Topographic distribution of the recording sites of 53 acceleration-sensitive neurons and 34 acceleration-insensitive neurons in the pigeon's nucleus lentiformis mesencephali (nLM), which is divided into medial or magnocellular (nLMm) and lateral or parvocellular (nLMl) divisions. A, Schematic diagram shows the location of nLM in a cross section of the pigeon's brain. The area framed by a rectangle is enlarged in C showing the distribution. B, Histological cross section shows the dye-marked location of an acceleration-sensitive neuron in nLM (C, arrow). OT, Optic tectum; nRt, nucleus rotundus; Tro, optic tract; D, dorsal; L, lateral; V, ventral; M, medial. Scale bars: A, B, 1 mm; C, 200 μm.