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Linda K. Gorman

Bio: Linda K. Gorman is an academic researcher from Johns Hopkins University. The author has contributed to research in topics: Hippocampus & Basal forebrain. The author has an hindex of 10, co-authored 11 publications receiving 2510 citations. Previous affiliations of Linda K. Gorman include Johns Hopkins University School of Medicine.

Papers
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Book
01 Jan 1977
TL;DR: It now appears possible to identify these circuits, localize the sites of memory storage, and analyze the cellular and molecular mechanisms of memory.
Abstract: How the brain codes, stores, and retrieves memories is among the most important and baffling questions in science. The uniqueness of each human being is due largely to the memory store—the biological residue of memory from a lifetime of experience. The cellular basis of this ability to learn can be traced to simpler organisms. In the past generation, understanding of the biological basis of learning and memory has undergone a revolution. It is clear that various forms and aspects of learning and memory involve particular systems, networks, and circuits in the brain, and it now appears possible to identify these circuits, localize the sites of memory storage, and analyze the cellular and molecular mechanisms of memory.

1,248 citations

Journal ArticleDOI
TL;DR: The results of this study suggest that the primate basal forebrain may be more involved in attentional than mnemonic processes, and that degeneration of neurons in the BFCS in cases of AD may contribute to the attention deficits observed in these individuals.
Abstract: Cognitive impairments in humans and animals have been linked to dysfunction of neurons in the basal forebrain cholinergic system (BFCS). Degeneration of these cells may be, in part, responsible for some of the cognitive deficits observed in Alzheimer's disease (AD). Although memory deficits are associated with lesions of the BFCS in rats, impairments in memory have been more subtle following similar lesions in monkeys. To evaluate the effects of BFCS lesions on cognitive processes in monkeys, we have systematically investigated the behavioral effects of ibotenic acid injections in the medial septum, nucleus of the diagonal band of Broca, and nucleus basalis of Meynert in cynomolgus monkeys, using a large series of cognitive tasks that examined different mnemonic and attentional abilities. These lesions did not impair accuracy in delayed nonmatching-to-sample, delayed response, simple or concurrent visual discriminations, spatial discriminations, or discrimination reversals. However, these lesions disrupted attentional focusing. Similar impairments in attention have been noted in patients with AD. BFCS lesions increased sensitivity to injections of the cholinergic antagonist scopolamine in a delayed nonmatching-to-sample task, indicating that the central cholinergic system was compromised in these monkeys. In concert, the results of this study suggest that the primate basal forebrain may be more involved in attentional than mnemonic processes, and that degeneration of neurons in the BFCS in cases of AD may contribute to the attention deficits observed in these individuals.

496 citations

Journal ArticleDOI
TL;DR: Male Long-Evans rats were given injections of either 192 IgG-saporin, an apparently selective toxin for basal forebrain cholinergic neurons, or vehicle into either the medial septum and vertical limb of the diagonal band or bilaterally into the nucleus basalis magnocellularis and substantia innominata, suggesting a nonmnemonic deficit.
Abstract: Male Long-Evans rats were given injections of either 192 IgG-saporin, an apparently selective toxin for basal forebrain cholinergic neurons (LES), or vehicle (CON) into either the medial septum and vertical limb of the diagonal band (MS/VDB) or bilaterally into the nucleus basalis magnocellularis and substantia innominata (nBM/SI). Place discrimination in the Morris water maze assessed spatial learning, and a trial-unique matching-to-place task in the water maze assessed memory for place information over varying delays. MS/VDB-LES and nBM/SI-LES rats were not impaired relative to CON rats in acquisition of the place discrimination, but were mildly impaired relative to CON rats in performance of the memory task even at the shortest delay, suggesting a nonmnemonic deficit. These results contrast with effects of less selective lesions, which have been taken to support a role for basal forebrain cholinergic neurons in learning and memory.

331 citations

Journal ArticleDOI
TL;DR: Contrary to expectation, selective removal of basal forebrain cholinergic neurons projecting to either hippocampus or neocortex fails to impair learning in a spatial task widely used to study hippocampal/cortical function.
Abstract: The role of the basal forebrain cholinergic system in learning and memory has held considerable interest since the discovery of cholinergic neurodegeneration in the basal forebrain in Alzheimer's disease. Contrary to expectation, selective removal of basal forebrain cholinergic neurons projecting to either hippocampus or neocortex fails to impair learning in a spatial task widely used to study hippocampal/cortical function. If cholinergic neurons contribute to learning and memory by integrated regulation of hippocampal and cortical processing, combined removal of hippocampal and cortical cholinergic projections might be necessary to produce impairment. However, this combined lesion failed to impair spatial learning. These data argue against the view that basal forebrain cholinergic deficiency plays a prominent role in disorders of learning and memory.

