Fundamental of Neuro Test 1 deck

Monozygotic (identical) twins

Which type of people are good for nature vs. nurture studies

Environmental factors

Factors that aren’t inherited directly from parent’s DNA, including

Heritability

Contribution of genetic differences to trait differences

Epigenetic modifications

Changes made to DNA chromatin that doesn’t modify DNA gene sequences but alters expression. (DNA methylation, histone modification, ect.)

Innate Behavior

Behavior from birth that is likely genetically programmed

Can

Heritability ____ be altered by environment

Stereotypic behavior

Different members of the same species have the same behavior with similar stimulus specificity

Behavior runs to completion without further sensory information

Neuroethology

Emphasizes observing animals in natural environment

Says instinctive behaviors are following fixed action patterns

Neuroplasticity

Changes in nervous system in response to experiences and learning

Central nervous system (CNS) and peripheral nervous system (PNS)

What are the 2 parts of the nervous system for all vertebrates and most invertebrates?

Brain and spinal cord

What are the parts of the central nervous system

Frontal lobe, parietal lobe, temporal lobe, cerebellum, and occipital lobe

What are the lobes of the brain

Cervical, thoracic, lumbar, and sacral

What are the segments of the spinal cord

Bilaterally

Brain and spinal cord are ______ symmetric

Rostral caudal/ anterior posterior axis

Goes from head or top to tail or bottom

Dorsal ventral axis

Goes from the back of an animal to the belly

Medial-lateral axis

From the bilateral midline of the animal either way out left or right

Sagittal plane

Perpendicular to medial lateral axis, cuts along midline so would have 2 bilaterally semetric pieces

Horizontal axis

Perpendicular to dorsal-ventral axis, would cut in half separating front and back side

Transverse/cross section

Perpendicular anterior posterior/ rostral caudal axis, would separate head part from legs

Peripheral nervous system

Nerves that connect CNS with internal organs and ganglia outside spinal cord

Nerves

Discrete bundles of axons

Ganglia

Clusters of cell bodies of nerve cells

Neuraxis

Curvature of embrionicneural tube that vertebrate nervous system is from

Sulci

Groves in the brain

Gyri

The raised areas in the brain compared to the grooves

Neurons and glia

What are the 2 different types of cells that the nervous system is made of

Neurons

Nerve cells

Dendrites and axons

What are the 2 different cytoplasmic extensions or neuronal processes in the neuron

Axon

Long thin process (cytoplasmic extension) that goes way beyond soma and transmits information

Dendrites

Thick bushy processes (cytoplasmic extensions) that are closer to the cell body and recieve information

Pre-synaptic terminals

At the ends of actions and are specialize structures that help transfer information extracellularly between neurons

Dendritic spines

Small protrusions in many vertebrate dendrites that transfer intracellular information

Glia

Anything in the nervous system that is not a neuron

Oligodendrocytes, schwann cells, astrocytes, microglia

What are the 4 types of Glia

Oligodendrocytes

Wrap around axons in CNS with cytoplasmic extensions making myelin sheath

White matter

From oligodendrocytes and mylineated matter being rich in white lipids and has a lot of axons

Schwann cells

Use cytoplasmic extensions to wrap axons in PNS making myelin sheath

Astrocytes

Many roles in neuronal development and neuronal communication regulation in grey matter of CNS

Grey matter

Has many neuronal cell bodies, dendrites, axon terminals, and connections between neurons with less lipid-rich mylineated matter and oligodendrocytes

Mircoglia

Immune cells of nervous system and englulf damaged cells and debris and help reorganize neuronal connections during development and in response to experience.

Cell Theory

By Schleiden and Schwann and stated that all living organisms were made of cells as basic unit

Reticular Theory

Championed by Golgi

Stated nerve cells linked and formed giant net (recticulum) which was the basic unit of nervous system

Golgi Stain

Neural tissue was soaked in silver nitrate and potassium dichromate to make nervous system more visible.

Allowed visualization of entire morphology of individual neurons for the 1st time

Supported belief that recticulum was basic unit because appeared like giant net

Neuron Doctrine

Ramon y Cajal

Stated neurons connect with each other and communicated at connected sites

Proved neurons were independent units of nervous system

Supported by observing axon growth in vitro because neurons started as cell bodies and grew out guided by growth cone

Later supported by electron microscopy showing synaptic cleft at nanometer level

Synapse

Named by Sherrington

Describes site where neurons were connected

Growth cone

Structure that guides axon to final destination, changing shape as axon extends

Synaptic clef

20-100 nm gap between neuron and the target

Synaptic vesicles

In presynaptic neurons and are filled with neurotransmitters which are released when fuses with plasma membrane upon stimulation

Postsynaptic specializations/ post synaptic destinies

In postsynaptic target cells and are enriched in neurotransmitter receptors

Chemical synapses

What is the predominant way that neurons communicate with each other

Electrical synapses

Other way neurons communicate with each other, but are less prominent and mediated by gap junctions

