Term
| Caton and Electroencephalogram |
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Definition
First to attempt to measure electrical currents of the brain using a voltmeter and electrodes on the skull
Electrical brain graph that records electrical activity through the skull or from the brain and represents graded potentials of many neurons |
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Term
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Definition
Flow of information in the nervous system is too slow to be a flow of electricity
Nerve conduction: 30-40 meters/second
Electricity: 3 x 108 meters/second |
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Term
| Giant Squid, Microlectrodes and Oscilloscope |
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Definition
Giant Axon of the Squid
Much larger in diameter than human axons
Humans: 1 to 20 micrometers
Squid: Up to 1 millimeter (1000 micrometers)
Easier on which to perform experiments
Used by Hodgkin and Huxley in the
1930s and 1940s
A set of electrodes small enough to place on or into an axon.
Can be used to:
Measure a neuron’s electrical activity
Deliver an electrical current to a single neuron (stimulation)
A device that serves as a sensitive voltmeter
Used to record voltage changes on an axon |
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Term
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Definition
Cations
Positively charged ions
Examples: Sodium (Na+), potassium (K+)
Anions
Negatively charged ions
Examples: Chloride (Cl-), protein molecules (A-) |
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Term
| 4 charged parts that take place in producing resting potential |
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Definition
Sodium (Na+) and chloride (Cl-)
Higher concentration outside cell
Potassium (K+) and large proteins (A-)
Higher concentration inside cell |
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Term
| maintaing resting potential: ungated potassium and chloride channels, gated sodium channels and sodium potassium pumps |
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Definition
Large A- molecules cannot leave cell: make inside negative
Ungated channels allow K+ and Cl- to move into and out of cell more freely, but gated sodium channels keep out Na+ ions
Na+-K+ pumps extrude Na+ from intracellular fluid and inject K+
Potassium (K+) and large proteins (A-)
Higher concentration inside cell |
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Term
| role of ions in summation at axon hillock |
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Definition
| The influx and efflux of ions is what is being summed |
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Term
| Lowei's discovery of acetlycholine |
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Definition
Frog heart experiment
Role of the the vagus nerve and the neurotransmitter acetylcholine (ACh) in slowing heart rate |
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Term
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Definition
Junction where messenger molecules are released when stimulated by an action potential
Synaptic Vesicle
Organelle consisting of a membrane structure that encloses a quantum of neurotransmitter
Synaptic Cleft
Gap that separates the presynaptic membrane from the postsynaptic membrane
Presynaptic Membrane
Membrane on the transmitter - output side of a synapse
Postsynaptic Membrane
Membrane on the transmitter - input side of a synapse |
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Term
| Neurotransmitter synthesis and storage |
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Definition
Synthesized in the Axon Terminal
Building blocks from food are pumped into cell via transporters: protein molecules embedded within the cell membrane
Synthesized in the Cell Body
According to instructions contained in the DNA
Transported on microtubules to axon terminal |
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Term
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Definition
At the terminal, the action potential opens voltage-sensitive calcium (Ca2+) channels
Ca2+ enters the terminal and binds to the protein calmodulin forming a complex
Complex causes some vesicles to empty their contents into the synapse, and others to get ready to empty their contents |
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Term
| neurotransmitter receptor action |
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Definition
After being released, the neurotransmitter diffuses across the synapse and activates receptors on the postsynaptic membrane
Transmitter-Activated Receptors
Protein embedded in the membrane of a cell that has a binding site for a specific neurotransmitter
Neurotransmitter may
Depolarize the postsynaptic membrane causing excitatory action on the postsynaptic neuron
Hyperpolarize the postsynaptic membrane causing inhibitory action on the postsynaptic neuron
Initiate other chemical reactions that modulate either the excitatory or inhibitory effect, or influence other functions of the receiving neuron
(autoreceptors and quantum) |
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Term
| deactivation of neurotransmitter |
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Definition
Accomplished In At Least Four Ways
Diffusion away from synaptic cleft
Degradation by enzymes in the synaptic cleft
Reuptake into the presynaptic neuron for subsequent re-use
Taken up by neighboring glial cells |
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Term
| Type I and Type II synapses |
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Definition
Type I Synapse
Excitatory
Typically located on dendrites
Round vesicles
Dense material on membranes
Wide cleft
Large active zone
Type II Synapse
Inhibitory
Typically located on cell body
Flat vesicles
Sparse material on membranes
Narrow cleft
Small active zone |
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Term
| four criteria for identifying neurotransmitters |
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Definition
The chemical must be synthesized in the neuron or otherwise be present in it
When the neuron is active, the chemical must be released and produce a response in a some target
The same response must be obtained when the chemical is experimentally placed on the target
A mechanism must exist for removing the chemical from its site of action after its work is done |
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Term
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Definition
Neuropeptide
A multifunctional chain of amino acids that act as a neurotransmitter
Synthesized from mRNA on instructions from the cell’s DNA
Do not bind to ion channels; do not have direct effects on the voltage of the postsynaptic membrane
Examples:
Opioids
Neurohypophyseals
Secretins
Insulins
Gastrins
Somatostatins
Corticosteroids |
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Term
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Definition
Synthesized in cell, as needed
