Higher mitochondrial density in slow versus fast lobster sensory neurons.

The stretch-sensitive muscle receptor organ (MRO) in the abdomen of the lobster Homarus americanus contains an identifiable fast and a slow sensory neuron. Morphometric analysis of electron micrographs of areas through the somata of these neurons revealed a higher density of mitochondria in the slow versus the fast cell (19 vs 15%). Such differences in oxidative capacity are closely matched with differences in their physiological performances.