Subject outline: PL379
Sensory Neurobiology [Science]
Sign-Up Sheet for Weekly Presentations:
Assessment and Suggested Assignment Topics:
Go to Spread Sheet of Final Results:
Subject Details
Subject Areas:
* Trigger features
* Retinal plasticity
* Visual cortical plasticity
* Cerebellum
* Cochlea
* Neural Time: From Bacterial Chemotaxis to Jet-lag
* Functional MRI: Introspection Rules, OK?
* Interhemispheric Switching and Bipolar Disorder
* Hemispheric Asymmetries and Mood
Goal: To examine the structure, development and organization of sensory pathways as one approach to understanding the brain.
Details: This subject is taught by the senior research staff of
the Vision,Touch and Hearing Research Centre, and it provides an in-depth
understanding of select topics in sensory neurobiology, based on (1) lectures
by the specialist staff and (2) the analysis and presentation of recent
research papers by the students. The course highlights common themes in
the neuronal processing of sensory information, as well as training the
students to critically review original research papers. In 1999 there will
be an emphasis on a new series of discoveries in human and animal brains
that suggest a special role for the monoaminergic brainstem neuromodulatory
circuits in the phenomenon of interhemispheric switching and theri role
in mood and mood disorder.
This Semester 2 subject is designed to be free-standing of the Semester
1 subject PL391 Neurobiology and the Semester 2 subject PL376 Cellular
Neurobiology, although students who take combinations of these courses
will benefit from their synergy. The recommended prerequisite subjects
(non-compulsory) for PL379 are PL292 or AN232, and the recommended companion
subject (non-compulsory) is AN304.
Credit: #6, 1L 2C, requiring an average of 3 hours of private study
per week.
Outline: Prior to the Week 1 lecture on ëTrigger featuresí,
Prof Pettigrew will outline the course format and explain the assessment
procedures. The students will be given the list of topics to be covered
in the seminars from Weeks 2-12, and they will be assigned to a given topic
during the Week 1 seminar (in two's or three's if required), taking into
account their preferences for topics.
Because of the large number of students enrolled for the course, it
may not be possible for every student to maje an oral presentation. In
this case, the group will divided into teams to assist in preparation of
the material and to decide who presents. The remainder of the Week
1 seminar will be devoted to a tour of the research facilities at the Vision,
Touch and Hearing Research Centre, depending on student numbers.
In Weeks 2-12, the staff member giving the lecture on the Tuesday will
choose 1 or 2 key research papers that are related to the lecture topic,
for presentation by 1-3 students during the seminar on the Thursday. These
assigned papers are to be read in advance by all students in the course.
In addition, the staff member will provide 2-4 background references to
aid the students in their presentations. The students should outline the
background to the research paper, the scientific problem tackled by the
paper, the methods for doing this, the significance of the results and
their limitations, and the outstanding questions that remain for future
studies.
The lecturer will either provide each student with 4 transparency sheets
for making their own overhead transparencies, or the lecturer will photocopy
up to 4 pages of the student's notes and diagrams onto transparency sheets.
Assessment: 50% Examination. There will be 2 x 1-hour open-book
take-home written examinations, one in mid-semester and one at the end
of Semester 2, which will cover material in both the lectures and the assigned
research papers.
30% Essay. Each student will write a 2,000-word essay on a topic
in sensory neurobiology, to be chosen either from a list provided by the
lecturers, or by the student in consultation with one of the lecturers
or other senior staff at VTHRC. The essay is due at the end of the seminar
of Week 10 (Thursday October 9).
10% Seminar Presentation. The presentations are not graded (although
the staff do keep their eyes open for excellent students who might be suitable
for honours projects). If it is not possible for the student to give an
oral presentation, that student will be given credit for assisting the
preparation of the team member who does, as well as for attending and supporting
the presentation.
10% Seminar Attendance and Participation.
Coordinator: Professor Jack Pettigrew Rm A202, Ritchie Bldg Ext 53842
Lecturers: Assoc. Prof. Shaun Collin Rm A204 Ritchie Bldg Ext.54066
Dr Jim Pickles Rm C206 Ritchie Bldg Ext 54125
Dr Steve Miller Rm A205 Ext 53929
Timetable:
Lecture: Tuesday 5-6 pm
Seminar: Thursday 4-6 pm
Lecture and seminar outlines
Lecture 1,2 Introduction and Trigger features:- Prof Jack Pettigrew
The format of the course will be outlined and assessment procedures
explained. Students will be assigned topics to be covered in the student
seminars. Certain neurons in the retina and visual corteices are sensitive
to particular attributes of the stimuli, such as orientation, the direction
and speed of movement, etc. The properties and functional significance
of neurons with such ìtrigger featuresî will be discussed.
