Features of morphofunctional rehabilitation of Mauthner neurons after fatigue

Structural reorganization of smooth endoplasmic reticulum (SER) in relation to changes in functional state of neurons has been investigated using fatigue and subsequent rhabilitation of the goldfish Mauthner (M-) cells as experimental approach. The recovery of original structure of SER in distal parts of dendrities after its significant proliferation, caused by a 3 h natural stimulation, markedly retarded, as compared with quickly normalized functional activity of M-cells. At the same time in somata and proximal parts of dendrites the structural recovery of SER coincided with restoration of the initial function of M-cells. The results suggest that within a single neuron SER with its obvious structural plastisity the neuron functional activoty is supported and restored through regulating the extent of proliferation angmenting Ca(2+)-accumulation in its compartments. Nevertheless SER posseses certain autonomy in structural recovery within somata and dendrites. Such differences of SER plasticity in different parts of the same neuron presumable reflect differences in interaction of its individual compartments with the cytoskeleton and adjacent cytoplasm, or may be caused by different activity of synapses situated on the soma and dendrites.