Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ, UK.
Champalimaud Neuroscience Program, Champalimaud Centre for the Unknown, Lisbon, Portugal.
J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2020 Nov;206(6):921-938. doi: 10.1007/s00359-020-01448-0. Epub 2020 Oct 21.
Chirping male crickets combine a 30 Hz pulse pattern with a 3 Hz chirp pattern to drive the rhythmic opening-closing movements of the front wings for sound production. Lesion experiments suggest two coupled modular timer-networks located along the chain of abdominal ganglia, a network in A3 and A4 generating the pulse pattern, and a network organized along with ganglia A4-A6 controlling the generation of the chirp rhythm. We analyzed neurons of the timer-networks and their synaptic connections by intracellular recordings and staining. We identified neurons spiking in phase with the chirps and pulses, or that are inhibited during the chirps. Neurons share a similar "gestalt", regarding the position of the cell body, the dendritic arborizations and the contralateral ascending axon. Activating neurons of the pulse-timer network elicits ongoing motor activity driving the generation of pulses; this activity is not structured in the chirp pattern. Activating neurons of the chirp-timer network excites pulse-timer neurons; it drives the generation of chirps and during the chirps the pulse pattern is produced. Our results support the hypothesis that two modular networks along the abdominal ganglion chain control the cricket calling song, a pattern generating network in the mesothoracic ganglion may not be required.
雄性蟋蟀通过发出 30Hz 的脉冲模式和 3Hz 的啁啾模式来驱动前翅的有节奏的开合运动，从而产生声音。损伤实验表明，两个耦合的模块化计时器网络位于腹部神经节链上，A3 和 A4 中的网络产生脉冲模式，而沿着 A4-A6 神经节组织的网络控制啁啾节奏的产生。我们通过细胞内记录和染色分析了计时器网络及其突触连接的神经元。我们鉴定了与啁啾和脉冲相位同步或在啁啾过程中被抑制的神经元。神经元具有相似的“整体形态”，包括细胞体的位置、树突分支和对侧上升轴突。激活脉冲计时器网络的神经元会引发持续的运动活动，从而产生脉冲；这种活动不是按照啁啾模式组织的。激活啁啾计时器网络的神经元会激发脉冲计时器神经元；它驱动啁啾的产生，并且在啁啾期间会产生脉冲模式。我们的结果支持了这样一种假设，即沿着腹部神经节链的两个模块化网络控制蟋蟀的叫声，胸部神经节中的模式生成网络可能不是必需的。
