Circuit dissection of the role of somatostatin in itch and pain

Stimuli that elicit itch are detected by sensory neurons that innervate the skin. This information is processed by the spinal cord; however, the way in which this occurs is still poorly understood. Here we investigated the neuronal pathways for itch neurotransmission, particularly the contribution of the neuropeptide somatostatin. We find that in the periphery, somatostatin is exclusively expressed in Nppb+ neurons, and we demonstrate that Nppb+somatostatin+ cells function as pruriceptors. Employing chemogenetics, pharmacology and cell-specific ablation methods, we demonstrate that somatostatin potentiates itch by inhibiting inhibitory dynorphin neurons, which results in disinhibition of GRPR+ neurons. Furthermore, elimination of somatostatin from primary afferents and/or from spinal interneurons demonstrates differential involvement of the peptide released from these sources in itch and pain. Our results define the neural circuit underlying somatostatin-induced itch and characterize a contrasting antinociceptive role for the peptide

Mensuração e avaliação da dor pós-operatória: uma breve revisão Medición y evaliación del dolor postquirúrgico: una breve revisión Postoperative pain measurement and assessment: a brief review

Mensurar a dor tem sido grande desafio para aqueles que almejam controlar adequadamente tão complexa experiência. Instrumentos padronizados, que consideram o relato subjetivo do próprio paciente, têm sido elaborados, buscando facilitar tal tarefa. Nesse artigo revisamos os instrumentos mais utilizados para a mensuração da dor pós-operatória, apontando para algumas de suas vantagens e desvantagens. Enfatizamos a necessidade de pesquisas específicas que enfoquem a mensuração da dor no meio cirúrgico, considerando a multidimensionalidade da experiência dolorosa.<br>Mensurar el dolor ha sido gran desafío para aquellos que desean controlar adecuadamente tan compleja experiencia. Instrumentos estandenizados, que consideran el relato subjetivo del própio paciente han sido elaborados buscando facilitar tal tarea. En ese artículo revisamos los instrumentos más utilizados para la mensuración del dolor postquirúrgico, apuntando hacia algumas de sus ventajas y desvantajas. Enfatizamos la necesidad de investigaciones específicas que focalicen la mensuración del dolor en el medio quirúrgico, considerando la multidimensionalidad de la experiencia dolorosa.<br>How to measure pain is a great challenge to those who desire to control adequately such a complex experience. Standardized instruments that take into consideration the patient's own account, have been developed in order to make such a task easier. In this article we carry out a revision of the instruments used mostly for measuring postoperative pain, and we point out some of the advantages and disadvantages. We emphasize the need for specific research focusing on the measurement of surgical pain, taking into consideration the multiple dimensions of a painful experience