Lecture 3 Retinal Plasticity:- Assoc. Prof. Shaun Collin
The properties of retinal photoreceptors and retinal neurons show astonishing
diversity in their adaptation to different visual niches. This is particularly
evident in fish, the most diverse group of vertebrates. Examples illustrating
the diversity of retinal adaptations will be taken from a variety of fish
occupying different habitats, from colourful shallow-water tropics to the
deep sea.
Lecture 4 Visual Cortical Plasticity:Tuned Trigger Features:- Prof.
Jack Pettigrew
Early development of visual cortex is characterised by extreme
plasticity. During the ìcritical periodî single neurons appear
to become tuned to trigger features in the environment. The gating
mechanism that turns on plasticity early in life and turns it off again
later is still debated, but there a number of possibilities such as the
neuromodulatory cholinergic and adrenergic systems.
Lecture 5 Comparative Physiology of Binocular Vision:- Prof. Jack
Pettigrew
The owl and the pussy cat have each evolved binocular neurons that
subserve stereopsis, but the underlying circuitry is quite different in
the avian brain compared with the mammalian brain. This lecture will introduce
steropsis, a sensory ability found in 90% of the population and show how
a comparison of owl and cat stereopsis illuminates the neural basis of
this complex ability.
Lecture 6 Cerebellum: Prof. Jack Pettigrew.
The beautifully-ordered structure of the cerebellum has attracted
many students and many theories of its function. Currrent theories of cerebellar
function will be presented, including important new data on anti-Hebbian
plasticity in cerebellum of electric fish Procedural (cerebellar)
memory will be contrasted with declarative memeory. As well as its role
in movement and sensory processing, the cerebellumís role in higher
level cognitive functions and mood will be discussed.
Lecture 7,8 Cochlea Dr Jim Pickles
The development, function and repair of cochlear hair cells is
discussed in relation to the mechanical input of the cochlea and growth
factors affecting the cells.
Lecture 9 Circadian clocks:- Prof. Jack Pettigrew
This week will deal with recent advances in the molecular biology of
circadian clocks, including the genes per, tim, clock, cry, mbal
and tau. The class will also wrestle with the following paradox:
- clocks must have a stable periodicity that is not perturbed by external
factors such as light and temperature (A Drosophila in a fridge
keeps very good time despite its lower temperature). Nevertheless, clocks
have to exquisitely sensitive to these same external cues so that phase
shifts can be brought about to keep the clock in synch. with the environment.
A solution to the paradox will be offered from work on the "zeitnehmer".
Lecture 10 Time: From Bacterial Chemotaxis to Jet-lag.:- Prof. Jack
Pettigrew
Much more is known about the representation of space by the brain
than the representation of time.
Lecture 11 Functional MRI: Introspection Rules OK?:- Prof. Jack Pettigrew.
A revolution in neuroscience is challenging the century-old bias
against the use of introspetion in brain studies. fMRI allows the non-invasive
imaging of the functional areas of a living human brain. Introspection
can thus be objectively checked, within the limits of sensitivity of the
technique. The basis of technique will be explained. Some recent examples
from studies of the visual pathways and the motor systems will be used
for illustration.
Lecture 12 Interhemispheric Switching and Bipolar Disorder ? Prof Jack
Pettigrew
Recent work implicates a slowed interhemispheric switch in the
aetiology of bipolar (manic-depressive) disorder. This week will build
on the previous weekís treatment of hemispheric asymmetries and
introduce the idea of a bistable oscillator in the brainstem that switches
activation between complementary functions in each hemisphere. Since slow
switches are ìstickyî, the class will finish with a consideration
of the effects for bipolar disorder of the switch becoming ìstuckî
on one hemisphere.
Lecture 13 Hemispheric Asymmetries and Mood:- Dr. Steven Miller
Adundant evidence from lesion studies, trans-cranial magnetic
stimulation and scanning studies (fMRI and PET) suggest that hemispheric
asymmetry is linked to mood, with left hemisphere activation associated
with elevated mood and right hemisphere activation associated with depressed
mood. This work will be reviewed and placed in the context of Ramachandranís
formulation of the contrasting cogntive styles of the two hemisperes and
the interhemispheric switching hypothesis of mood and mood disorder.