Action selection in health science

Question 1

what is computational neuroscience

Answer 1

mathematical modelling of core features of cells, circuits, and neural networks

Question 2

how is computational neuroscience used

Answer 2

to develop predictions and test hypotheses

Question 3

how is animal movement described as action sequences

Answer 3

hierarchial
serially organised (reactions occur together and converge)

Question 4

what does the central complex contain

Answer 4

protocerebral bridge (pb)
fan shaped body (fb)
ellipsoid body (ep)
noduli (no)

Question 5

how is EB neuron firing measured

Answer 5

picrotoxin (triggers inhibitory GABAergic neurons)
sum of net output = increased firing rate

Question 6

what core features of neurons can be mathematically modelled

Answer 6

potassium current
leakage current
membrane potential
gates
sodium current

Question 7

what does an action potential resemble

Answer 7

sine wave (idealised)/rotating phasor

Question 8

what is an action potential

Answer 8

membrane potential/time

Question 9

what is circular frequency equal to

Answer 9

angular velocity (w)
period defines frequency
w = 2pi/T

Question 10

what is frequency

Answer 10

number of cycles per second (Hz)
1/T

Question 11

what does many APs mean

Answer 11

many quasi-periodic rotating phasors
many sine waves (resembles neural activities within a circuit)

Question 12

what is the fourier transform

Answer 12

idealised sine waves integrate

Question 13

which domains are involved

Answer 13

time domain s(t) is converted into a frequency domain s(w)

Question 14

role of the sinusoidal functions

Answer 14

defines circuit/neural activity

Question 15

types of neural activity

Answer 15

periodic
aperiodic

neural activity is often aperiodic

Question 16

what happens to rotating behaviour

Answer 16

coalesce in the centre
each 360 turn in the phase space = burst of a neuron

Question 17

what is the attractor

Answer 17

trajectory/point in a phase space to which the system will converge from a set of initial coordinates

Question 18

features of neural circuits

Answer 18

-non linear systems may have one or more attractor
-operate near instability for rapid response
-dynamic systems

Question 19

lorenz attractor

Answer 19

open, non-equilibrium systems are dynamic, non-linear phase transitions of attractor states

Question 20

types of attractors

Answer 20

-periodic
-quasi periodic
-chaos

Question 21

what is action selection

Answer 21

coordinates motor actions and their organisation into action sequences by facilitating appropriate motor programmes while inhibiting competing ones

(right thing at the right time)

Question 22

BG direct pathway

Answer 22

(D1)
striatum
–> GPi/Snr
–> Thalamus

Question 23

BG indirect pathway

Answer 23

(D2)
striatum
–> GPe
–> STN
–> GPi/Snr
–> thalamus

Question 24

what forms the striatum

Answer 24

caudate nucleus + putamen

Question 25

channelrhodopsin and optogenetics experiment | Kravitz et al., 2010

Answer 25

D1 laser on: mouse running, direct pathway facilitates movement D2 laser on: Indirect pathway inhibits unwanted movement

Question 26

how is action selection coordinated by the direct and indirect pathway

Answer 26

both pathways activated at the same time different from accelerator and break model

Question 27

examples of impaired action selection

Answer 27

-dyskinesia -motor neuron disease -PD -FTD (fronto-temporal dementia - unwanted behaviour)

Question 28

BG dysfunction pathological manifestations

Answer 28

motor abnormalities impaired memory formation attention deficits affective disorders sleep disturbances

Question 29

PD

Answer 29

loss of DA neurons in substantia nigra pars compacta causes tremor, rigidity, bradykinesia and sleep disturbances (non-motor symptom)

Question 30

what is parkinsonism

Answer 30

induced oscillations resonate across BG networks with focal entrainment of STN, GPe and SNr

Question 31

regions involved in action selection

Answer 31

vertebrate basal ganglia arthopod central complex

Question 32

central complex direct pathway

Answer 32

(D1) pb/fb mEB gall dEB/LAL LAL

Question 33

what are EB ring neurons involved in

Answer 33

feature detection

Question 34

role of EB layers and hemisphere divisions

Answer 34

reciprocal inhibtion of networks

Question 35

selection and switching in EB

Answer 35

R-neuron circuitry mediate salience detection by winner take all functionality, selection of only one active module/wedge. It allows selection between activity states (strongest signal wins)

Question 36

maintenance in EB

Answer 36

lateral inhibition can maintain selected activity after input changes

Question 37

parkinsonism in drosophila

Answer 37

loss of DA-EB-LAL pathway is conserved

Question 38

how is action selection achieved

Answer 38

competing activity of direct and indirect pathway in BG neural activity of EB ring neurons