125 citations

Journal ArticleDOI
TL;DR: Evidence is provided that a mild to moderate fluid percussion injury produces changes in the cholinergic system in brain areas related to memory.
Abstract: Rats subjected to a mild to moderate fluid percussion injury exhibit memory deficits that are similar to rats that have received lesions of the septohippocampal system. Because the cholinergic system plays a major role in septohippocampal function, we studied the kinetics of the synthetic enzyme for acetylcholine, choline acetyltransferase (ChAT), at 1 h, 24 h, or 5 days after a fluid percussion injury. Decreases in ChAT activity were found in the dorsal hippocampus (25%), frontal (32%), and temporal (23%) cortices 1 h after injury. In the parietal cortex, a greater than 50% increase in ChAT activity was observed at all time intervals assessed. At 5 days after TBI, there was an 18% increase in ChAT activity in the medial septal area. These data provide evidence that a mild to moderate fluid percussion injury produces changes in the cholinergic system in brain areas related to memory.

90 citations


Cited by
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01 Jan 2007
TL;DR: In this article, the authors reveal how smart design is the new competitive frontier, and why some products satisfy customers while others only frustrate them, and how to choose the ones that satisfy customers.
Abstract: Revealing how smart design is the new competitive frontier, this innovative book is a powerful primer on how--and why--some products satisfy customers while others only frustrate them.

7,238 citations

MonographDOI
01 Dec 2014
TL;DR: This chapter discusses the emergence of learning activity as a historical form of human learning and the zone of proximal development as the basic category of expansive research.
Abstract: 1. Introduction 2. The emergence of learning activity as a historical form of human learning 3. The zone of proximal development as the basic category of expansive research 4. The instruments of expansion 5. Toward an expansive methodology 6. Epilogue.

5,768 citations

Journal ArticleDOI
TL;DR: The framework presented in the original article has helped to integrate behavioral, systems, cellular, and molecular approaches to common problems in attention research and has led to increased understanding of aspects of pathology and to some new interventions.
Abstract: Here, we update our 1990 Annual Review of Neuroscience article, “The Attention System of the Human Brain.” The framework presented in the original article has helped to integrate behavioral, systems, cellular, and molecular approaches to common problems in attention research. Our framework has been both elaborated and expanded in subsequent years. Research on orienting and executive functions has supported the addition of new networks of brain regions. Developmental studies have shown important changes in control systems between infancy and childhood. In some cases, evidence has supported the role of specific genetic variations, often in conjunction with experience, that account for some of the individual differences in the efficiency of attentional networks. The findings have led to increased understanding of aspects of pathology and to some new interventions.

2,385 citations

Journal ArticleDOI
TL;DR: Lesions in distinct brain regions like hippocampus, striatum, basal forebrain, cerebellum and cerebral cortex were shown to impair MWM performance, but disconnecting rather than destroying brain regions relevant for spatial learning may impair M WM performance as well.

1,882 citations

Journal Article
TL;DR: In this article, a form of reasoning about a function of consciousness based on the phenomenon of blindsight is presented, where it is shown that some information about stimuli in the blind field is represented in the brains of blind sight patients, as shown by their correct guesses.
Abstract: of the original article: Consciousness is a mongrel concept: there are a number of very different consciousnesses. Phenomenal consciousness is experience; the phenomenally conscious aspect of a state is what it is like to be in that state. The mark of access-consciousness, by contrast, is availability for use in reasoning and rationally guiding speech and action. These concepts are often partly or totally conflated, with bad results. This target article uses as an example a form of reasoning about a function of consciousness based on the phenomenon of blindsight. Some information about stimuli in the blind field is represented in the brains of blindsight patients, as shown by their correct guesses. They cannot harness this information in the service of action, however, and this is said to show that a function of phenomenal consciousness is somehow to enable information represented in the brain to guide action. But stimuli in the blind field are both access-unconscious and phenomenally unconscious. The fallacy is: an obvious function of the machinery of access-consciousness is illicitly transferred to phenomenal consciousness.

1,737 citations