intro neuro

Question 1

what is convergence?

Answer 1

neurone has synaptic input from a variety of neurones

Question 2

what is divergence?

Answer 2

neurone provides synaptic input to many other neurones

Question 3

what is spatial summation

Answer 3

many neurones exert same effect on the post synaptic membrane

Question 4

what is temporal summation

Answer 4

several APs arrive in succession to have a greater effect than just one AP

Question 5

how do EPSPs and IPSPs decay?

Answer 5

with exponential time course

Question 6

what do IPSPs lead to?

Answer 6

hyperpolarisation on the post synaptic membrane

Question 7

what are the 3 classes of neurotransmitter?

Answer 7

amino acids; amines and purines; peptides

Question 8

examples of amino acid neurotransmitter

Answer 8

glutamate, GABA, glycine

Question 9

examples of amines and purines neurotransmitters

Answer 9

Ach, NA, 5HT, ATP

Question 10

Examples of peptide neurotransmitters

Answer 10

CCK, substance P, vasopressin

Question 11

what are fast receptors called and how do they work

Answer 11

Ionotropic, directly linked to ion channels

Question 12

what are slow receptors and how do they work

Answer 12

metabotropic, coupled to effector ion channel

Question 13

what are the 3 types of glutamate receptor?

Answer 13

NMDA glutamate receptors, non NMDA receptors and metabotropic receptors

Question 14

which glutamate receptors are fast receptors

Answer 14

NMDA and non NMDA

Question 15

how does the metabotropic glutamate receptor work

Answer 15

more long term effects. linked to G proteins and 2nd messenger coupling.

Question 16

whats the difference between NMDA and non NMDA receptors

Answer 16

non NMDA is not affected by NMDA, activated by AMPA and kainite. NMDA binds NMDA receptor

Question 17

what are the 2 types of GABA receptor

Answer 17

GABAa and GABAb

Question 18

what is the structure of GABAa

Answer 18

2 alpha, 2 beta, 1 gamma

Question 19

how does GABAa work?

Answer 19

opens channel permeable to Cl- membrane hyperpolarises

Question 20

how does GABAb work?

Answer 20

activate K+ channels causing hyperpolarisation and inhibits APs

Question 21

what is the structure of GABAb?

Answer 21

7 transmembrane domains which are coupled to G proteins

Question 22

what effects do ACHrs have ?

Answer 22

both inhibitory and excitatory, mainly excitatory

Question 23

how do mACHrs work?

Answer 23

coupled to G proteins. quite slow

Question 24

what are the subtypes of mACHrs

Answer 24

M1-5

Question 25

what are M1,3,5 coupled to?

Answer 25

phospholipase C

Question 26

what are M2,4 coupled to?

Answer 26

negatively coupled to adenylyl cylcase

Question 27

what are the major subtypes of dopamine receptors

Answer 27

D1 and D2

Question 28

where are dopamine receptors found

Answer 28

throughout CNS, in mesostriatal tract and nigrostriatal tract

Question 29

what does degeneration of tracts associated with dopamine lead to

Answer 29

parkinsons

Question 30

what type of transmission are serotonin receptors

Answer 30

metabotropic

Question 31

Are 5HT1 receptors inhibitory or excitatory

Answer 31

inhibitory (5HT2 excitatory)

Question 32

what stain can be used for CNS tissue

Answer 32

Weigerts stain

Question 33

what colour does white matter stain

Answer 33

stains darkly as myelinated it contains lipids which the stain is for (grey matter unstained)

Question 34

is there connective tissue in the CNS

Answer 34

NO CONNECTIVE TISSUE IN CNS

Question 35

what is a fascicle

Answer 35

contains bundles of axons

Question 36

how much of brain is grey matter and how much oxygen does it use

Answer 36

40% of brain. uses 96% of O2

Question 37

what fibres interconnect on the same side

Answer 37

association fibres

Question 38

what fibres interconnect on the opposite side

Answer 38

commissural fibres

Question 39

are there more neurones or neuroglial cells in the CNS

Answer 39

10x more neuroglial cells

Question 40

what are the neuroglial cell types

Answer 40

oligodendrocytes, astrocytes, ependymal cells, microglia

Question 41

what is the function of oligodendrocytes

Answer 41

forms myelin sheath, in 10-15 axons

Question 42

what are the functions of astrocytes

Answer 42

blood brain barrier, regulate K+, glutamate and Ca2+, produce growth factors for the production of neurones, help in neural migration, some become neurones, synapse formation

Question 43

what is the function of microglia

Answer 43

defence (mobile)

Question 44

what is the function of ependymal cells

Answer 44

line ventricular system

Question 45

what cells line the entire CNS part of the blood

Answer 45

endothelial cells

Question 46

how are neurones grouped

Answer 46

nuclei, laminae or reticular formation