Figure 5. γ-Motoneurons are sensitive to lower concentrations of ouabain than α-motoneurons. Electrophysiological recordings were made from cells confirmed as motoneurons by their morphology (A, B) and their basic electrophysiological responses to depolarizing and hyperpolarizing current pulses (A1, B1). Cells were confirmed as either α- or γ-motoneurons based upon and their response to the 5HT1D agonist L694247 (10 μm, A2 and B2, n = 5 and 8, respectively). γ-Motoneurons, which responded to L694247, also responded to 3 μm ouabain (B3, n = 8) and 30 μm ouabain (B4, n = 3). α-Motoneurons, which did not respond to L694247, did not respond to 3 μm ouabain (A3, n = 5) but did respond to 30 μm ouabain (A4, n = 5). Group data comparing these responses is shown in C, black bars = α-motoneurons and white bars = γ-motoneurons. *p < 0.05, **p < 0.01, ***p < 0.005.