Ch.1 An Invitation to Neurobiology

Question 1

Nature

Answer 1

The contribution of genetic inheritance to brain function and behavior

Question 2

Nurture

Answer 2

The contribution of environmental factors to brain function and behavior

Question 3

Monozygotic (identical) twins

Answer 3

Twins produced from the same fertilized egg or zygote, they share 100% of their genomes

Question 4

Dizygotic twins

Answer 4

Non-identical (fraternal) twins who share only 50% of their genes, because they originated from two independent eggs fertilized by two independent sperm

Question 5

Heritability

Answer 5

A measure of the contribution of genetic differences to to trait differences within a population

Question 6

Epigenetic modifications

Answer 6

Molecular modifications to DNA and chromatin, such as DNA methylation and various forms of post-translational modifications of histones. They do not modify the DNA sequence but can alter gene expression

Question 7

Innate

Answer 7

A trait or behavior that is genetically programmed and that is thus with an organism from birth rather than acquired by experience

Question 8

Stereotypy

Answer 8

A trait or behavior that is largely invariant in different individual organisms

Question 9

Neuroethology

Answer 9

A branch of science that emphasizes the study of animal behavior in the natural environment

Question 10

Fixed action pattern

Answer 10

An instinctive sequence of behaviors, it is largely invariant and runs to completion once triggered

Question 11

Releasers

Answer 11

The essential features of a stimulus that activate a fixed action pattern

Question 12

Neural plasticity

Answer 12

Changes of the nervous system in response to experience and learning

Question 13

Central Nervous System (CNS)

Answer 13

The brain and spinal cord in vertebrates; the brain and nerve cord in some invertebrates

Question 14

Brain

Answer 14

The rostral part of the CNS located in the head. It is the command center for nervous system functions

Question 15

Spinal Cord

Answer 15

The caudal part of the vertebrate CNS enclosed by the vertebral column

Question 16

Hemispheres

Answer 16

The two sides of the brain

Question 17

Cerebral Cortex

Answer 17

The outer layer of the neural tissue in the rostral part of the mammalian brain. It is associated with higher functions including sensory perception, cognition, and control of voluntary movement

Question 18

Basal Ganglia

Answer 18

A collection of nuclei underneath the cerebral cortex, it includes the straitum, globus pallidus, subthalmic nucleus, and substantia nigra and is essential for motor initiation and control, habit formation, and reward-based learning

Question 19

Hippocampus

Answer 19

A structure underneath the cortical surface of the temporal lobe. It has been most studied for its role in the acquisition of explicit memory and representation of space

Question 20

Amygdala

Answer 20

An almond-shaped structure underneath the temporal lobe best known for its role in processing emotion-related information

Question 21

Thalamus

Answer 21

A structure situated between the cerebral cortex and the midbrain, it relays sensory and motor signals to the cerebral cortex through its extensive bidirectional connections with cortex

Question 22

Hypothalamus

Answer 22

A collection of nuclei ventral to the thalamus, it controls many bodily functions including eating, digesting, metabolic rate, drinking, salt intake, reproduction, body temperature, emergency response, and circadian rhythms. It executes many of these functions by regulating the autonomic nervous system and neuroendocrine system

Question 23

Cerebellum

Answer 23

A structure located dorsal to the pons and medulla, it plays an important role in motor coordination, motor learning, and cognitive functions

Question 24

Midbrain

Answer 24

The rostral-most part of the brainstem, it includes the tectum (superior and inferior colliculus in mammals) dorsally and the tegmentum ventrally. Ot is also the middle part of the three divisions of the embryonic brain caudal to the forebrain and rostral to the hindbrain. It is also called the mesencephalon

Question 25

Pons

Answer 25

The middle part of the brainstem caudal to the midbrain and rostral to the medulla

Question 26

Medulla

Answer 26

The caudal-most part of the brainstem between the pons and the spinal cord

Question 27

Forebrain

Answer 27

The rostral-most division of the three divisions of the embryonic brain. It gives rise to the cerebral cortex, basal ganglia, hippocampus, amygdala, thalamus, and hypothalamus

