Marcello Brunelli (14 July 1939 – 25 November 2020) was an Italian neurophysiologist and academic. He chaired the General Physiology and Neurobiology at the University of

Pisa Pisa ( , or ) is a city and ''comune'' in Tuscany, central Italy, straddling the Arno just before it empties into the Ligurian Sea. It is the capital city of the Province of Pisa. Although Pisa is known worldwide for its leaning tower, the cit ...

and worked with Giuseppe Moruzzi and Eric Kandel. Together with Kandel, he obtained the first demonstration of the role of the

cyclic AMP Cyclic adenosine monophosphate (cAMP, cyclic AMP, or 3',5'-cyclic adenosine monophosphate) is a second messenger important in many biological processes. cAMP is a derivative of adenosine triphosphate (ATP) and used for intracellular signal transd ...

as a

second messenger Second messengers are intracellular signaling molecules released by the cell in response to exposure to extracellular signaling molecules—the first messengers. (Intercellular signals, a non-local form or cell signaling, encompassing both first me ...

in the transmission of the nervous impulse.

Biography

In 1967, Brunelli graduated with honors in Medicine and Surgery at the University of Pisa. In the same year, he began his research activity at the CNR Institute of Clinical Physiology and from 1969 to 1970 at the Institute of Neurophysiology, also in Pisa. From 1970 to 1974, he was assistant of Human Physiology at the Pisa Physiology Institute. Together with Franco Magni he published researches on the nervous system of the pigeon and the leech and on the hormonal mechanisms of light emission in fireflies. In the two-year period 1975–76, he visited the United States, where he worked in the laboratories directed by Eric Kandel making a fundamental contribution to the studies on the intracellular mechanisms of nerve signal transduction, which will lead Kandel himself to win the Nobel Prize in Medicine in 2000. In 1976, he returned to

Italy Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical re ...

and two years later became Professor of General Physiology at the Faculty of Sciences of the University of Pisa. From 1983 to 1986, Brunelli took the place of Prof. Moruzzi at the head of the CNR Institute of Physiology in Pisa. In the following four years he was director of the Department of Physiology and Biochemistry of the University of Pisa. Brunelli died in

, on 25 November 2020, aged 81, from complications associated with

COVID-19 Coronavirus disease 2019 (COVID-19) is a contagious disease caused by a virus, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The first known case was COVID-19 pandemic in Hubei, identified in Wuhan, China, in December ...

Research activity

Brunelli began his career as a scientific researcher by investigating the nervous and hormonal mechanisms that control the emission of the luminous signals of '' Luciola lusitanica'' and demonstrating their circadian rhythms. The results of these experiments were published in a series of papers on the Archives Italiennes de Biologie from 1968 to 1973. Other studies were on the nervous system of the leech ''

Hirudo medicinalis ''Hirudo medicinalis'', the European medicinal leech, is one of several species of leeches used as "medicinal leeches". Other species of ''Hirudo'' sometimes also used as medicinal leeches include '' H. orientalis'', ''H. troctina'', and '' H. ...

'' and visual perception in the common pigeon. His research activity subsequently focused on the study of the neurobiological mechanisms of memory and

non-associative learning Learning is the process of acquiring new understanding, knowledge, behaviors, skills, values, attitudes, and preferences. The ability to learn is possessed by humans, animals, and some machines; there is also evidence for some kind of learnin ...

in animal models. One of the main contributions of Brunelli was the identification of the

as the second messenger in nerve impulse transduction. In the mid-seventies it was known that

serotonin Serotonin () or 5-hydroxytryptamine (5-HT) is a monoamine neurotransmitter. Its biological function is complex and multifaceted, modulating mood, cognition, reward, learning, memory, and numerous physiological processes such as vomiting and vas ...

acted on the terminals of sensory neurons by increasing the release of neurotransmitters into the synaptic cleft, but the mechanism of action was not known yet. Brunelli and colleagues injected cyclic AMP – whose role as a mediating molecule was well established – directly into the presynaptic terminal and observed that nerve transmission was facilitated. During the 1980s Brunelli continued his studies on the role of

and intracellular calcium in synaptic modulation in the leech. The nervous system of this annelid consists of a chain of interconnected

ganglia A ganglion is a group of neuron cell bodies in the peripheral nervous system. In the somatic nervous system this includes dorsal root ganglia and trigeminal ganglia among a few others. In the autonomic nervous system there are both sympatheti ...

that contain relatively large and easily accessible

neurons A neuron, neurone, or nerve cell is an electrically excitable cell that communicates with other cells via specialized connections called synapses. The neuron is the main component of nervous tissue in all animals except sponges and placozoa. N ...

, lending itself well to electrophysiological recording. This has made it possible to make great progress in understanding the mechanisms of habituation and sensitization. In a series of experimental studies his group identified the role of

acetyl-L-carnitine Acetyl-L-carnitine, ALCAR or ALC, is an acetylated form of L-carnitine. It is naturally produced by the human body, and it is available as a dietary supplement. Acetylcarnitine is broken down in the blood by plasma esterases to carnitine which is ...

in influencing neuronal

gene expression Gene expression is the process by which information from a gene is used in the synthesis of a functional gene product that enables it to produce end products, protein or non-coding RNA, and ultimately affect a phenotype, as the final effect. The ...

. Before retiring from academic life, Brunelli directed an interuniversity research group investigating the physiological and medical aspects of the trigeminal-cardiac reflex (TCR) associated with proprioceptive stimulation of the jaw. The TCR is a still poorly known vagal reflex activated by the stimulation of the

trigeminal nerve In neuroanatomy, the trigeminal nerve ( lit. ''triplet'' nerve), also known as the fifth cranial nerve, cranial nerve V, or simply CN V, is a cranial nerve responsible for sensation in the face and motor functions such as biting and chewin ...

that induces a sustained reduction of heart rate and mean arterial pressure. Brunelli and colleagues observed the activation of the reflex following mandibular stretching in humans. Further experiments on the

rat Rats are various medium-sized, long-tailed rodents. Species of rats are found throughout the order Rodentia, but stereotypical rats are found in the genus ''Rattus''. Other rat genera include ''Neotoma'' ( pack rats), ''Bandicota'' (bandicoot ...

have shown a concurrent vasodilation of pial arterioles.

References

{{DEFAULTSORT:Brunelli, Marcello 1939 births 2020 deaths Neurophysiologists University of Pisa alumni Academic staff of the University of Pisa People from Ancona Deaths from the COVID-19 pandemic in Tuscany