyperalgesia depends on the sensitization of primary nociceptive neurons. Inflammation drives molecular alterations not only locally but also in the dorsal root ganglion (DRG) where interleukin-1 beta (IL-1β) and purinoceptors are upregulated. Activation of the P2X7 purinoceptors by ATP is essential for IL-1β maturation and release.

Altered morphology and function of the peripheral nociceptive system in the offspring of diabetic rats.

The aim of this study was to determine whether maternal diabetes induced by alloxan injection in the first gestational day of female Wistar rats interferes with the development of the nociceptive peripheral system of the offspring. Behavioral and histologic analysis was performed using the adult offspring of diabetic and control rats. It was found that the offspring of diabetic rats were more sensitive to thermal stimulation and showed an altered response to carrageenan-induced inflammatory hyperalgesia.

Hyperglycemia induces mechanical hyperalgesia and depolarization of the resting membrane potential of primary nociceptive neurons: Role of ATP-sensitive potassium channels.

Cumulating data suggests that ion channel alterations in nociceptive neurons might be involved in the development of diabetic painful neuropathy. In the present study we investigated the involvement of ATP-sensitive potassium (K) channels in the acute effect of high glucose solution in vitro and in vivo. High glucose concentrations depolarized cultured nociceptive neurons and depolarization was blocked by the K opener, diazoxide or by insulin.

Participation of satellite glial cells of the dorsal root ganglia in acute nociception.

At dorsal root ganglia, neurons and satellite glial cells (SGC) can communicate through ATP release and P2X7 receptor activation. SGCs are also interconnected by gap junctions and have been previously implicated in modulating inflammatory and chronic pain.We now present evidence that SGCs are also involved in processing acute nociception in rat dorsal root ganglia.

Quantitative Analysis of Rat Dorsal Root Ganglion Neurons Cultured on Microelectrode Arrays Based on Fluorescence Microscopy Image Processing.

Microelectrode Arrays (MEA) are devices for long term electrophysiological recording of extracellular spontaneous or evocated activities on in vitro neuron culture. This work proposes and develops a framework for quantitative and morphological analysis of neuron cultures on MEAs, by processing their corresponding images, acquired by fluorescence microscopy. The neurons are segmented from the fluorescence channel images using a combination of segmentation by thresholding, watershed transform, and object classification.