Behavioral Neuroscience Vocab 1.1, 1.4, 2.1

neuron

the basic unit of the nervous system, each composed of a cell body, receptive extension(s) (dendrites), and a transmitting extension (axon)

synapse

a point where a neuron contacts many other cells

axon

a specialized extension of neurons that is microscopically slender, yet may be several feet long

biological psychology

the field that relates behavior to bodily processes

neuroscience

the study of the nervous system

behavioral neuroscience

the study of the neural bases of behavior and mental processes; also called biological psychology

ontogeny

the process by which an individual changes in the course of its lifetime—that is, grows up and grows old

conserved

in the context of evolution, referring to a trait that is passed on from a common ancestor to two or more descendant species

dualism

within the concept of separation of soul and body, the motion promoted by Rene Descartes that the mind is subject only to spiritual interactions while the body is subject only to material interactions

phrenology

the disproved theory that bumps on the skull reflect enlargements of brain regions responsible for certain behavioral faculties

consciousness

the state of awareness of one’s own existence and experience

cell assemblies

describes how brain cells that are initially connected in a somewhat random fashion can become organized into circuits as a consequence of activation

Hebbian synapse

describes how synaptic connections can become strengthened through use

glial cells

nonneuronal brain cells that provide structural, nutritional, and other types of support to the brain

histology

the scientific study of the composition of tissues

Nissl stain

a cell stain that reveals all cell bodies by staining RNA

Golgi stain

a cell stain that fills a small proportion of neurons with a dense dark product

autoradiography

a histological technique that shows the distribution of radioactive chemicals in tissues

immunohistochemistry (IHC)

a technique in which labeled antibodies are used to visualize the histological distribution of specific proteins

c-fos

an immediate early gene (IEG) that is expressed in cells that have been recently active

in situ hybridization

a method for detecting particular RNA transcripts in tissue sections by providing a nucleotide probe that is complementary to, and will therefore hybridize with, the transcript of interest

tract tracer

a compound used to identify the routes and interconnections of neuronal projections

anterograde labeling

the tract tracer is injected near the dendrites and cell bodies of a region of interest, where it is taken up and transported to the tips of the axons, thus revealing the targets of the neurons in the region under study

retrograde labeling

when a different kind of tract tracer is injected into a region of interest, it is taken up by axon terminals and then transported back to their originating cell bodies, thus revealing the sources of innervation of the region

transsynaptically

tract tracers that jump backward across synapses and work their way “upstream,” back toward higher levels of the nervous system, leaving visible molecules of label all along the way

neuron doctrine

the hypothesis that the brain is composed of cells that are distinct structurally, metabolically, and functionally and information is transmitted from one neuron to the next across tiny gaps

synapse

the tiny gap between neurons where information is passed from one to the other

cell body

the region of a neuron that is defined by the presence of the cell nucleus; also called soma

mitochondrion

a cellular organelle that provides metabolic energy for the cell’s processes

cell nucleus

the spherical central structure of a cell that contains the chromosomes

ribosomes

structures in the cell body where genetic information is translated to produce proteins

input zone

the part of a neuron that receives information from other neurons or from specialized sensory structures; usually corresponds to the cell’s dendrites

dendrite

one of the extensions of the cell body through which synaptic inputs are received

integration zone

the part of the neuron that initiates nerve electrical activity; it usually corresponds to the neuron’s axon hillock

conduction zone

the part of the neuron over which the nerve’s electrical signal may be actively propagated; it usually corresponds to the cell’s axon

axon

a single extension from the nerve cell that carries action potentials from the cell body to other neurons

axon collateral

a branch of an axon from a single neuron

output zone

the part of a neuron, usually corresponding to the axon terminals, at which the cell sends information to another cell

axon terminal

the end of an axon or axon collateral, which forms a synapse on a neuron or other target cell; also called synaptic bouton

multipolar neuron

a nerve cell that has many dendrites and a single axon

bipolar neuron

a nerve cell that has a single dendrite at one end and a single axon at the other end

unipolar neuron

a nerve cell with a single branch that leaves the cell body and then extends in two directions; one end is the receptive pole, the other end the output zone

interneuron

a neuron that is neither a sensory neuron nor a motor neuron; it receives input from and sends outputs to other neurons

motor neuron

a nerve cell in the brain or spinal cord that transmits motor messages, stimulating a muscle or gland

sensory neuron

a neuron that is directly affected by changes in the environment, such as light, odor, or touch

arborization

the elaborate branching of the dendrites of some neurons

presynaptic

referring to the region of a synapse that releases neurotransmitters

postsynaptic

referring to the region of a synapse that receives and responds to neurotransmitters

presynaptic membrane

the specialized membrane of the axon terminal of the neuron that transmits information by releasing neurotransmitters

synaptic cleft

the space between the presynaptic and postsynaptic membranes

postsynaptic membrane

the specialized membrane on the surface of the cell that receives information by responding to neurotransmitters from a presynaptic neuron

synaptic vesicle

a small, spherical structure that contains molecules of neurotransmitter

neurotransmitter

the chemical released from the presynaptic axon terminal that serves as the basis of communication between neurons

receptor

a protein that binds and reacts to molecules of a neurotransmitter or hormone

neural plasticity

the ability of the nervous system to change in response to experience or the environment

axon hillock

a cone-shaped area from which the axon originates out of the cell body; functionally, it is the integration zone of the neuron

innervate

to provide neural input

motor protein

a specialized kinetic protein molecule that conveys a load, such as a vesicle, from one location to another within a cell

axonal transport

the transportation of materials between the neuronal cell body and axon terminals

anterograde transport

a type of axonal transport that moves material toward the axon terminals

retrograde transport

a type of axonal transport that moves used materials back to the cell body for recycling

astrocyte

a star-shaped glial cell with numerous processes (extensions) that run in all directions

microglial cells

extremely small glial cells that remove cellular debris from injured or dead cells

oligodendrocyte

a type of glial cell that forms myelin in the central nervous system

Schwann cell

a glial cell that forms myelin in the peripheral nervous system

myelination

the process of ensheathing axons in myelin

myelin

the fatty insulation around an axon, formed by glial cells, that speeds the conduction of axon potentials

node of Ranvier

a gap between successive segments of the myelin sheath where the axon membrane is exposed

edema

the swelling of tissue, such as in the brain, in response to injury

multiple sclerosis

literally, “many scars;” a disorder characterized by widespread degeneration of myelin