neurophysiology

Question 1

Axon hillock

Answer 1

the part of the neuron at which APs are normally generated (due to a low threshold membrane potential)

Question 2

‘Long’ sensory receptors

Answer 2

Send axons to the CNS and fire APs

Question 3

‘Short’ sensory receptors

Answer 3

Synapse on a second order neuron immediately; often have graded potentials

Question 4

Examples of long sensory receptors

Answer 4

Cutaneous receptors, olfactory recepors

Question 5

Examples of short sensory receptors

Answer 5

Receptors for taste, vision and hearing

Question 6

Feedforward inhibition

Answer 6

The phenomenon in which the downstream antagonistic pathway is inhibited at the same time as the agonist pathway is stimulated.

Question 7

Feedback inhibition (synapses)

Answer 7

When the excited cell both excited downstream pathways and contacts inhibitory interneurons such as Renshaw cells to inhibit itself.

Question 8

PGE2 acts on …

Answer 8

EP4 (leads to Gs signalling, pain sensitisation)

Question 9

Exogenous opiates

Answer 9

Morphine, diamorphine, codeine, etorphine

Question 10

Opioid antagonist

Answer 10

Naloxone

Question 11

Gabapentin

Answer 11

Decreases cell surface localisation of a2d1 subunit of CaV

Question 12

Lidocaine

Answer 12

blocks NaVs

Question 13

Ketamine

Answer 13

NMDA antagonist

Question 14

Ziconotide

Answer 14

N-type CaV blocker; given intrathecally

Question 15

Cocaine

Answer 15

Inhibits reuptake of NA, DA and 5-HT

Question 16

Brain activity; alpha rhythms

Answer 16

quiet waking state; low amplitude at 15-60 Hz frequency

Question 17

Brain activity; beta rhythms

Answer 17

Active awake state; low amplitude, at 8-13 Hz frequency

Question 18

Stage 1 sleep

Answer 18

Theta rhythms; 4-8 Hz, increasing amplitude

Question 19

Stage 2 sleep

Answer 19

low frequency, increased amplitude, sleep spindles or K complexes

Question 20

Delta rhythms

Answer 20

Stage 3 or 4 sleep

Question 21

Functions of sleep

Answer 21

Restoration of mental and bodily functions, brain development (children), memory consolidation.

Question 22

Role of Schwann cells in axon regeneration

Answer 22

Promote regeneration in the PNS if there is a living track of them.

Question 23

When does a neuroma form?

Answer 23

When there is a break of more than 1 cm in the track of living Schwann cells

Question 24

Why is the CNS non-permissive for axon growth?
ECM
Oligodendrocytes
Glial cells in general
Astrocytes

Answer 24

ECM; lacks growth promoting molecules such as laminin
Oligodendrocytes produce Nogo
Glial cells in general produce CSPGs (chondroitin sulphate proteoglycans)
Astrocytes form the glial scar

Question 25

Strategies for repair in the CNS

Answer 25

``` Add neurotrophic factors Graft peripheral nerve cells Block Nogo Add Chondroitinase Block downstream effects using drugs/gene knockdown. ```

Question 26

Where can you get stem cells for neural grafting

Answer 26

1) Embryonic sub. nigra for Parkinson's. 2) Neural stem cells; from ventricular and subventricular zone in fetal brain. In adult brain from olfactory bulb or dentate gyrus. 3) induced pluripotent stem cells

Question 27

Aa nerve fibres

Answer 27

Carry information from muscle spindles and Golgi tendon organs.

Question 28

Ad nerve fibres

Answer 28

Carry fast sharp pain and temperature

Question 29

C fibres

Answer 29

Carry slow burning pain.

Question 30

Role of Shh

Answer 30

Induce floorplate (high conc) and motor neurons (low conc)

Question 31

Neural tube becomes

Answer 31

CNS

Question 32

Neural folds become

Answer 32

PNS

Question 33

Destination of neural crest cells

Answer 33

Dorsal root ganglia, sympathetic ganglia, schwann cells.

Question 34

NGF

Answer 34

Neurotrophic, neurotropic, diffusible and attractive

Question 35

Netrin

Answer 35

Neurotrophic, neurotropic, diffusible either attractive or repellent.

Question 36

CAMs

Answer 36

Contact attractive

Question 37

Semaphorins

Answer 37

Contact repellent (also ephrins and proteoglycans)

Question 38

Ephrins

Answer 38

Contact repellent (also semaphorins and proteoglycans)

Question 39

Proteoglycans

Answer 39

Contact repellent or signalling

Question 40

How does L-DOPA enter the CNS

Answer 40

Using a specialised transport system for essential amino acids

Question 41

Where is CSF found?

Answer 41

In the central canal of the spinal cord, in the ventricles, in the subarachnoid space and in the cisterns.

Question 42

Drugs used in Alzheimer's disease

Answer 42

Memantine (NMDA antagonist) - unknown mechanism. | Cholinesterase inhibitors delay disease progression; tacrine, donezepil.

Question 43

Future treatments for Alzheimer's.

Answer 43

Cyclohexanehexol; blocks aggregation of beta-amyloid. Blocking B or y secretase. Inhibiting kinases that phosphorylate tau NGF?

Question 44

Dyskinesia

Answer 44

Involuntary muscle movements such as chorea or tremor.

Question 45

pain nucleus of thalamus

Answer 45

VMPO