Introduction and purpose. The disbalanse of the autonomic nervous system is involved in the pathogenesis of cardiac diseases even the sudden cardiac death. Although the rabbit is used extensively in neurocardiological research but the topography and morphology of the clusters of intrinsic cardiac neurons (ICNs) have not been examined. Therefore, the purpose of this study was to examine the distribution and the structural organization of the intrinsic cardiac neuronal clusters in the rabbit heart.
Material and methods. The cardiac nerve structures were stained histochemically for acetylcholinesterase (AChE) in whole-mount preparations derived from 11 young rabbits.
Results. The vast majority of the interconnected neuronal clusters were found at the roots of the pulmonary veins. In all examined hearts, the total number of the ICNs ranged from 1517 to 2788. The average of the neuron number of right cranial, left dorsal and ventricular groups were statistical significantly lower compared to the septal cranial, septal caudal and left cranial groups (P<0.05).
Conclusion. Both the definite loj cation of neuronal clusters and the simple structural organization, i.e. unilayered clusters with slithly expressed neuropile and lacking of fibrous capsule, have been characterised for sparse rabbit neuronal clusters. Significantly smaller neuronal number and slightly expressed neuropile in the rabbit heart, comparing to the large mammals, contribute for evidence of the predominated efferent neurons that directly influence the target-tissue in rabbit heart. These assumptions allow us to validate the use of rabbit as popular model in the experimental neuroj cardiology.
Keywords: rabbit heart, acetylcholinesterase, neuronal cluster, neurons.