Marcello Brunelli
{{Short description|Italian neurophysiologist}}
{{Infobox scientist
| birth_name = Marcello Brunelli
| image = Brunelli Marcello.jpg
| caption =
| birth_date = {{birth date|1939|04|14|df=y}}
| death_date = {{Death date and age|2020|11|25|1939|04|14|df=y}}
| death_place = Pisa, Italy
| fields = Neuroscience
| workplaces = University of Pisa
| known_for = Physiology of learning and memory
}}
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 and worked with Giuseppe Moruzzi and Eric Kandel. Together with Kandel, he obtained the first demonstration of the role of the cyclic AMP as a second messenger in the transmission of the nervous impulse.{{cite journal |last1=Brunelli |first1=M |last2=Castellucci |first2=V |last3=Kandel |first3=E. |title=Synaptic facilitation and behavioral sensitization in Aplysia: possible role of serotonin and cyclic AMP |journal=Science |date=10 December 1976 |volume=194 |issue=4270 |pages=1178–1181 |doi=10.1126/science.186870|pmid=186870 |bibcode=1976Sci...194.1178B }}
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 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 Pisa, on 25 November 2020, aged 81, from complications associated with COVID-19.{{Cite web|url=https://www.ilrestodelcarlino.it/ancona/cronaca/addio-marcello-brunelli-luminare-della-fisiologia-1.5756467|title=Addio Marcello Brunelli, luminare della fisiologia|date=27 November 2020}}
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{{cite journal |last1=Bagnoli |first1=P |last2=Brunelli |first2=M |last3=Magni |first3=F |title=A fast conducting pathway in the central nervous system of the leech Hirudo medicinalis. |journal=Archives Italiennes de Biologie |date=May 1972 |volume=110 |issue=1 |pages=35–51 |pmid=5050121}} and visual perception in the common pigeon.{{cite journal |last1=Giorgetti de Britto |first1=L.R. |last2=Brunelli |first2=M. |last3=Francesconi |first3=W. |last4=Magni |first4=F. |title=Visual response pattern of thalamic neurons in the pigeon |journal=Brain Research |date=October 1975 |volume=97 |issue=2 |pages=337–343 |doi=10.1016/0006-8993(75)90455-2|pmid=1175051 |s2cid=44697245 }}
His research activity subsequently focused on the study of the neurobiological mechanisms of memory and non-associative learning in animal models. One of the main contributions of Brunelli was the identification of the cyclic AMP as the second messenger in nerve impulse transduction. In the mid-seventies it was known that serotonin 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{{cite journal |last1=SUTHERLAND |first1=EARL W. |last2=ROBISON |first2=G. ALAN |last3=BUTCHER |first3=REGINALD W. |title=Some Aspects of the Biological Role of Adenosine 3',5'-monophosphate (Cyclic AMP) |journal=Circulation |date=February 1968 |volume=37 |issue=2 |pages=279–306 |doi=10.1161/01.CIR.37.2.279|doi-access=free }} – directly into the presynaptic terminal and observed that nerve transmission was facilitated.{{cite journal |last1=Kandel |first1=Eric R. |title=NOBEL LECTURE: The Molecular Biology of Memory Storage: A Dialog Between Genes and Synapses |journal=Bioscience Reports |date=1 October 2001 |volume=21 |issue=5 |pages=565–611 |doi=10.1023/A:1014775008533|pmid=12168768 |s2cid=35753311 }}
{{quote|This provided the most compelling evidence then available that cyclic AMP is involved in a specific physiological function in the nervous system and gave us an initial understanding of the molecular mechanisms of short-term memory.|Eric R. Kandel}}
During the 1980s Brunelli continued his studies on the role of serotonin and intracellular calcium in synaptic modulation in the leech.{{cite journal |last1=Garcia-Gil |first1=Mercedes |last2=Berton |first2=Fulvia |last3=Tongiorgi |first3=Enrico |last4=Brunelli |first4=Marcello |title=Effects of Cyclic Nucleotides and Calcium/Calmodulin on Protein Phosphorylation in the CNS of Hirudo medicinalis |journal=Journal of Neurochemistry |date=March 1989 |volume=52 |issue=3 |pages=699–704 |doi=10.1111/j.1471-4159.1989.tb02511.x|pmid=2465376 |s2cid=38536508 }}{{cite journal |last1=Catarsi |first1=S. |last2=Garcia-Gil |first2=M. |last3=Traina |first3=G. |last4=Brunelli |first4=M. |title=Seasonal variation of serotonin content and nonassociative learning of swim induction in the leech Hirudo medicinalis |journal=Journal of Comparative Physiology A |date=September 1990 |volume=167 |issue=4 |pages=469–474 |doi=10.1007/BF00190817|pmid=2258835 |s2cid=20513327 }}{{cite journal |last1=Catarsi |first1=S |last2=Scuri |first2=R |last3=Brunelli |first3=M |title=Cyclic AMP mediates inhibition of the Na(+)-K+ electrogenic pump by serotonin in tactile sensory neurones of the leech. |journal=The Journal of Physiology |date=1 March 1993 |volume=462 |issue=1 |pages=229–242 |doi=10.1113/jphysiol.1993.sp019552|pmid=7687293 |pmc=1175298 }} The nervous system of this annelid consists of a chain of interconnected ganglia that contain relatively large and easily accessible neurons, lending itself well to electrophysiological recording.