Analysis of the Neural Network Regulating the Cardio-Renal System in the Central Nervous System ofHelix pomatiaL.

Abstract

In the central nervous system of Helix pomatia 22 cells taking part in the regulation of the cardio-renal system have been identified. These cells are scattered throughout the visceral and right parietal ganglia. Among identified cells sensory, motor, and interneurons were found and the hierarchical character of the network was stated. The network regulating heart activity was found to be of the over-guaranteed, convergent type, where the inputs predominate and the outputs form independent, parallel pathways, being coordinated by interneurons. This neural network can be divided into two levels: collectors and coordinators, which are responsible for the conduction or analysis of the afferent inputs, respectively. The localization of identified cells was studied by intracellular and retrograde injection of CoCl2. Primary sensory cells were found to be bipolar, motoneurones and interneurones were unipolar or pseudo-unipolar with rich arborization within the ganglia. Interneuron V21 showed a phasic or tonic pattern of firing. The phasic activity of the neuron V21 appeared as a burst correlated with the individual heartbeats. The tonic pattern of firing was caused by activation of various inputs of the cardio-renal system and led always to the stopping of the heartbeat. The network regulating the heartbeat was organized around the interneurones. In the activity pattern of the interneurones the origin of the input was not distinguishable; however, on the middle level of the system it can be verified. These cells play a role in the storage of information originating Irom various receptor areas. According to this the regulatory network can be divided into subsystems.