Intro to neuro and epilepsy

Question 1

4 functions of ion channels

Answer 1

• set resting membrane potential
• facilitate depolarization and repolarization
• regulate intracellular Ca
• signal transduction

Question 2

types of ion channel gating mechanisms

Answer 2

• voltage
• chemical (ie ligand)
• mechanical

Question 3

3 properties of ion channels

Answer 3

• they conduct ions
• ion specific
• open and close by specific mechanisms

Question 4

channel that is passively open

Answer 4

K

Question 5

Nernst equation use

Answer 5

determines the potential at which driving forces and chemical forces are equal (net current is ZERO)

Question 6

equilibrium potential

Answer 6

when net current for that ion is zero

Question 7

resting membrane potential value

Answer 7

-70

Question 8

how are Na and K concentration gradients maintained

Answer 8

Na/K ATPase

Question 9

3 rules of ion movement

Answer 9

1. ions only cross through open channels
2. ions seek their reversal potential
3. ion movement changes neuron’s membrane potential

Question 10

things that subunit assembly of ion channels determines

Answer 10

• ionic permeability
• conductance
• kinetics
• pharmacology
• desensitization
• voltage sensitivity
• intracellular regulation

Question 11

drugs can target channels in specific states to

Answer 11

selectively inhibit rapidly depolarizing tissue or resting tissue
more specificity

Question 12

business end subunit of voltage gated sodium channels

Answer 12

alpha

Question 13

different types of alpha subunits causes…

Answer 13

the channels to be specific to the tissue they are in

Question 14

channel that contributes to resting membrane potential

Answer 14

K

Question 15

channel that generates action potentials

Answer 15

Na

Question 16

channel largely responsible for action potential repolarization

Answer 16

K

Question 17

voltage gated calcium channels are involved in…

Answer 17

• neurotransmitter secretion
• hormone secretion
• muscle contraction
• action potentials
• gene expression
• 2nd messenger cascades

Question 18

receptors responsible for inhibitory postsynaptic potential generation

Answer 18

GABA receptors

permeable to Cl

Question 19

glutamate opens which channels

Answer 19

AMPA

NMDA

Question 20

AMPA permeable to

Answer 20

Na»>K, sometimes Ca

Question 21

NMDA permeable to

Answer 21

Na, K, Ca

Question 22

AMPA and NMDA location

Answer 22

postsynaptic cells

Question 23

NMDA receptor ligands

Answer 23

needs 2 glutamate and glycine

Question 24

what blocks NMDA receptors and how is it removed

Answer 24

Mg ion

as neuron is depolarized via AMPA the Mg is removed

Question 25

to pass BBB molecules must be

Answer 25

very lipid soluble or have a transporter

Question 26

role of BBB

Answer 26

isolate brain's extracellular fluid

Question 27

seizure

Answer 27

clinical manifestation of an abnormal, hypersynchronus excessive excitation of a population of neurons

Question 28

epilepsy

Answer 28

tendency toward recurrent seizures unprovoked by systemic or neurologic insults

Question 29

epileptogenesis

Answer 29

sequence of events that converts a normal neuronal network into a hyperexcitable network prone to seizures

Question 30

3 conditions for diagnosing epilepsy (only one needed)

Answer 30

1. at least 2 unprovoked seizures occurring >24h apart 2. one unprovoked seizure and chance of further seizures at similar risk as general populous after 2 seizures in the next 10 years 3. diagnosis of epilepsy syndrome

Question 31

comorbidities associated with epilepsy

Answer 31

depression cognitive disabilities sleep disorders anxiety

Question 32

interictal

Answer 32

in between seizures

Question 33

how to determine between focused and general seizures using EEG

Answer 33

focused will have interictal spikes in only one lead or leads close together while general will have spikes in most/all leads

Question 34

focal seizures

Answer 34

seizure localized to one area of the brain

Question 35

clinical manifestations of focal seizures

Answer 35

- varies with site of origin, but most have aura associated | - may or may not have impaired consciousness

Question 36

focal to bilateral tonic-clonic seizures

Answer 36

- assumed to begin as a focal seizure and developing bilaterally - variable length and intensity of tonic and clonic phases - often postictal confusion/somnolence

Question 37

tonic phase

Answer 37

stiffening

Question 38

clonic phase

Answer 38

jerking

Question 39

types of generalized seizures

Answer 39

``` absence myoclonic clonic atonic tonic tonic-clonic ```

Question 40

excitation mechanism of seizure generation

Answer 40

too much inward Na and Ca currents due to neurotransmitters glutamate and aspartate

Question 41

inhibition mechanism of excitation

Answer 41

to little inward Cl and outward K currents; GABA receptors are involved

Question 42

temporal lobe epilepsy (TLE)

Answer 42

- often result of head injuries, tumors, infections, strokes - may have long latent period - difficult to treat with current therapies

Question 43

neuronal factors that modify neuronal excitability

Answer 43

- ion channel type, #, distribution - modification of receptors - activation of 2nd messengers - gene expression modification

Question 44

extra-neuronal factors that modify neuronal excitability

Answer 44

- changes in extracellular ion concentration - remodeling of synapse - modulation of transmitter metabolism or reuptake - inflammation

Question 45

treatment options for epilepsy

Answer 45

- surgery to remove part of brain - brain implant of therapeutic device - ketogenic diet - antiseizure drugs

Question 46

vagus nerve stimulation is approved for

Answer 46

- partial epilepsy aged 12 and up - seizure not helped enough by drugs - adults w/ depression not helped by other treatments