{{cite journal |last1=Wagenaar |first1=D. A. |title=A classic model animal in the 21st century: recent lessons from the leech nervous system |journal=Journal of Experimental Biology |date=4 November 2015 |volume=218 |issue=21 |pages=3353–3359 |doi=10.1242/jeb.113860|pmid=26538172 |doi-access=free }} This has made it possible to make great progress in understanding the mechanisms of habituation and sensitization.{{cite journal |last1=Brunelli |first1=M |last2=Garcia-Gil |first2=M |last3=Mozzachiodi |first3=R |last4=Scuri |first4=R |last5=Zaccardi |first5=ML |title=Neurobiological principles of learning and memory. |journal=Archives Italiennes de Biologie |date=January 1997 |volume=135 |issue=1 |pages=15–36 |pmid=9139580}} In a series of experimental studies his group identified the role of acetyl-L-carnitine in influencing neuronal gene expression.{{cite journal |last1=Traina |first1=G |last2=Valleggi |first2=S |last3=Bernardi |first3=R |last4=Rizzo |first4=M |last5=Calvani |first5=M |last6=Nicolai |first6=R |last7=Mosconi |first7=L |last8=Durante |first8=M |last9=Brunelli |first9=M |title=Identification of differentially expressed genes induced in the rat brain by acetyl-l-carnitine as evidenced by suppression subtractive hybridisation |journal=Molecular Brain Research |date=December 2004 |volume=132 |issue=1 |pages=57–63 |doi=10.1016/j.molbrainres.2004.09.006|pmid=15548429 }}{{cite journal |last1=Traina |first1=G |last2=Bernardi |first2=R |last3=Cataldo |first3=E |last4=Macchi |first4=M |last5=Durante |first5=M |last6=Brunelli |first6=M |title=In the Rat Brain Acetyl-l-carnitine Treatment Modulates the Expression of Genes Involved in Neuronal Ceroid Lipofuscinosis |journal=Molecular Neurobiology |date=23 August 2008 |volume=38 |issue=2 |pages=146–152 |doi=10.1007/s12035-008-8038-8|pmid=18726077 |s2cid=7637059 }}{{cite journal |last1=Traina |first1=G |last2=Federighi |first2=G |last3=Macchi |first3=M |last4=Bernardi |first4=R |last5=Durante |first5=M |last6=Brunelli |first6=M |title=Modulation of Myelin Basic Protein Gene Expression by Acetyl-l-Carnitine |journal=Molecular Neurobiology |date=26 May 2011 |volume=44 |issue=1 |pages=1–6 |doi=10.1007/s12035-011-8189-x|pmid=21614517 |s2cid=11952065 }}
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 that induces a sustained reduction of heart rate and mean arterial pressure.{{cite journal |last1=Schaller |first1=B. |title=Trigeminocardiac reflex |journal=Journal of Neurology |date=June 2004 |volume=251 |issue=6 |pages=658–665 |doi=10.1007/s00415-004-0458-4|pmid=15311339 |s2cid=189865162 }} Brunelli and colleagues observed the activation of the reflex following mandibular stretching in humans.{{cite journal |last1=Brunelli |first1=M |last2=Coppi |first2=E |last3=Tonlorenzi |first3=D |last4=Del Seppia |first4=C |last5=Lapi |first5=D |last6=Colantuoni |first6=A |last7=Scuri |first7=R |last8=Ghione |first8=S |title=Prolonged hypotensive and bradycardic effects of passive mandibular extension: evidence in normal volunteers. |journal=Archives Italiennes de Biologie |date=December 2012 |volume=150 |issue=4 |pages=231–7 |doi=10.4449/aib.v150i4.1420 |doi-broken-date=1 November 2024 |pmid=23479456}} Further experiments on the rat have shown a concurrent vasodilation of pial arterioles.{{cite journal |last1=Lapi |first1=D |last2=Colantuoni |first2=A |last3=Del Seppia |first3=C |last4=Ghione |first4=S |last5=Tonlorenzi |first5=D |last6=Brunelli |first6=M |last7=Scuri |first7=R |title=Persistent effects after trigeminal nerve proprioceptive stimulation by mandibular extension on rat blood pressure, heart rate and pial microcirculation. |journal=Archives Italiennes de Biologie |date=March 2013 |volume=151 |issue=1 |pages=11–23 |doi=10.4449/aib.v151i1.1470 |doi-broken-date=1 November 2024 |pmid=23807620}}