As I have pointed out earlier, when I met Oliver Zangwill in 1961 at a meeting on dyslexia in Baltimore, he listened patiently to the exposition of my ideas on the significance of the cortico-cortical connections for the higher functions. A short time later, while on a trip to Boston, he suggested to me that I should prepare an extended account of these ideas. This paper would never have been written without Professor Zangwill’s urging, and I am grateful to him for having brought me to a more careful review of the older literature and a more precise statement of my own ideas. Although Russell Brain, who was then the editor of Brain, had some misgivings about the section on philosophical implications he agreed to take the manuscript unchanged.

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Disconnexion syndromes in animals and man

The Prefrontal Cortex, Fifth Edition, provides users with a thoroughly updated version of this comprehensive work that has historically served as the classic reference on this part of the brain. The book offers a unifying, interdisciplinary perspective that is lacking in other volumes written about the frontal lobes, and is, once again, written by the award-winning author who discovered "memory cells," the physiological substrate of working memory. The fifth edition constitutes a comprehensive update, including all the major advances made on the physiology and cognitive neuroscience of the region since publication in 2008. All chapters have been fully revised, and the overview of prefrontal functions now interprets experimental data within the theoretical framework of the new paradigm of cortical structure and dynamics (the Cognit Paradigm), addressing the accompanying social, economic, and cultural implications. * Provides a distinctly interdisciplinary view of the prefrontal cortex, covering all major methodologies, from comparative anatomy to modern imaging* Unique analysis and synthesis of a large body of basic and clinical data on the subject (more than 2000 references)* Written by an award-winning author who discovered "memory cells," the physiological substrate of working memory* Synthesizes evidence that the prefrontal cortex constitutes a complex pre-adaptive system* Incorporates emerging study of the role of the frontal lobes in social, economic, and cultural adaptation

The prefrontal cortex

Efferent connections of the parabrachial nucleus in the rat.

1. Cat retinal ganglion cells may be subdivided into sustained and transient response-types by the application of a battery of simple tests based on responses to standing contrast, fine grating patterns, size and speed of contrasting targets, and on the presence or absence of the periphery effect. The classification is equivalent to the ;X'/;Y' (linear/nonlinear) subdivision of Enroth-Cugell & Robson which is thus confirmed and extended.2. The sustained/transient classification applied to both on-centre and off-centre cells.3. Lateral geniculate neurones may be similarly classified by the same tests. Occasional concentrically organized cells had a mixture of sustained and transient properties.4. A technique for simultaneous recording from a geniculate neurone and one or more retinal ganglion cells providing its excitatory input showed that the connexions were specific with respect to the sustained/transient classification as well as the on-centre/off-centre classification. Most geniculate neurones are excitatorily driven only by retinal ganglion cells of the same functional type. In a few cases the inputs were mixed but only with respect to the sustained/transient classification.5. Sustained retinal ganglion cells had slower-conducting axons than the transient type. The same was true for lateral geniculate neurones but in this case the distributions showed considerable overlap.6. The sustained/transient classification is the functional correlate for the well-known segregation of optic nerve fibres into two conduction groups.7. The pathways carrying sustained and transient information remain essentially separate from retina through the lateral geniculate nucleus to the striate cortex.

Sustained and transient neurones in the cat's retina and lateral geniculate nucleus.

In the same year in which Gowers wrote the prophetic statement quoted above, Bechterew on the basis of mylogenetic studies described two ascending fibre systems in the anterolateral funiculus of the spinal cord, two systems that were directly continuous into the reticular formation of the brain-stem. These two pathways consisted of a medial “ground bundle” of the lateral funiculus and a more lateral system of “the rest of the lateral funiculus,” exclusive of the dorsal spinocerebellar tract of Flechsig (text-fig. 1).

Ascending axon degeneration following anterolateral cordotomy. An experimental study in the monkey.

A stereotaxic atlas of the diencephalon of the cat

IN THIS symposium, Professor Magoun has described some of the properties of the reticular system of the brain stem, with particular reference to mechanisms underlying alertness or arousal of the organism and its effect upon the electrical activity of the cortex. Emphasis has been placed upon that portion of this system lying in the basal part of the diencephalon and midbrain, with some extension into the mesial portion of the thalamus. From the results presented it would seem that the ascending portion of the reticular system in the more caudal part of the brain stem exerts its effect upon the electrical activity of the cortex in a generalized manner, without evidence of topographic localization. In the thalamus there exists a more highly differentiated portion of this system, which we have tentatively described as the thalamic reticular system. Electrical stimulation within this system is capable of exerting a similar activating influence

Cosimo Ajmone-Marsan

Papers

A stereotaxic atlas of the diencephalon of the cat

Corticofugal projections to the brain stem.