Recently, total fibrosis has been described to be more abundant in ScAT versus OmAT in humans. Taken into account the pivotal role of TGFb1 in fibrosis and since TGFb1 expression in ATM was higher in obese than non-obese on one hand and in the other in ScAT versus OmAT, we hypothesize a role of ATM in the genesis of ScAT fibrosis. To understand how the neural networks implicated in locomotion might work, it is of great importance to identify their constituents and also to determine their spatial organization. In neonatal rat, numerous studies have characterized putative Tripdiolide Sertraline hydrochloride neurons involved in rhythmic locomotor behaviour. Intracellular recordings have been used to study the cellular properties of unidentified spinal interneuron populations and identified interneurons, such as commissural interneurons involved in left/right coordination. More recently, molecular biological techniques have permitted a systematic classification of diverse ventral spinal cord interneuronal cell types hypothesized to be constituents of the mammalian locomotor CPG such as Ephrine-4 positive interneurons, Hb9 positive interneurons and neurons types designed neurons. Although these studies have provided a wealth of detail about the anatomical location, axonal projections and biophysical properties of constituents of these diverse cell types, they have not elucidated the global anatomical distribution of these functional subgroups. In this study, we investigated the general anatomical organization of flexor and extensor interneuronal circuits within the lumbar SC. This model has provided a fruitful basis for approaching the problem of locomotor generation in limbed vertebrates and has served as the basis for more complex models. Consistent with these different half-center models, one study showed that networks driving flexor and extensor motoneuron pools are functionally and anatomically separated. In the mudpuppy forelimb, the elbow flexor center was localized in the C2 segment, while the elbow extensor center was localized in the C3 and C4 segment. Furthermore, it was shown that the two interneuron pools could oscillate independently. In another study, commissural interneurons located in the ventral horn of L2�CL3 segments and involved in left�Cright coordination have been shown to be anatomically and physiologically separated. Neurons in-phase with the ipsilateral L2 activity are located more ventrally than the out of phase ones. Therefore, the aim of the present study was to determine whether mammalian flexor and extensor cells exhibit a rostro-caudal functional parecellation. To address this question, we performed Ca2+ imaging and lesion experiments using a spinal cord preparation sectioned horizontally just above the central canal. Neurons activated during 5-HT/NMDA-induced fictive locomotion were recorded optically using the Ca2+ indicator fluo-4 AM and the spatiotemporal activation pattern of neurons was analyzed in relation to fictive locomotion recorded from ventral roots. Electrolytic micro-lesions localized between T12 to L2 were also performed in order to detect possible selective disruption of either flexor or extensor motor output. Only one recent study examined the activity of networks of heterogeneous interneurons in the SC. Therefore, this study did not provide a general mapping view of the overall SC.