RESUMEN
The present study yields informations on the location, number and size of motor, sensory and postganglionic sympathetic neurons forming the femoral nerve in albino rats localized by horseradish peroxidase [HRP] method of tracing neuronal connections. It showed that the motoneurons of femoral nerve extended between L[1] and L[4] segments of the spinal cord. They appeared as groups of neurons occupying anterolateral, posterolateral and central groups. The labeled sensory neurons were located in L[1] - L[4] dorsal root ganglia[DRG] and were concentrated mostly in L[3] DRG with no somatotopic organization of the cells. The postganglionic sympathetic neurons [PSN] were labeled in L[1] - L[4] sympathetic ganglia with peak frequency in L[4] sympathetic ganglion. The somal diameters of motoneurons forming the femoral nerve ranged between 10 and 58 [micro]m with majority having somal diameters greater than 25 [micro]m. The size spectrum of sensory neurons measure between 14 and 60 [micro]m. The sympathetic neurons measure between 10 and 44[micro]m