Gap junction channels

Protein subunits that link cytoplasm of 2 adjacent neurons that only small molecules can travel between

Dendritic morphologies and axonal projections

What are the specific patterns that are used for the classification of neurons

Pyramidal neuron

Pyramid shaped cell body with apical dendrite and several basal dendrites

Most common in mammal’s cerebral cortex and hippocampus

A lot of dendritic spines sprout so postsynaptic specializations are close to presynaptic specializations

Basket cells

Axon terminals are wrapped around cell bodies in pyramidal cells in cerebral cortex and purkinje cells in cerebellum

Spinal cord motor neuron

Extends dendrites within spinal cord and projects axon into muscle

Somatosensory neuron

Is in dorsal root ganglion system

Has peripheral axon with branched terminal endings

Central axon projects into spinal cord

Multipolar neuron

Both dendrites and an axon leave cell body

Bipolar neuron

An axon and a dendrite leave the cell body both extended slightly away from soma in middle

Pseudounipolar neuron

1 cytoplasmic extension leaves the cell body with a central and peripheral branch, soma sits on top of process

Theory of dynamic polarization

Transmission of neural signals and dendrites and cell bodies to axons

Receptive, dendrites, transmission, axon, effector, axon terminals

Theory of dynamic polarization states that almost every neuron has _____ part (___), ____ part (____), and _____ part (______)

Unipolar neuron

Type of neuron most found in most invertebrates

Dendritic branches are usually closer to soma

has 1 process with axonic and dendritic branches

Same branches often can both give and receive information

Membrane potential

Electrical potential difference across the neuronal membrane

Nerve impulses

Created from short term membrane potential changes

Action potential

Elementary unit of nerve impulses that axons use to get info across long distances

Have all or none property

Edgar Adrian

Experiment proved existence of action potential, and that neurons use frequency of action potentials to convey signal intensity by measuring nerve on outside

Frequency

Neurons use _____ of action potentials to help convey important information

Graded potentials

Membrane potential with continuous magnitude variation

Vary depending on input strength and sensitivity

Used by non-spiking neurons to transmit info

Synaptic potentials

Graded potential produced at post synaptic sites in response to neurotransmitter from presynaptic sites

Usually produced at dendritic spine and soma

Receptor potentials

Graded potentials induced at peripheral endings of sensory neurons

Non-spiking neurons

Neurons that don’t fire action potentials

Axon initial segment/ axon hillock

Site of action potential regulation and is next to soma

Temporal lobe

Lobe primarily responsible for auditory processing and new memories

Occipital lobe

Lobe primarily responsible for visual processing and recognition

Parietal lobe

Lobe primarily responsible for somatic sensation from face and body

Frontal lobe

Lobe primarily responsible for voluntary motor execution, planning, and judgement

Soma, axon initial segment

Synaptic signals travel through the _____ to the ______ to generate action potential

Membrane potential, chemical

Intraneural communication is from ____ changes and interneural communication is from _____ changes

Synaptic transmission

Process of presynaptic neuron releasing neurotransmitter to post synaptic neuron receiving neurotransmitter

Neural circuits

Inter connected neurons that work together for specific function

Afferents

Sensory axons that project from peripherial tissue to CNS

Efferents

Motor axons that project from CNS to peripheral targets

Excitatory neurons

When fire action potentials or release neurotransmitters that make post synaptic cells more likely to fire action potentials and include sensory and motor neurons

Inhibitory neurons

Make post synaptic cells less likely to fire action potentials

Interneurons

Neurons with axons confined to certian regions

Axons link different regions of nervous system

Projection neurons

Monosynaptic connection

Connection between same type of neurons

Disynaptic connection

Connection between 2 different types of neuron

Primary somatasensory cortex

Part of cerebral cortex that gets somatosensory information from body

Primary motor cortex

Sends output directly and indirectly to spinal cord motor neurons to control contractions

Convergent excitation

Several neurons synapse on same post synaptic neuron

Divergent excitation

1 neuron synapses on multiple post synaptic neurons iwth branched axons

Collaterals

Axon branches

Feed forward excitation

Serially connected excitatory neurons

Good for getting information across multiple areas

Recurrent/lateral excitation

Neurons that transmit parallel strains of information and can excite each other

Feed forward inhibition

Excitatory neuron synapses on excitatory and inhibitory neuron and inhibitory neuron synapses onto post synaptic excitatory neuron, inhibiting it

Feedback inhibition

Post synaptic excitatory neuron synapses on excitatory neuron which synapses on inhibitory which synapses back onto excitatory neuron

Lateral inhibition

Inhibitory neuron gets excitatory input from 1+ parallel neurons, leading to inhibition of many postsynaptic neurons