02056nas a2200169   4500008004100000245016200041210006900203520138200272653002601654653003101680653002401711653002001735653003101755100002301786700002101809856005601830       2019                        eng d00aFeedforward discharges couple the singing central pattern generator and ventilation central pattern generator in the cricket abdominal central nervous system0 aFeedforward discharges couple the singing central pattern genera3 a<p>We investigated the central nervous coordination between singing motor activity and abdominal ventilatory pumping in crickets. Fictive singing, with sensory feedback removed, was elicited by eserine-microinjection into the brain, and the motor activity underlying singing and abdominal ventilation was recorded with extracellular electrodes. During singing, expiratory abdominal muscle activity is tightly phase coupled to the chirping pattern. Occasional temporary desynchronization of the two motor patterns indicate discrete central pattern generator (CPG) networks that can operate independently. Intracellular recordings revealed a sub-threshold depolarization in phase with the ventilatory cycle in a singing-CPG interneuron, and in a ventilation-CPG interneuron an excitatory input in phase with each syllable of the chirps. Inhibitory synaptic inputs coupled to the syllables of the singing motor pattern were present in another ventilatory interneuron, which is not part of the ventilation-CPG. Our recordings suggest that the two centrally generated motor patterns are coordinated by reciprocal feedforward discharges from the singing-CPG to the ventilation-CPG and vice versa. Consequently, expiratory contraction of the abdomen usually occurs in phase with the chirps and ventilation accelerates during singing due to entrainment by the faster chirp cycle.</p>
10aAbdominal ventilation10aCentral pattern generation10aCorollary discharge10aFictive singing10aMotor systems coordination1 aSchöneich, Stefan1 aHedwig, Berthold  uhttp://link.springer.com/10.1007/s00359-019-01377-7