Card Set Information
Neural Conduction and Synaptic Transmission
What is the charge inside of the neuron compared to the outside and what is this state called ?
Resting Membrane Potential
: Inside the neuron is NEGATIVE (-70mV)
What are the four ions that contribute to the neuron and where are they placed ?
Negative Proteins Inside (these are always stuck within the neuron)
What factors contribute to EVEN distribution wihtin the ionic basis of the resting potential ?
: particles that are in areas of high concentration want to move to areas with low concentration
: like forces repel, opposites attract
What factors contribute to UNEVEN distribution within the ionic basis of the resting potential ?
: Membrane allows selective ions in
: Constantly working (3 NA
out / 2 K
The Sodium-Potassium Pumps are a what process ?
Where does the Postsynaptic Potentials (PSP) occur ?
Integrated near the Axon Hillox
Summation occurs over time and space (adding or combining a number of individual signals into one overall signal)
The Postsynaptic Potentials (PSPs) cause ?
: making the membrane potential LESS negative (-70 to -67 mV). This is EXCITATORY (more likely a neuron will fire) (EPSP)
: making the membrane potential MORE negative (-70 to -73 mV). This is INHIBITORY (less likely a neuron will fire) (IPSP)
EPSP and IPSP are ? (Like a rock thrown in the pond with ripples, need more then one small pebble)
: the greater the stimulus, the greater the response
: they get smaller as they travel
To fire an Action Potential there needs to be a reach of ?
Threshold of Activation (-65 mV)
More than one EPSP
The Action Potential is a what name ?
: when threshold is reached the neuron 'fires' and the Action Potential either occurs or does not
When threshold is reached, voltage-activated ion channels are opened (-70 to +50 mV)
What are the two aspects of the Refractory Periods (x1000/sec) ?
: IMPOSSIBLE to initiate another action potential
: HARDER to initiate another action potential (High/Supra can cause action potential)
What is the faster conduction than in unmyelinated axons ?
: Passive conduction along each myelin segment to next node of Ranvier
New action potential generated at each node
What does the Nurotransmitters release when Calcium comes into the cell and the NTs are dumped ?
What are the two classes of Receptors for a given NT ?
: open and close ion channels
: effect function of neuron & open and close channels
What happens within the Ionotrpoic Receptor ?
NT binds->associated ion channel opens or closes->PSP
NA+ channels open->NA+in->EPSP
K+ channels opened->K+ out->IPSP
What happens within the Metabotropic Receptors ?
NT binds->G protein breaks away->Ion channel opened/closed & 2
What are two ways that the activity in the synaptic cleft is turned off ?
: scoop up and recycle NT
: NT broken down by enzymes
What are the seven NT and what are their functions ?
: Mood, temperature regulation
: Pleasure, reward, motor movement
: Memory, muscle contraction
: Pain reduction, increase appetite
: Stress hormone, mood, sleep, brain arousal
: Main inhibitory NT
: Main excitory NT, sensory neuron
What are the two classes of NT molecules ?
Synthesized in the terminal button
and packaged in synaptic vesicles
Assembled in the cell body
, packaged in vesicles, and then transported to the axon terminal
What are considered the Small-Molecule NT ?
Monoamines:DA, NE, EPI, Seretonin
Unconventional NT (soluble gases, endocannabinoids)
What Amino Acid NT are Excitatroy and Inhibitory ?
: Excitatory in CNS
: Inhibitory in CNS
What is the Monoamines ?
Synthesized from a single amino acid (Tyrosine OR tryptophan)
Effects tend to be diffuse
What are the two procedures of Monoamines ?
: synthesized from tyrosine (Tyrosine->Dopamine->Norepinephrine->Epinephrine)
: synthesized from tryptophan (milk, turkey) creates serotonin
Where is Dophamin located and what does it involve ?
: involved in motor movement
: involved in reward & pleasure
: involved in STM & planning
What is the impact of Acetylcholine ?
Only NT released at neuromuscular junction (NMJ)
Can help with learning and memory
In Alzheimer's can be used during low stages to help
What are the different effects on Synaptic Transmission ?
: Increase OR facilitate NT activity
: Decrease OR inhibit NT activity
Drugs may alter NT activity at any point in its 'life cycle'
What are some examples of Agonists drugs ?
Cocaine - Dopamine
: Blocks reuptake- preventing the activity of the NT from being turned off
Benzodiazepines - GABA
: binds to the GABA molecule and increases the binding of GABA (glue)
What are some examples of Antagonist drugs ?
Atropine - ACH
: Binds and blocks muscarinic receptors in CNS (metabotropic)
Botox - ACH
: Blocks releach of Ach at nicotinic receptors at NMJ (ionotropic)