Some Characteristics of Neurons in the Reticular Nucleus of the Thalamus (Preliminary Data)

Abstract

Our general understanding of the function of neurons is that dendrites receive information that is relayed to the axon, where action potentials are initiated and propagated to eventually trigger neurotransmitter release at synaptic terminals. Although for a number of neuron types in the mammalian brain, many neuron types do not follow this classical polarity pattern. In fact, dendrites may be the site of action potentials initiation and propagation. It should be noted that convincing evidence has been obtained for the existence of dendritic action potentials in hippocampal and neocortical neurons. With regard to the dendrite potentials of thalamic neurons in general and specifically the reticular nucleus of the thalamus, it has not yet been reported. The results of this study demonstrate, for the first time, that generation of spike potentials of different amplitudes was observed in the activity of the thalamic reticular nucleus neurons. The generation of one action potential does not interfere with the generation of another, and a spike potential of smaller amplitude can occur at the ascending or descending phase of the spike potential of large amplitude. It can be argued that the spike potentials of lower amplitudes arising in the thalamic reticular nucleus neuron are of dendrite origin. Given both the strategic position and the functional purpose of the TRN, it can be assumed that the neurons of this structure must each time be discharged with spike potentials in order to carry out their modulating effect on other areas of the nervous system of the brain without leakage.