Neurobiology of Social Behavior (eBook)

Toward an Understanding of the Prosocial and Antisocial Brain

Michael Numan (Autor)

eBook Download: PDF | EPUB

2014 | 1. Auflage
358 Seiten
Elsevier Science (Verlag)
978-0-12-391475-0 (ISBN)

Infos

Social neuroscience is a rapidly growing, interdisciplinary field which is devoted to understanding how social behavior is regulated by the brain, and how such behaviors in turn influence brain and biology. Existing volumes either fail to take a neurobiological approach or focus on one particular type of behavior, so the field is ripe for a comprehensive reference which draws cross-behavioral conclusions. This authored work will serve as the market's most comprehensive reference on the neurobiology of social behavior. The volume will offer an introduction to neural systems and genetics/epigenetics, followed by detailed study of a wide range of behaviors - aggression, sex and sexual differentiation, mating, parenting, social attachments, monogamy, empathy, cooperation, and altruism. Research findings on the neural basis of social behavior will be integrated across different levels of analysis, from molecular neurobiology to neural systems/behavioral neuroscience to fMRI imaging data on human social behavior. Chapters will cover research on both normal and abnormal behaviors, as well as developmental aspects. - 2016 PROSE Category winner - Honorable Mention for Biomedicine and Neuroscience - Presents neurobiological analysis of the full spectrum of social behaviors, while other volumes focus on one particular behavior - Integrates and discusses research from different levels of analysis, including molecular/genetic, neural circuits and systems, and fMRI imaging research - Covers both normal and abnormal behaviors - Covers aggression, sex and sexual differentiation, mating, parenting, social attachments, empathy, cooperation, and altruism

Michael Numan received his Ph.D. from the University of Chicago. He is a Fellow of the American Association for the Advancement of Science (AAAS) and the Association for Psychological Science (APS). Most of his research, which focuses on the neural mechanisms regulating maternal behavior, was conducted while he was a Professor of Psychology and Behavioral Neuroscience at Boston College. He is the author of a previous book, with Thomas Insel, The Neurobiology of Parental Behavior. He lives with his wife, Marilyn, in the Santa Fe-Albuquerque region of New Mexico.

Inhalt

Front Cover 1
Neurobiology of Social Behavior: Toward an Understanding of the Prosocial and Antisocial Brain 4
Copyright 5
Dedication 6
Contents 8
Preface 10
About the Author 12
Chapter 1 - An Introduction to Neural Systems 14
1.1 INTRODUCTION 14
1.2 A SCHEMATIC OVERVIEW OF THE MAMMALIAN BRAIN 15
1.3 FUNCTIONAL NEUROANATOMY 16
1.4 CONCLUSIONS 54
Chapter 2 - Basic Genetics and Epigenetics 56
2.1 INTRODUCTION 56
2.2 BASIC GENETICS 56
2.3 BASIC EPIGENETICS 65
2.4 EPIGENETIC EFFECTS ON PHYSIOLOGICAL AND BEHAVIORAL DEVELOPMENT 67
2.5 CONCLUSIONS 74
Chapter 3 - Aggressive Behavior 76
3.1 INTRODUCTION 76
3.2 NEURAL SYSTEMS OF OFFENSIVE AGGRESSION IN NONHUMAN MAMMALS 78
3.3 NEUROBIOLOGY OF IMPULSIVE OR AFFECTIVE AGGRESSION IN HUMANS 99
3.4 EARLY ADVERSE LIFE EXPERIENCES, GENES, AND THE DEVELOPMENT OF AGGRESSION 107
3.5 CONCLUSIONS 118
Chapter 4 - Sexual Behaviors and Sexual Differentiation 122
4.1 INTRODUCTION 122
4.2 THE HORMONAL BASIS OF SEXUAL BEHAVIOR 123
4.3 THE NEUROBIOLOGY OF MALE SEXUAL BEHAVIOR IN NONPRIMATE ANIMALS 124
4.4 THE NEUROBIOLOGY OF FEMALE SEXUAL BEHAVIOR IN NONPRIMATE ANIMALS 136
4.5 THE NEUROBIOLOGY OF SEXUAL BEHAVIOR IN PRIMATES 147
4.6 SEXUAL DIFFERENTIATION AND THE DEVELOPMENT OF SEXUAL BEHAVIOR 156
4.7 CONCLUSIONS 176
Chapter 5 - Parental Behavior 178
5.1 INTRODUCTION 178
5.2 NEURAL SYSTEMS REGULATING MATERNAL MOTIVATION IN RATS 182
5.3 NEURAL SYSTEMS AND MATERNAL BEHAVIOR IN SHEEP: MATERNAL RESPONSIVENESS AND THE FORMATION OF SELECTIVE ATTACHMENTS 216
5.4 MATERNAL BEHAVIOR IN NONHUMAN PRIMATES 220
5.5 PATERNAL AND ALLOPARENTAL BEHAVIOR 222
5.6 DEVELOPMENTAL INFLUENCES ON THE MATERNAL BEHAVIOR OF MAMMALS 227
5.7 THE NEUROBIOLOGY OF MATERNAL BEHAVIOR IN HUMANS 237
5.8 GENERAL CONCLUSIONS 245
Chapter 6 - Monogamy and the Formation of Enduring Social Attachments between Mating Partners 248
6.1 INTRODUCTION 248
6.2 THE VOLE MODEL SYSTEM 249
6.3 OT AND VASOPRESSIN NEURAL SYSTEMS AND THE REGULATION OF SOCIAL MONOGAMY IN BIRDS AND PRIMATES 270
6.4 OT, VASOPRESSIN, AND PAIR BONDING: CONCLUSIONS 275
6.5 THE RELATIONSHIP OF OT NEURAL SYSTEMS TO AUTISM SPECTRUM DISORDER 276
Chapter 7 - Human Sociality 284
7.1 INTRODUCTION 284
7.2 AN EVOLUTIONARY PERSPECTIVE 284
7.3 IMPORTANT POINTS FROM PREVIOUS CHAPTERS 287
7.4 THE INSULAR CORTEX AND EMPATHY: A POTENTIAL STARTING POINT THROUGH WHICH FEELING STATES INFLUENCE PROSOCIAL BEHAVIORS 289
7.5 OXYTOCIN AND HUMAN PROSOCIALITY 297
7.6 HUMAN PROSOCIALITY: CONCLUSIONS 302
7.7 PSYCHOPATHY: A BREAKDOWN OF PROSOCIAL NEURAL CIRCUITS THAT RESULTS IN ANTISOCIAL BEHAVIOR 303
7.8 EPILOGUE 311
References 314
Index 354

