CONICET | Buscador de Institutos y Recursos Humanos

@font-face { font-family: "Times New Roman"; }@font-face { font-family: "Comic Sans MS"; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0in 0in 0.0001pt; font-size: 12pt; font-family: "Times New Roman"; }table.MsoNormalTable { font-size: 10pt; font-family: "Times New Roman"; }div.Section1 { page: Section1; } SEROTONERGIC MODULATION IN SENSORY-MOTOR NETWORKS OF THE LEECH M. A. Calviño Laboratorio de Fisiología y Biología Molecular. FCEyN (UBA). IFIBYNE (CONICET). Serotonin (5-HT) is a highly conserved neurotransmitter that modulates complex behaviors in different species. The distribution of release sites relative to the targets could establish a hierarchy of actions that determines the final modulatory effect. In the leech Hirudo sp., we showed that the release of 5-HT is not uniform within the ganglion but occurs at least in a discrete site close to the limit between the lateral and medial anterior packets (Calviño & Szczupak 2008). In order to analyze which is the source of serotonin involved in the fluoxetine effect, we performed an anatomical analysis of the serotonergic neurons relative to this site. We iontophoretically loaded the neurons with tetramethylrhodamine dextran and we found that both Rz and interneurons 21 and 61 are possible candidates since they all project neuropilar processes to this site. Since the reproductive ganglia (G5 and G6) have morphological variations in some serotonergic neurons, we took advantage of this situation in order to study the role of these neurons. Based on experiments performed with fluoxetine, we know that 5-HT release occurs at sexual ganglia, but it could be due to an external source. Therefore, taking into account the trace of serotonergic projections coming from adjacent ganglia, at least in G6, neurons 21 and/or 61 are the 5-HT source.