Easily crosses cell membrane
Examples:
Nitric Oxide (NO)
Carbon Monoxide (CO) |
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Term
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Definition
Embedded membrane protein with two parts
A binding site for a neurotransmitter
A pore that regulates ion flow to directly and rapidly change membrane voltage |
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Term
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Definition
Embedded membrane protein with a binding site for a neurotransmitter but no pore
Linked to a G protein that can affect other receptors or act with second messengers to affect other cellular processes |
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Term
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Definition
| Belongs to a family of guanyl-nucleotide-binding proteins coupled to metabotropic receptors that, when activated, bind to other proteins |
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Term
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Definition
A chemical that carries a message to initiate a biochemical process
Activated by a neurotransmitter (the first messenger)
Examples
Alter ion flow in a membrane channel
Formation of new ion channels
Production of new proteins |
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Term
| cholinergic neuron and nicotine Ach recptor |
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Definition
Cholinergic Neuron
Neuron that uses acetylcholine (ACh) as its main neurotransmitter
Excites skeletal muscles to cause contractions
Nicotinic ACh Receptor
Ionotropic receptor at which acetylcholine and the drug nicotine act to open an pore and allow the flow of ions through the receptor pore |
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Term
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Definition
Activating System
Neural pathways that coordinate brain activity through a single neurotransmitter
Cell bodies are located in a nucleus in the brainstem and their axons are distributed through a wide region of the brain
Four Systems
Cholinergic, Dopaminergic, Noradrenergic, and Serotonergic |
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Term
| Brain Basis for Alzheimer's |
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Definition
Degenerative brain disorder that first appears as progressive memory loss and later develops into generalized dementia
Involves cholinergic system |
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Term
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Definition
Behavioral disorder characterized by delusions, hallucinations, disorganized speech, blunted emotion, agitation or immobility, and a host of other symptoms
Involves dopaminergic system |
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Term
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Definition
Mood disorder characterized by prolonged feelings of worthlessness and guilt, the disruption of normal eating habits, sleep disturbances, a general slowing of behavior, and frequent thoughts of suicide
Involves noradrenergic system |
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Term
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Definition
Behavioral disorder characterized by compulsively repeated acts (e.g., hand washing) and repetitive, often unpleasant, thoughts (obsessions)
Involves serotonergic system |
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Term
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Definition
Learning behavior in which a response to a stimulus weakens with repeated stimulus presentations
Example:
Gill withdrawal response in the marine snail Aplysia californica |
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Term
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Definition
Learning behavior in which the response to a stimulus strengthens with repeated presentations of that stimulus because the stimulus is novel or stronger than normal
For example, after habituation has occurred |
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Term
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Definition
(LTP)
In response to stimulation at a synapse, changed amplitude of an excitatory postsynaptic potential that lasts for hours to days or longer
Plays a part in associative learning
A strong burst of electrical stimulation applied to the presynaptic neuron produces an increase in the amplitude of the EPSP in the postsynaptic neuron
First recorded in the hippocampus by Bliss and Lømø in 1973
Field Potential:
EPSPs from many neurons; recorded with extracellular electrodes
Two events must occur close together in time for NMDA receptors to open
Depolarization of postsynaptic membrane, which displaces Mg2+ from pore (strong electrical stimulus)
Activation by glutamate from the presynaptic neuron (weak electrical stimulus)
Strong and weak stimuli have been paired |
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Term
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Definition
Study of the relations between brain function and behavior
Origins: Paul Broca (mid 19th century) discovered the link between left hemisphere damage and language difficulties |
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Term
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Definition
Behavioral Neuroscience
Study of the biological basis of behavior
Includes the study of both humans and laboratory animals
Major challenge is to develop methods for studying both normal and abnormal behavior
Ethology:
The study of animal behavior |
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Term
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Definition
Place learning
Rat must find platform using external cues
Matching-to-place learning – Platform is in the same location each trial, but a different location each day
Landmark version – Platform is identified by a cue on the wall |
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Term
| skill reaching tasks with rats |
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Definition
Skilled reaching task (Whishaw and Kolb, 2005)
Rats are trained to reach through slot to obtain food
Movements can be broken down into segments, which are differently affected by different types of neurological perturbation |
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Term
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Definition
First technique used, developed by Karl Lashley (1920s)
Ablation: removal or destruction of tissue |
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Term
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Definition
| Surgical instrument that permits the researcher to target a specific part of the brain |
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Term
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Definition
First used by Wilder Penfield to stimulate the cerebral cortex of humans during neurosurgery
Rats with electrodes in the lateral hypothalamus will eat whenever the stimulation is turned on.