Textauszug

Chapter 2

Basic Genetics and Epigenetics

Abstract

Since genes control the synthesis of proteins, variations in the structure and function of neuron-related genes can influence the operation of the nervous system and social behavior. The gene is divided into a regulatory and a coding region, and the role of transcription factor action within the regulatory region in the control of gene expression is described. Genetic polymorphisms cause variations in the nucleotides within a gene, leading to different alleles of a gene, which could affect the amount of gene-related protein synthesized. Epigenetic processes influence whether a gene is in a euchromatin open and transcribable state, or a heterochromatin closed state. Histone acetylation and DNA methylation influence these processes. Postnatal experiences can affect whether neuron-related genes are euchromatin or heterochromatin. For example, maternal care influences the subsequent stress reactivity of offspring, with one mediating mechanism involving epigenetic effects on the transcribability of the glucocorticoid receptor gene.

Keywords

DNA; Epigenetics; Gene–environment interaction; Gene transcription; Knockout mutation; mRNA; mRNA translation; Repetitive sequence polymorhism; Single nucleotide polymorphism; Stress reactivity

2.1. Introduction

This chapter provides an introduction to the role of genes in neuron function and behavior. Genetic and environmental factors both influence behavior, including social behaviors, and these two factors often interact to mold the way in which brain and behavior develop. I will present the fundamentals of molecular biology, followed by concrete examples of how genes and environmental factors act together to affect developmental processes. These concepts will be important for a full understanding of the gene–social behavior relationships developed in future chapters.

Genes are composed of deoxyribonucleic acid (DNA) and are located within the chromosomes of a cell’s nucleus. Figure 2.1 explains the terms replication, transcription, and translation. During meiosis and mitosis, the DNA in a particular cell is capable of replicating itself in order to be incorporated into newly formed cells. For example, during mitotic divisions, new cells are produced that contain the same DNA as the parent cell. During meiosis, a mature gamete (sperm or ova) acquires one member of each pair of chromosomes from a diploid germ cell. DNA replication provides the mechanism for genetic heredity, as copies of DNA are transferred to newly produced cells, which include gametes. But the term heredity cannot be fully appreciated without an understanding of what genes do. In each cell in our body, genes control the synthesis of ribonucleic acid (RNA), and this process is referred to as transcription. Several kinds of RNA exist, including messenger RNA (mRNA), ribosomal RNA, and transfer RNA (tRNA). My main concern will be mRNA, the form of RNA that contains the code that regulates protein synthesis. The process through which mRNA forms a template that controls the sequence of amino acids that make up a particular protein is referred to as translation. Therefore, with respect to protein synthesis, the following general sequence of events occurs: gene X (DNAx; a gene located at a particular locus on a particular chromosome) controls the synthesis of mRNAx, which, in turn, controls the synthesis of protein X. Similarly, gene Y (DNAy) would control the synthesis of protein Y, using mRNAy as an intermediary. Since the types of proteins synthesized in a cell influence the structure and function of the cell, one can see how genes regulate the structure and function of all cells, including neurons.

2.2. Basic Genetics

2.2.1. The Structure of Nucleotides

Several sources have provided the information in this section, and the reader is referred to these for a more comprehensive review of basic genetic mechanisms: Alberts et al. [15]; Champe, Harvey, and Ferrier [175]; Hyman and Nestler [438]; Lewin [550]; Matthews, Freedland, and Miesfeld [613].

