Book contents
- Frontmatter
- Dedication
- Contents
- List of contributors
- Editor's preface
- PART I INTRODUCTION AND GENERAL PRINCIPLES
- PART II DISORDERS OF HIGHER FUNCTION
- 13 Congenital disorders of cerebral cortical development
- 14 The aging brain: morphology, imaging and function
- 15 Neurodegenerative diseases
- 16 Aging and dementia: principles, evaluation and diagnosis
- 17 Alzheimer's Disease
- 18 Dementia with Lewy bodies
- 19 Frontotemporal dementia
- 20 Consciousness and its disorders
- 21 Mechanisms of memory and amnestic syndromes
- 22 Acquired disorders of language
- 23 Neglect
- 24 Brain death
- 25 Disorders of mood
- 26 Schizophrenia
- 27 Obsessive–compulsive disorder
- 28 Autism and autistic spectrum disorders
- 29 Attention deficit hyperactivity disorder: spectrum and mechanisms
- 30 The neurobiology of drug addition
- PART III DISORDERS OF MOTOR CONTROL
- PART IV DISORDERS OF THE SPECIAL SENSES
- PART V DISORDERS OF SPINE AND SPINAL CORD
- PART VI DISORDERS OF BODY FUNCTION
- PART VII HEADACHE AND PAIN
- PART VIII NEUROMUSCULAR DISORDERS
- PART IX EPILEPSY
- PART X CEREBROVASCULAR DISORDERS
- PART XI NEOPLASTIC DISORDERS
- PART XII AUTOIMMUNE DISORDERS
- PART XIII DISORDERS OF MYELIN
- PART XIV INFECTIONS
- PART XV TRAUMA AND TOXIC DISORDERS
- PART XVI DEGENERATIVE DISORDERS
- PART XVII NEUROLOGICAL MANIFESTATIONS OF SYSTEMIC CONDITIONS
- Complete two-volume index
- Plate Section
21 - Mechanisms of memory and amnestic syndromes
from PART II - DISORDERS OF HIGHER FUNCTION
Published online by Cambridge University Press: 05 August 2016
- Frontmatter
- Dedication
- Contents
- List of contributors
- Editor's preface
- PART I INTRODUCTION AND GENERAL PRINCIPLES
- PART II DISORDERS OF HIGHER FUNCTION
- 13 Congenital disorders of cerebral cortical development
- 14 The aging brain: morphology, imaging and function
- 15 Neurodegenerative diseases
- 16 Aging and dementia: principles, evaluation and diagnosis
- 17 Alzheimer's Disease
- 18 Dementia with Lewy bodies
- 19 Frontotemporal dementia
- 20 Consciousness and its disorders
- 21 Mechanisms of memory and amnestic syndromes
- 22 Acquired disorders of language
- 23 Neglect
- 24 Brain death
- 25 Disorders of mood
- 26 Schizophrenia
- 27 Obsessive–compulsive disorder
- 28 Autism and autistic spectrum disorders
- 29 Attention deficit hyperactivity disorder: spectrum and mechanisms
- 30 The neurobiology of drug addition
- PART III DISORDERS OF MOTOR CONTROL
- PART IV DISORDERS OF THE SPECIAL SENSES
- PART V DISORDERS OF SPINE AND SPINAL CORD
- PART VI DISORDERS OF BODY FUNCTION
- PART VII HEADACHE AND PAIN
- PART VIII NEUROMUSCULAR DISORDERS
- PART IX EPILEPSY
- PART X CEREBROVASCULAR DISORDERS
- PART XI NEOPLASTIC DISORDERS
- PART XII AUTOIMMUNE DISORDERS
- PART XIII DISORDERS OF MYELIN
- PART XIV INFECTIONS
- PART XV TRAUMA AND TOXIC DISORDERS
- PART XVI DEGENERATIVE DISORDERS
- PART XVII NEUROLOGICAL MANIFESTATIONS OF SYSTEMIC CONDITIONS
- Complete two-volume index
- Plate Section
Summary
Memory comprises the recording, retention and retrieval of knowledge. All that we know, except for what is genetically predetermined, is acquired through experience. Such knowledge includes the events we remember, the facts we know, and the skills we master. Memory is not a unitary faculty, but rather an ensemble of multiple forms of learning that differ in their uses, their operating characteristics, and the neural networks that mediate their processing (Gabrieli, 1998). A memory system may be defined as a particular neural network that mediates a specific form of mnemonic processing. Neurological and psychiatric diseases result in characteristic mnemonic deficits that reflect which memory systems are injured by a particular disease.
Levels of analysis: cells and systems
Learning and memory reflect experience-induced plasticity in the brain. An experience leaves a memory trace composed of an enduring alteration in the cellular organization of the brain called an engram. Experience-induced plasticity can be examined at many levels of analysis, including molecular events at the cellular and synaptic level, reorganization of local neuronal circuits, and large-scale alterations in the functional neural architecture of memory systems.
Cellular mechanisms of memory
Little is known about neural plasticity in the human brain, but findings from in vitro and invertebrate models offer suggestions about the cellular bases of human memory. Studies of the marine snail Aplysia have revealed links between learning and alterations in neurotransmitter release. Aplysia have a gill withdrawal reflex that is triggered when the gill is touched by a rod. Repeated stimulation leads to habituation such that the gills are no longer withdrawn in response to the rod. Short-term habituation has been linked to decreased presynaptic transmitter release. Repeated stimulation with a highly noxious stimulus, such as an electric shock, can lead to sensitization, an intensification of the withdrawal response. Short-term sensitization involves increased neurotransmitter release from a facilitating interneuron (Kandel & Schwartz, 1982). Modulation of neurotransmitter release may underlie short-term changes in functional connectivity between neurons.
Long-term memory processes, in contrast, require messenger RNA and protein synthesis (Davis & Squire, 1984) to establish structural changes in synaptic connectivity as a record of experience.
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- Diseases of the Nervous SystemClinical Neuroscience and Therapeutic Principles, pp. 301 - 316Publisher: Cambridge University PressPrint publication year: 2002