Serotonin in the lateral geniculate.

P Rinaldi; M Sutko; J H Mahnke; M Verzeano

doi:10.1016/0031-9384(75)90148-1

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Serotonin in the lateral geniculate.

P Rinaldi·M Sutko·J H Mahnke·M Verzeano

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Abstract

Serotonin was introduced, by means of a fine cannula, into the lateral geniculate body of cats immobilized with Flaxedil and artificially ventilated, while the electrical activity at the point of injection was monitored by means of microelectrodes. Doses of 1.25 to 30 mug dissolved in 0.5 to 2.0 mul of saline produced, in 2-30 min, changes in electrical activity characteristic of synchronization: increase in the rhythmicity and in the amplitude of the spontaneous gross waves and increase in the clustering of the spontaneous neuronal action potentials. At the same time the activity of neurons which produced action potentials of high amplitudes was decreased, the activity of neurons which produced action potentials of low amplitudes was increased. Action potentials of different amplitudes were produced, in this case, by neurons of different types. Thus, in the lateral geniculate as in other thalamic nuclei studied in previous investigations, the synchronization of spontaneous activity seems to require the simultaneous excitation and inhibition of two different types of neurons. The action of serotonin on activity evoked by stimulation with brief flashes of light was limited to the decrease in the amplitude of the average gross response and the inhibition of only one type of neuron. This suggests that, in the lateral geniculate body, serotonin may be implicated in different ways in the different network structures responsible for the development of spontaneous as contrasted with evoked activity.

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Action Potentials Animals Brain Mapping Cats Cerebral Cortex Dose-Response Relationship, Drug Electroencephalography Evoked Potentials Geniculate Bodies Injections Photic Stimulation Serotonin Time Factors Journal Article Research Support, U.S. Gov't, P.H.S.

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P Rinaldi, M Sutko, J H Mahnke, M Verzeano. 1975. Serotonin in the lateral geniculate.. https://doi.org/10.1016/0031-9384(75)90148-1

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