An electron microscopic survey of the nervous system of the planarian Dugesia tigrina (agamic strain) has revealed the presence of three presumptive types of neurons giving rise to as many nerve fibre types: cholinergic motor neurons, aminergic sensory neurons (or interneurons) and peptidergic neurosecretory neurons. It has been found that aminergic nerve fibres form efferent synapses on either cholinergic or peptidergic nerve fibres. These latter, in turn, show omegashaped, neurosecretory release sites in axon areas post-synaptic with respect to aminergic terminals.
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Con il contributo del Ministero per i Beni e le Attività Culturali