Mario Gozzano: The Work of an EEG Pioneer

The study of the early history of electroencephalography can yield fascinating insights and surprises. A revisit to the work of Mario Gozzano (1898–1986) has proved to be particularly stimulating. His EEG study of 1935 is a classic and should be resurrected from the graveyard of history. Gozzano was an eminent clinical neurologist-epileptologist and chairman of the neurological-psychiatric university departments in Cagliari, Pisa, Bologna and, from 1951 to his retirement, in Rome. He quickly recognized the significance of EEG and produced his major experimental EEG work in the wake of a stay at the Berlin-Buch Brain Institute. His prolonged corticograms of various regions in the rabbit demonstrated striking differences between various cortical areas. Topical cortical strychnine produced spikes (a barely known phenomenon at that time) and the evolution from interictal to ictal spiking. Spikes induced by visual stimuli may be regarded as precursors of evoked potentials. While Hans Berger was a holist (“the brain working as a whole”), Gozzano (influenced by Vogt and Kornmueller) provided EEG support for the localizationists.

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Penfield’s Homunculus and Other Grotesque Creatures from the Land of If

Nuncius ◽

10.1163/182539112x637192 ◽

2012 ◽

Vol 27 (1) ◽

pp. 141-162 ◽

Cited By ~ 8

Author(s):

Claudio Pogliano

Keyword(s):

Functional Organization ◽

The Body ◽

Medical Texts ◽

Montreal Neurological Institute ◽

Surgical Ablation ◽

Cortical Areas ◽

History Of ◽

Mcgill University ◽

The Brain ◽

Different Parts

The neurosurgeon Wilder Graves Penfield (1891-1976) helped to develop a surgical treatment for epilepsy and used his results to investigate the functional organization of the brain. He was instrumental in founding the Montreal Neurological Institute at McGill University, which he directed from 1934 to 1960. There he studied, with his collaborators, the effects of stimulation and surgical ablation on different parts of the brain in order to localize their somatosensory functions. To visualize the results of this research, Hortense Pauline Cantlie drew images of a homunculus whose proportions reflected the extent of the cortical areas controlling different parts of the body. These images were published by Penfield in 1937; a modified version followed in 1950, opening the way for such developments as the diagrams of mammalian brains drawn by the neurophysiologist Clinton N. Woolsey in 1958. This article will reconstruct the history of Penfield’s map of the human brain, which was utilized in medical texts for many decades, but which eventually would be severely criticized.

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The mouse cortico-basal ganglia-thalamic network

10.1101/2020.10.06.326876 ◽

2020 ◽

Author(s):

Nicholas N. Foster ◽

Laura Korobkova ◽

Luis Garcia ◽

Lei Gao ◽

Marlene Becerra ◽

...

Keyword(s):

Basal Ganglia ◽

Functional Organization ◽

Network Motif ◽

Dorsal Striatum ◽

Thalamic Nuclei ◽

Cortical Areas ◽

Neuropsychiatric Diseases ◽

History Of ◽

Input Source ◽

The Brain

ABSTRACTThe cortico-basal ganglia-thalamic loop is one of the fundamental network motifs in the brain. Revealing its structural and functional organization is critical to understanding cognition, sensorimotor behavior, and the natural history of many neurological and neuropsychiatric diseases. Classically, the basal ganglia is conceptualized to contain three primary information output channels: motor, limbic, and associative. However, given the roughly 65 cortical areas and two dozen thalamic nuclei that feed into the dorsal striatum, a three-channel view is overly simplistic for explaining the myriad functions of the basal ganglia. Recent works from our lab and others have subdivided the dorsal striatum into numerous functional domains based on convergent and divergent inputs from the cortex and thalamus. To complete this work, we generated a comprehensive data pool of ∼700 injections placed across the striatum, external globus pallidus (GPe), substantia nigra pars reticulata (SNr), thalamic nuclei, and cortex. We identify 14 domains of SNr, 36 in the GPe, and 6 in the parafascicular and ventromedial thalamic nuclei. Subsequently, we identify 6 parallel cortico-basal ganglia-thalamic subnetworks that sequentially transduce specific subsets of cortical information with complex patterns of convergence and divergence through every elemental node of the entire cortico-basal ganglia loop. These experiments reveal multiple important novel features of the cortico-basal ganglia network motif. The prototypical sub-network structure is characterized by a highly interconnected nature, with cortical information processing through one or more striatal nodes, which send a convergent output to the SNr and a more parallelized output to the GPe; the GPe output then converges with the SNr. A domain of the thalamus receives the nigral output, and is interconnected with both the striatal domains and the cortical areas that filter into its nigral input source. This study provides conceptual advancement of our understanding of the structural and functional organization of the classic cortico-basal ganglia network.

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Some early history of replica techniques for electron microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100130018 ◽

1992 ◽

Vol 50 (2) ◽

pp. 1076-1077

Author(s):

Robert M. Fisher

Keyword(s):

Thin Film ◽

Electron Microscopy ◽

Optical Microscope ◽

Early History ◽

Bulk Materials ◽

Thin Sections ◽

Transmission Electron ◽

Reflected Light ◽

History Of ◽

Electron Microscopes

By 1940, a half dozen or so commercial or home-built transmission electron microscopes were in use for studies of the ultrastructure of matter. These operated at 30-60 kV and most pioneering microscopists were preoccupied with their search for electron transparent substrates to support dispersions of particulates or bacteria for TEM examination and did not contemplate studies of bulk materials. Metallurgist H. Mahl and other physical scientists, accustomed to examining etched, deformed or machined specimens by reflected light in the optical microscope, were also highly motivated to capitalize on the superior resolution of the electron microscope. Mahl originated several methods of preparing thin oxide or lacquer impressions of surfaces that were transparent in his 50 kV TEM. The utility of replication was recognized immediately and many variations on the theme, including two-step negative-positive replicas, soon appeared. Intense development of replica techniques slowed after 1955 but important advances still occur. The availability of 100 kV instruments, advent of thin film methods for metals and ceramics and microtoming of thin sections for biological specimens largely eliminated any need to resort to replicas.

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