Dopamine Improves Resistance of Dendrites of Mauthner Neurons to Destruction Induced by Sensory Stimulation and Application of Β-Amyloid.

Mauthner neurons in goldfish fry were studied by the methods of light and electron microscopy. The structure and volume of individual dendrites as well as the structure of axodendritic synapses were examined using virtual images of neurons formed from serial 3-μ sections. In short-time (5 h) experiments with application of dopamine, β-amyloid fragment (25-35), and long-term sensory stimulation affecting afferent inputs to Mauthner neurons, the dendrites were larger than the same dendrites under the same conditions without dopamine application. Application of dopamine induced no pathological changes in the structure of axodendritic chemical and electric synapses containing desmosome-like contacts.