Neuroscience Flashcards
(30 cards)
What is an EEG or Electroencephalography
A device that monitors the electrical activity of the brain over time by means of recording electrodes attached to the surface of the scalp
Alpha Activity
-A brain wave pattern that occurs when a subject is physically and mentally relaxed and awake
-It’s a patterned basal wave of activity- only 70% of the population can cause this
TMS
-Involves stimulating the brain with a large current through a wire coil that is placed on a person’s head
-Allows scientists to temporarily enhance or depress activity in a specific area of the brain.
-This gives insight into the purpose of specific areas of the brain and their importance for certain functions
-May be helpful to treat depression, anxiety and eating disorders
PET or Positron-Emission Tomography
Examine brain function; map activity in the brain over time
Patient is injected with a substance that contains radioactive properties and when a certain area of the brain is active, it shows the liquid
Record biochemical changes, and maps the brain function with activity tracking overtime
What is the Nervous System Made of?
The Nervous system is made up of cells called Neurons (Nerve cells), they are the nervous systems communication specialists, they transmit information to, from and within the nervous system
Neuron Definition
Neuron: Individual cells in the nervous system that receive, integrate and transmit information
Glia Definition
Glia: cells that support, nurture and insulate neurons, remove debris when neurons die, enhance the formation and maintenance of synapses and modify neural functioning
- 90% of the brain cells are glia
-Communicate chemically with each other
Neurons rely on glial cells
Neuron Facts (5)
- Building blocks of the nervous system
- Each is unique and delicate like a snowflake
- Microscopic
- About 86 Billion in one brain
- Communicates between 5000-200,000 other neurons
Dendrite purpose/Def
Branches that receive information from other neurons and transmit it to the cell body
Soma or Cell body purpose/Def
Soma or Cell body: Keeps the neuron alive and decides whether it will fire
-Shaped like a sphere or pyramid
-Depends on input whether the message is fired
-Either the neuron fires or does not, it is not a spectrum of strength in firing
Axon Purpose and def:
Axon (Talkers): Extending fibre that conducts impulses away from the cell body and transmits them to other neurons
Myelin Shieth Purpose/Def
-Fatty insulation that may surround the axon of a neuron
-Helps protect the message being transported to avoid it interfering with a different message transfer
-Depending on the thickness, it can help increase the speed that which the impulse travels
-MS causes a lack of myelin
What language do Neurons speak
Neurons communicate through chemical and electrical languages
How do Neurons communicate
-When a neuron is stimulated, a change occurs between the inside and outside of the cell
-A sudden flow of +Na (positivity charged sodium) ions across a cell membrane, followed by an outflow of +K (positively charged potassium) ions
Synaptic cleft
minuscule space between neurons
Synapse
The site where transmission of a nerve impulse from one nerve cell to another occurs; it includes the axon terminal, the synaptic cleft and receptor sites in the membrane of the receiving cell
Synapse facts (5)
-When we are born, most synapses are not yet formed, but as we grow, they develop rapidly ( especially in infancy)
-Synapses grow through new learning experiences and stimulating environments
-Learning and stimulation also produce the greatest increases in synaptic complexity
With time, axons and dendrites continue to grow, and more and more connections grow in the brain’s neuro cells
-Unused synaptic connections prune away as the cells or branches die
-Brain circuits are continually changing in response to information, challenges, and changes in the environment
Action Potential
Action potential: A brief change in electrical voltage that occurs between the inside and outside of an axon when a neuron is stimulated; it serves to produce an electrical impulse
Neurotransmitter
Neurotransmitter: A chemical substance that is released by a transmitting neuron at the synapse and that alters the activity of a receiving neuron.
-What any neuron does at any moments depends on the net effect of the messages being sent by other neurons
-Thousands of messages of different kinds are sent to each neuron
How a Neurotransmitter Works
-Exist within the brain, spinal cord, peripheral nerves and in certain glands
-When a neural impulse reaches the axon terminals button like tip it has to get its message across the synaptic cleft to another cell
-To do this, synaptic vesicles which are tiny sacs in the tip of the axon terminal open, and release a few thousand molecules of a chemical substance called a neurotransmitter
-These molecules diffuse across the synaptic cleft
The neurotransmitter binds briefly with receptor site, a special molecule in the membrane of the receiving neurons dendrites
-Neurotransmitters fit like a key in a lock within the receptor sites
-Upon receiving the neurotransmission, the receiving neuron holds a change which is either excitatory or inhibitory depending on the neurotransmitter
Excitatory and Inhibitory
INHIBITION AND EXCITATION: Excitatory increases likelihood of the receiving neuron firing and inhibitory does the opposite
Serotonin: Affects neurons involved in sleep, appetite, pain suppression and mood
Depression is related to low serotonin levels
Low levels of serotonin and norepinephrine have been associated with severe depression
Dopamine
Dopamine: Affects neurons involved in voluntary movement, learning, memory and emotion
Parkinson’s disease involves a loss of cells that produce dopamine (dopaminergic neurons: nerves that produce dopamine)
Acetylcholine
Acetylcholine: Affects neurons involved in muscle action, cognitive functioning, memory and emotion
ONLY neurotransmitter with conversation to the body and movement