FIGURE 2.1 General depiction of the replication, transcription, and translation processes with respect to two separate genes, referred to as Gene X (DNA X in red) and Gene Y (DNA Y in red). Genes can replicate themselves during mitosis and meiosis (DNA-to-DNA). The transcription (DNA-to-mRNA) and translation (mRNA-to-protein) processes allow particular genes to regulate the synthesis of particular proteins.

A single strand of DNA or RNA is composed of a sequence of nucleotides that are linked together by strong covalent bonds. A single nucleotide contains a nitrogenous base, a pentose (5 carbon) sugar, and a phosphate group. The strong covalent bond that links two nucleotides together within a stand of DNA or RNA occurs between the phosphate group (PO4 = P) attached to the 5-carbon position on the sugar of one nucleotide (referred to as the 5? position) and the hydroxyl (OH) group located at the 3-carbon position (referred to as the 3? position) on the sugar of the next nucleotide in the sequence. This relationship is schematically illustrated in Figure 2.2(A). Notice how one end of the nucleotide sequence, referred to as the 5? end, contains a free phosphate group, while the other end, referred to as the 3? end, contains a free hydroxyl group. The different bases that are present in DNA include thymine (T), adenine (A), guanine (G), and cytosine (C). These same bases are present in RNA, except that uracil (U) is used in place of thymine. The pentose in DNA is deoxyribose, while that in RNA is ribose. A nucleotide sequence can be conceived as a series of bases protruding from a sugar–phosphate backbone, and a particular sequence might be written as 5?-pApTpTpG-3?.

FIGURE 2.2 The general chemical structure of RNA and DNA. (A) RNA is composed of a single strand of nucleotides. Each nucleotide contains a pentose sugar (S = ribose), a base (B), which can be uracil, adenine, guanine, or cytosine, and a phosphate group (P). Nucleotides are linked together by covalent bonds between the phosphate group located at the 5?-carbon position on the sugar molecule of one nucleotide and the hydroxyl group (OH) located at the 3?-carbon position of the adjoining sugar molecule. The linkages that are formed are referred to as the sugar–phosphate backbone of the nucleotide sequence. O = oxygen. (B) DNA is composed of a double strand of nucleotides. The pentose sugar (S) is deoxyribose, and DNA contains the same bases as RNA, except that thymine is used instead of uracil. The two nucleotide strands within DNA are linked together by hydrogen bonds (dashed lines) between complementary bases. Guanine (G) is complementary to cytosine (C), and thymine (T) is complementary to adenine (A). Compared to part (A), the sugar–phosphate backbone has been simplified, and deoxyribose had been drawn as a circle, although in reality its structure is similar to ribose (both are pentose sugars).

While RNA is composed of a single strand of nucleotides, DNA contains two separate intertwining strands of nucleotides (forming a double helix), with the bases in one strand linked to the bases in the other strand by relatively weak hydrogen bonds (in comparison to the strong covalent bonds between the sugars in each separate strand). Double-stranded DNA is schematically shown in Figure 2.2(B). Note that particular bases are complementary to one another, which allows them to form hydrogen bonds: G is complementary to C, and A is complementary to T (A is also complementary to U, which is important for transcription, as will be described below). When viewing the two strands of nucleotides that compose DNA, note that one strand runs in the 5?-to-3? direction, while its complementary strand runs in the 3?-to-5? direction.

2.2.2. General Transcription and Translation Processes

During transcription, single-stranded RNA is synthesized from double-stranded DNA within the nucleus of a cell. In order for transcription to occur, the enzyme RNA polymerase must attach and bind to DNA. The DNA strands then unwind, and RNA polymerase moves along the strand that is referred to as the template strand in the 3?-to-5? direction in order to catalyze the synthesis of an RNA strand that is organized in the 5?-to-3? direction and is composed of bases that are complementary to those of the DNA template strand. This general process is shown in Figure 2.3(A). Because of this process, the base sequence in the synthesized RNA strand matches that of the 5?-to-3? DNA strand, except that uracil replaces thymine. Since the nontemplate DNA strand matches the base sequence of the synthesized RNA, it is called the coding strand or the sense strand. By convention, when one refers to the nucleotide sequence of DNA that codes for a particular RNA, one uses the sequence shown by the 5?-to-3? coding strand.

With respect to protein synthesis and translation, once a “mature” mRNA is synthesized within the nucleus of a cell, it leaves the nucleus and moves to the ribosomes within the cytoplasm. Triplet nucleotide sequences within mRNA, referred to as codons, code for particular amino acids. At the ribosomes, mRNA provides the information needed to link together the specific amino acids that compose a particular protein or peptide. As shown in Figure 2.3(A), the...

Produkt-Details

• Erscheint lt. Verlag: 17.7.2014
• Sprache: englisch
• Themenwelt: Geisteswissenschaften ► Psychologie ► Biopsychologie / Neurowissenschaften
• Themenwelt: Geisteswissenschaften ► Psychologie ► Familien- / Systemische Therapie
• Themenwelt: Geisteswissenschaften ► Psychologie ► Sozialpsychologie
• Themenwelt: Medizin / Pharmazie
• ISBN-10: 0-12-391475-2 / 0123914752
• ISBN-13: 978-0-12-391475-0 / 9780123914750