NSCI 324* Systems Neuroscience Doug Munoz Centre for Neuroscience Studies Botterell Hall, room 226...

NSCI 324*Systems Neuroscience

Doug MunozCentre for Neuroscience StudiesBotterell Hall, room 226x32111doug.munoz@queensu.ca

Tutorial: Monday Jan 23, 2012 10:30amBotterell B147TA: Jay Jantz (j.jantz@queensu.ca)

NSCI 324*Systems Neuroscience

Vision and Oculomotor Control (Dr. Munoz)January 10 The retina January 13 Central Visual PathwaysJanuary 16 Dr. Munoz Tutorial: January 16 Higher Visual functions January 17 Oculomotor System I. Basic organization January 20 Oculomotor System II. Vestibulo-ocular reflexJanuary 23 Dr. Munoz tutorial:January 23 Oculomotor System III. SaccadesJanuary 24 Basal Ganglia for cognitive and motor controlJanuary 27 review of Dr. Munoz lecture materialJanuary 30 Dr. Munoz exam in tutorial period

Oculomotor system II.VOR (vestibulo-ocular reflex)

Properties of MotoneuronsFi

ring

Freq

uenc

y

Eye Position (E)

Firin

g Fr

eque

ncy

Eye Velocity (E)

Extraocular Muscle Motoneurons

carry eye position and eye velocity

final common path for all eye movements

integrator located in reticular formation and vestibular complex of brainstem part of final common path

“Neural integrator” integrates E command to produce E command

muscleMNE + E

E

+

E +

Vestibulo-ocular Reflex

Vestibulo-Ocular Reflex

CNS

H E

H (-1) = E

Semicircular canals3 semicircular canals (horizontal, anterior, posterior) on each side of headThe canals are orthogonal to each other to represent complete 3-d rotations

Vestibulo-ocular Reflex

Hea

d m

o tio

n

nose

LR

MR

LR

MR

Horizontal canal

VestibularNucleus

AbducensNucleus

OculomotorNucleus

LR = lateral rectusMR = medial rectus

midline

(midbrain) (pons) (pons-medulla)

Horizontal VOR

Vestibular hair cell and afferent response

Hair cell (generator potential)

Primary vestibular afferent(action potentials to cns via 8th nerve)

Opponent processing: afferent has resting discharge and can therefore signal both directions of head motion via increase or decrease in activity

Hea

d m

o tio

n

nose

LR

MR

LR

MR

Horizontal canal

VestibularNucleus

AbducensNucleus

OculomotorNucleus

LR = lateral rectusMR = medial rectus

midline

(midbrain) (pons) (pons-medulla)

(-)

Horizontal VOR

Hea

d m

o tio

n

nose

LR

MR

LR

MR

Horizontal canal

VestibularNucleus

AbducensNucleus

OculomotorNucleus

LR = lateral rectusMR = medial rectus

midline

(midbrain) (pons) (pons-medulla)

Horizontal VOR

Hea

d m

o tio

n

nose

LR

MR

LR

MR

Horizontal canal

VestibularNucleus

AbducensNucleus

OculomotorNucleus

LR = lateral rectusMR = medial rectus

midline

(midbrain) (pons) (pons-medulla)

Horizontal VOR

Vestibulo-ocular Reflex

Canals organized into 3 orthogonal planes

Muscles organized into 3 orthogonal pairs

3-D organization of VOR