The development of the young brain after birth and the emergence of cognitive capacities, mind, and individuality rest on the maturation of a dense net of synaptic connections between neurons. Memory Makes the Brain describes the dramatic, competitive elimination of surplus synapses that occur in the young, maturing brain in a process called synaptic pruning that was discovered by pediatric neurologist Peter Huttenlocher in the 1970's at the University of Chicago. Explaining similarities between developmental pruning and learning processes in the adult brain, neurobiologist Christian Hansel offers a unique perspective on brain adaptation and plasticity throughout lifetime, at times weaving in personal accounts and memories. The cellular plasticity machinery that enables learning is known to be affected in brain developmental disorders such as autism. Memory Makes the Brain explains how both maturation and adult synaptic plasticity are deregulated in autism, and how we begin to trace back autism-typical behavioral abnormalities to such synaptopathies.
Author(s): Christian Hansel
Publisher: World Scientific Publishing
Year: 2021
Language: English
Pages: 192
City: Singapore
Contents
Acknowledgments
Introduction
1. Peter Huttenlocher and the Discovery of Synaptic Pruning
References
2. Why Postnatal Brain Plasticity Is Needed: Limitations of Genetic Blueprints
References
3. What Goes Up Must Come Down: Synaptic Potentiation and Depression
Calcium Influx as a Trigger Signal for Long-term Potentiation (and Depression)
Downstream of Calcium Transients: Biochemical Pathways Regulating AMPA Receptor Trafficking
References
4. Across Time: Shared Synaptic Plasticity Machinery in the Developing and the Adult Brain
Pruning in the Visual Cortex Following Molecular Deprivation
The Molecular Machinery of Synaptic Depression at a Cerebellar Synapse
Climbing Fiber Pruning in the Developing Cerebellum
Synapse Elimination and LTD at the NMJ
Temporal Continuity Between LTD-like Depression and Synapse Elimination
Termination of the Critical Period
A Role in Autism
References
5. Synaptopathies: Synaptic Dysfunction in Autism
Genetic and Environmental Factors Contribute to Autism
Cell Physiological Signatures of the Autistic Brain
Autism Phenotypes that may Result from LTD Deregulation
References
6. The Study of Autism-Resembling Behaviors in Mouse Models
Modeling Human Behaviors in Laboratory Animals
Three-chamber Test for Social Approach
Ultrasonic Vocalization in Mice
Repetitive Behaviors: Marble Burying and Self-grooming
Anxiety: Tests for the Occupation of Open Versus Protected Spaces
Nociception: Hot Plate Test and Tail Flick Test
Motor Performance and Motor Learning
The Importance of Access to Underlying Brain Circuits
Animal Models Other than Mice
Autism from a Synaptic Perspective
References
7. The Memory Engram
References
8. Limitations: The Non-Synaptic Plasticity Component
References
9. Ensemble Sequences, Associative Plasticity and the Learning of Causal Relationships
Intrinsic Plasticity and Learned Feature Generalization
Effect Robustness and Duration
Synaptic and Intrinsic Mechanisms Control the Probability of Engram Activation and Engram Sequences
Intrinsic Contributions
Synaptic Contributions
Language Impairment and Cerebellar Dysfunction in Autism
References
10. Plasticity and the Shaping of Individual Brains
Plasticity, Circuit Learning and the Origin of Individuality
Individuality and Self-awareness Arising from Experience
References
Index
