Neurophysiology (Chapter 2)

Calcium

________ (Ca++) ions predominantly on the outside- has a double charge- every ion that enters the intracellular fluid has double the charge of a sodium ion.

Sodium

________ and calcium have greater potential to get thru the membrane.

ERP

________ (Evoked Response Potential):: EEGs configured in a new way, give a stimulus and look how neurons respond immediately before or after- measured over time.

Ion

________:: an electrically charged atom or molecule.

Cowboys

Unmyelinated axons is like doing the wave at a(n) ________ game; myelinated axons is like standing in a circle squeezing palms.

IPSPs

________ are very important to balance and modulate the neurons.

Hyperpolarization

________:: cell becomes more neg on the inside (further from 0)

EEG

________:: single electrode or complex electrodes; read the electrical charge of potentially millions of neurons; no specificity for cell by cell actions- looking for gross activity of neurons acting together.

Depolarization

________:: cell becomes less neg on the inside (closer to 0)

Chloride

________ (Cl)- wants to enter cell via concentration; stay outside via voltage.

Potassium

________ (K+) wants to leave cell via concentration; stay inside via voltage.

threshold of excitation

Voltage- gated channels only open when the membrane potential is at the ________.

Microelectrode

________:: tool used to measure charge of the inside /outside of a neuron.

Cell membrane

________:: a phospholipid bilayer.

Neurophysiology

________:: study of life processes of neurons.

Ion channels

________ are on the dendrites /dendritic spines, cell body, every surface that grows.

Intracellular fluid

________:: inside of our cells have fluid, negative charge usually.

Calcium

________ enters due to the concentration gradient and turns on second messengers.

Sodium

________ (Na+) wants to enter cell via concentration; enter cell via voltage.

Threshold of excitation

________:: the amount of depolarization required to initiate an action potential.

Calcium

________ (Ca++) wants to enter cell via concentration; enter cell via voltage.

Neurophysiology

study of life processes of neurons

Intracellular fluid

inside of our cells have fluid, negative charge usually

Extracellular fluid

surrounding cells, positive charge usually

Microelectrode

tool used to measure charge of the inside/outside of a neuron

Ion

an electrically charged atom or molecule

Cell membrane

a phospholipid bilayer

Phosphate groups w/inactive arms naturally align themselves in tight rows

fat soluble things can pass through, otherwise molecules must have a channel to go through (very specific channel)

Threshold of excitation

the amount of depolarization required to initiate an action potential

Resting

what does the cell look like when the neuron is not firing

Organic anions (A-)

big, lots of molecular weight and potassium ions (K+)

Naturally neg because A

is so prevalent

Depolarization

cell becomes less neg on the inside (closer to 0)

Hyperpolarization

cell becomes more neg on the inside (further from 0)

Voltage gradient (electrostatic forces)

in high positive concentration, they will be drawn to neg charge; in high neg concentration, they will be drawn to pos charge → opposites attract

Ex

sodium prefers to go thru a channel, but can sneak thru membrane a little bit

Absolute refractory period

neuron cannot fire again

Relative refractory period

neuron can potentially fire again, sodium-potassium pump working super hard

Hearing and touch pathways begin myelinating in the womb

majority occurs after birth

Tied to experience

neurons that fire more regularly will be more myelinated

EPSP (Excitatory Post Synaptic Potential)

depolarization; Ca++, Na+ will eventually reach threshold of excitation

IPSP (Inhibitory Post Synaptic Potential)

hyperpolarization; Cl-, K+