DNp01 [FBbt_00004020]

DNp01

ID: FBbt_00004020

Large adult descending neuron that controls jump escape behavior (Thomas and Wyman, 1984).There is one of these cells per hemisphere (Koto et al., 1981; Namiki et al., 2018; Sturner et al., 2025) and its large cell body is located posterior to the lower protocerebrum (Koto et al., 1981). It can be identified by its large descending axon (Power, 1948), which is several times larger than any other axon in the cervical connective (Koto et al., 1981). It enters the cervical connective via the posterior cerebro-cervical fascicle (Ito et al., 2014) and descends on the ipsilateral side (Koto et al., 1981; Namiki et al., 2018), in the dorsal cervical fasciculus (Power, 1948). In the brain, it has dendritic arborization in the ipsilateral zones A and B of the antennal mechanosensory and motor center (Kamikouchi et al., 2009; Matsuo et al., 2016), where it receives substantial input from zone A and B Johnston organ neurons (Kim et al., 2020). It also arborizes in the posterior ventrolateral protocerebrum and gorget (Matsuo et al., 2016; Namiki et al., 2018). It enters the VNC near the dorsal midline and extends posteroventrally to the mesothoracic neuromere, where it turns ventrolaterally, and ends abruptly without branching (Koto et al., 1981). In the mesothoracic neuromere, it forms electrical synapses with downstream motor and premotor neurons at the inframedial bridge, where the two giant fiber neurons connect across the midline, and at the axonal lateral bend (King and Wyman, 1980; Allen et al., 1998; Kennedy and Broadie, 2018). It is a primary neuron (Allen et al., 1998; Dorkenwald et al., 2024; Schlegel et al., 2024).

Some components identified by Power (1948) later found to be electrically-coupled neurons (King and Wyman, 1980; Phelan et al., 1996).