Toward Assessing the Functional Connectivity of Spinal Neurons

Spinal interneurons play a critical role in motor output. A given interneuron may receive convergent input from several different sensory modalities and descending centers and relay this information to just as many targets. Therefore, there is a critical need to quantify populations of spinal interneurons simultaneously. Here, we quantify the functional connectivity of spinal neurons through the concurrent recording of populations of lumbar interneurons and hindlimb motor units in the in vivo cat model during activation of either the ipsilateral sural nerve or contralateral tibial nerve. Two microelectrode arrays were placed into lamina VII, one at L3 and a second at L6/7, while an electrode array was placed on the surface of the exposed muscle. Stimulation of tibial and sural nerves elicited similar changes in the discharge rate of both interneurons and motor units. However, these same neurons showed highly significant differences in prevalence and magnitude of correlated activity underlying these two forms of afferent drive. Activation of the ipsilateral sural nerve resulted in highly correlated activity, particularly at the caudal array. In contrast, the contralateral tibial nerve resulted in less, but more widespread correlated activity at both arrays. These data suggest that the ipsilateral sural nerve has dense projections onto caudal lumbar spinal neurons, while contralateral tibial nerve has a sparse pattern of projections

Il Gastropanel: un test di diagnostica gastrica prezioso e poco conosciuto in medicina generale

Nella diagnostica della patologia gastroesofagea in Medicina Generale, la sintomatologia gioca un ruolo limitato, se si esclude quello legato alla Malattia da Reflusso Gastroesofageo (MRGE) dove la pirosi retrosternale e i rigurgiti acidi sono sufficientemente sensibili per confermare questa affezione, anche con l’utilizzo del PPI test. Nel paziente dispeptico è invece molto difficile identificare la patologia sottostante solo in base ai sintomi e, pur essendo l’incidenza del carcinoma gastrico in netta diminuzione, la preoccupazione di misdiagnosticare questa affezione o le sue condizioni precancerose spinge molti MMG a richiedere una esofagogastroduodenoscopia (EGDS), esame molto utile ma invasivo e non gradito al paziente