The Respiratory Centre in the Tench (Tinca Tinca L.)

Abstract

ABSTRACT The effects of brain transections on the breathing movements of the tench are described. The whole of the mid- and forebrain, and the cerebellum, can be removed without producing any change in the breathing movements. Normal movements continue after section of the IXth and Xth cranial nerves. Transections of the spinal cord and posterior medulla are without effect on the breathing rhythm until they reach a level just behind the facial lobe. The breakdown of respiration produced by transection at this level is interpreted as being due to removal of part of the respiratory centre. Rhythmically repeated movements in which the opercula abduct and the mouth closes are seen after transection in the posterior parts of the medulla. These movements are thought to be due to activity in neurones which are responsible for co-ordination of the coughs in the intact animal. These neurones are situated in the anterior part of the medulla, beneath the cerebellum.