Self-stimulation: Given the opportunity, rats will press a lever to obtain the current
The stimulation affects a neural circuit involving both eating and pleasure |
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Term
| Transcranial magnetic stimulation |
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Definition
Transcranial Magnetic Stimulation (TMS)
Procedure in which a magnetic coil is placed over the skull to stimulate the underlying brain
Used either to induce behavior or to disrupt ongoing behavior |
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Term
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Definition
Measures the summed graded potentials from many thousands of neurons
Reveals features of the brain’s electrical activity
The EEG changes as behavior changes
An EEG recorded from the cortex displays an array of patterns, some of which are rhythmical
The living brain’s electrical activity is never silent, even when the person is asleep or comatose |
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Term
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Definition
Event-Related Potentials (ERPs)
Complex electroencephalographic waveforms related in time to a specific sensory event
To counter noise effects, the stimulus is presented repeatedly, and the recorded responses are averaged
Advantages
Noninvasive
Low cost |
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Term
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Definition
Magnetoencephalogram (MEG)
Magnetic potentials recorded from detectors placed outside the skull
Permit a 3-D localization of the cell groups generating the measured field
Higher resolution than ERP
Disadvantage: high cost |
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Term
| Single cell recordings of action potential |
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Definition
Measuring single-neuron action potentials with fine electrodes
Electrodes placed next to cells (extracellular recording) or inside them (intracellular recording) |
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Term
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Definition
Neurons maximally responsive to specific locations
Discovered in the hippocampus of rats |
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Term
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Definition
Computerized Tomography (CT)
X-ray technique that produces a static, three-dimensional image of the brain in cross section |
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Term
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Definition
Magnetic Resonance Imaging (MRI)
Technique that produces a static, three-dimensional brain image by passing a strong magnetic field through the brain, followed by a radio wave, then measuring the radiation emitted from hydrogen atoms |
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Term
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Definition
Functional Magnetic Resonance Imaging (fMRI)
Magnetic resonance imaging in which changes in elements such as iron or oxygen are measured during the performance of a specific behavior
Used to measure cerebral blood flow during behavior or resting
Patients must lie motionless |
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Term
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Definition
Positron Emission Tomography (PET)
Imaging technique that detects changes in blood flow by measuring changes in the uptake of compounds such as oxygen or glucose
Used to analyze the metabolic activity of neurons
Radioactive molecules are injected into the bloodsteam
Very expensive |
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Term
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Definition
Near-Infrared Spectroscopy (NIRS)
Noninvasive technique that gathers light transmitted through cortical tissue to image blood-oxygen consumption
Advantage: Easy to hook subjects up
Disadvantage: Measurement restricted to cortical activity (light does not penetrate the brain very far) |
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Term
| Brain-derived neurotrophic factor |
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Definition
(BDNF)
Plays important role in stimulating neural plasticity
Gene related to BDNF has two alleles: Val 66Met and Val 66Val |
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Term
| Epigenetic research findings |
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Definition
Changes in gene expression related to experience
Wide range of experiential factors
Chronic stress, traumatic events, drugs, culture, disease
Cumulative experiences affect how genes work
Fraga and colleagues (2005)
Twins have nearly identical patterns of gene expression early in life, but remarkably different by age 50
Szyf, Meaney, and colleagues (2008)
Amount of maternal attention given to newborn rat pups alters gene expression in their adult hippocampus |
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Term
| Epigenetic research findings |
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Definition
Changes in gene expression related to experience
Wide range of experiential factors
Chronic stress, traumatic events, drugs, culture, disease
Cumulative experiences affect how genes work
Fraga and colleagues (2005)
Twins have nearly identical patterns of gene expression early in life, but remarkably different by age 50
Szyf, Meaney, and colleagues (2008)
Amount of maternal attention given to newborn rat pups alters gene expression in their adult hippocampus |
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Term
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Definition
| s a semi-invasive sampling technique that is used for continuous measurement of free, unbound analyte concentrations in the extracellular fluid of virtually any tissue. |
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Term
| five types of chemical synapse |
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Definition
chemical neurotransmitters into extracellular fluid
or into bloodstream as hormones
dendrite to dendrite
axon terminal to dendrite or cell bodies or muscles, or other axons or other synapses |
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