Question 28

Hindbrain

Answer 28

The caudal-most division of the three divisions of the embryonic brain. It gives rise to the pons, medulla, and cerebellum

Question 29

Nerve

Answer 29

A discrete bundle of axons in the peripheral nervous system

Question 30

Ganglia

Answer 30

A cluster of neurons located in the peripheral nervous system

Question 31

Coronal section

Answer 31

A section plane that is perpendicular to the rostral-caudal axis; also called frontal or transverse sections

Question 32

Sagittal section

Answer 32

A section plane that is perpendicular to the medial-lateral axis

Question 33

Medial-lateral

Answer 33

Of a body axis, from midline to side

Question 34

Horizontal sections

Answer 34

A section plane that is perpendicular to the dorsal-ventral axis

Question 35

Dorsal-ventral

Answer 35

Of a body axis, from back to belly

Question 36

Neuraxis

Answer 36

Axis of the CNS. The rostral-caudal neuraxis follows the curvature of the embryonic neural tube; the dorsal-ventral neuraxis is perpendicular to the rostral-caudal neuraxis

Question 37

Neural tube

Answer 37

A hollow tube surrounded by layers of neuroectodermal cells, it is the embryonic precursor to the vertabrate CNS

Question 38

Glia

Answer 38

Nonneuronal cells of the nervous system, they play essential roles for the development and function of neurons

Question 39

Neuronal process

Answer 39

Cytoplasmic extension of a neuron

Question 40

Axon

Answer 40

A long, thin process of a neuron, it often extends far beyond the soma and propagates and transmits signals to other neurons or muscle at its presynaptic terminals

Question 41

Soma

Answer 41

Cell body of a neuron or any cell

Question 42

Dendrites

Answer 42

Thick, bushy processes of a neuron that receive and integrate synaptic inputs from other neurons

Question 43

Presynaptic terminal

Answer 43

A structure at the end (or along the trunk) of an axon that is specialized for releasing neurotransmitters onto target cells

Question 44

Dendritic spine

Answer 44

A small protrusion on a dendrite of certain neurons that receives synaptic input from a partner neuron. The thin spine neck creates chemical and electrical compartments for each spine such that it can be modulated independently from neighboring spines

Question 45

Oligodendrocyte

Answer 45

A glial cell in the CNS that wraps axons with its cytoplasmic extension to form myelin sheath

Question 46

Schwann cell

Answer 46

A glial cell in the PNS that wraps axons with its cytoplasmic extension to form myelin sheath

Question 47

Astrocyte

Answer 47

A glial cell present in the gray matter. It plays many roles including synaptic development and function

Question 48

Microglia

Answer 48

A glial cell that functions as the resident immune cell of the nervous system. It engulfs damaged cells and debris

Question 49

Myelin sheath

Answer 49

Cytoplasmic extensions of oligodendrocytes and Schwann cells, they wrap around axons with multi-layered glial plasma membrane to increase resistance and decrease capacitance for action potential propagation

Question 50

White matter

Answer 50

The parts of the CNS that are enriched with oligodendrocytes and myelinated axons and that appear white because of the high lipid content of the myelin

Question 51

Gray matter

Answer 51

The parts of the CNS that are enriched with neuronal cell bodies, dendrites, axon terminals, and synapses and that appear gray

Question 52

Cell theory

Answer 52

The idea that all living organisms are composed of cells as basic units

Question 53

Reticular theory

Answer 53

The idea that the processes of nerve cells fuse and form a giant net that constitutes the working unit of the nervous system. It has been mostly disproven (with the exception of electrical synapses, that allow limited exchange of ions and small molecules between partner neurons)

Question 54

Golgi staining

Answer 54

A histological staining method, it uses solutions of silver nitrate and potassium dichromate, which react to form a black precipitate (microcrystals of silver chromate). This precipitate accumulates stochastically in a small fraction of the nerve cells so that these cells, and most or all of their elaborate extensions, can be visualized against unstained tissue