Curriculum: Animal and Human Biology, and Ecology

Supervisor: Maria Cristina Follesa

Co-Supervisor: Saturnino Spiga

Curriculum Vitae

Riccardo received his bachelor’s degree in biology at University of Cagliari in 2016, with a thesis entitled “Colocalization of alpha-2A adrenegic receptors in the ventral tegmental area”, supervised by Prof. Saturnino Spiga. The thesis was focused on the putative noradrenergic control on the mesolimbic system in the rat brain. In particular, he took part to the neuroanatomical surveys, working on the 3D confocal reconstructions.

He earned his master’s degree in marine Bio-ecology with the highest honours from the University of Cagliari in 2018. Prof. Saturnino Spiga supervised the thesis titled “Effects of Caulerpa cylindracea (Sonder, 1845) withdrawal in diencephalic neurons of Diplodus sargus (Linneus, 1758) brain.” This thesis study was inspired by the well-known behaviour of the omnivorous fish D. sargus, which can become a selective feeder of the algae C. cylindracea, an invasive species of the Mediterranean Sea that has a negative impact on the D. sargus. Notably, the study focused on the neuroanatomical effects of C. cylindracea withdrawal on a specific group of dopaminergic neurons implicated in the fish’s reward system, explaining a part of the mechanisms involved in this food seeking and intake. Riccardo did not limit himself to marine biology for the duration of his internship. He gained experience in histology procedures by interning in the old neuroanatomy laboratory, which ranged from the smallest fish brains to the largest human brains, taking part in a collaboration between University of Cagliari and USA research group (NeuroDigiTech).

After the graduation, he presented his thesis work at the project’s concluding conference, “Impact of invasive alien species on Sardinian ecosystems,” in which his supervisor was a co-author.

In 2019 won a research scholarship for the project “New methods for visualization and characterization of human neurons (post-mortem)”, supervised by Prof. Saturnino Spiga. This project focused on using long-preserved human brain tissue in formalin to combine the Golgi staining and immunofluorescence, making these tissues accessible for the study of human brain diseases. The obtained results were presented during the conference “Italian Group for the Study of Neuromorphology (2020)”. The presented scientific contribution was awarded with a price for one of the best young researcher’s lines.

Since 2022, he has been a collaborator for the Italian “National Inter-university Consortium for Marine Sciences”, participating to the collecting of meristic data in research fishing campaigns in the seas surrounding Sardinia (GSA 11), linked to the MEDITS european program.

Nowadays, Riccardo is a PhD student at Cagliari University, under the supervision of Prof. Maria Cristina Follesa and Prof. Saturnino Spiga. His current research focuses on the neuroecology of cartilaginous fish, with particular interest on the brain pituitary gonadal system, with the main aim of characterizing the anatomical changes in the reproductive cycles.

Research Topic

Neuroecology of cartilaginous fish, with particular interest on the brain pituitary gonadal system

Abstract

Riccardo Porceddu's research project aims to expand the knowledge on the Brain-Pituitary-Gonad (BPG) system in cartilaginous fish (Chondrichthyans), which are considered among the oldest existing vertebrates with a crucial ecological role. Despite their importance and their foundational position in vertebrate phylogeny, many aspects of their biology and reproduction remain understudied. Their slow growth rates, late maturity, and low fecundity also make them highly susceptible to anthropogenic impact, such as increasing fishing pressure, leading to a significant decline in populations, especially in the Mediterranean Sea, an extinction risk hotspot for these species.

The primary goal is to gather new anatomical information with functional implications within the BPG system, focusing on the analysis of neurons and involved structures in one or more model species, comparing juvenile, sub-adult, and adult individuals. Cartilaginous fish samples will be obtained from MEDITS fishing campaigns and commercial landings in Sardinian waters. Tissues (brains, gonads, and other relevant areas) will be processed for histology and microscopic analysis to identify changes in the BPG system related to sexual maturity.

The expected plasticity of the BPG system based on maturational stage and the diversity in brain models are anticipated to help understand the wide variety of reproductive cycles among Chondrichthyans and their adaptation to different environments. The results of this basic research aim to increase useful information for the management and conservation of these threatened species and raise awareness about their evolutionary aspects, providing a foundation for future studies on the impact of climate change or pollution on the BPG system.

Publications

IRIS: https://iris.unica.it/cris/rp/rp60724

ORCID: https://orcid.org/0000-0001-7782-7549

Conference Contributions

Pusceddu A., Mulas G., Porceddu R., Cau A., Moccia D., Spiga S. “Food addicted fish: impact of the invasive alien algae C. cylindracea Sonder on the central nervous system of D. sargus “. Congress presentation: XXIV Congresso dell’Associazione Italiana di Oceanologia e Limnologia (2019).

Spiga S., Mulas G., Porceddu R., Pusceddu A. “Effetti di Caulerpa Cylindracea sul sistema nervoso centrale di Diplodus sargus”. Congress presentation: Impact of Invasive Alien Species on Sardinian Ecosystems (2019).

Porceddu R., Porcu C., Mulas G., Spiga S., Follesa M.C. “Sexual maturity changes in neuronal plasticity of the catecholaminergic preoptic region in the small spotted catshark female’s brain”. Congress Poster: 82° congresso dell’Unione Zoologica Italiana (2023).