Neuroimaging
Head: Dr. José N. Nobrega
Research work in this section is aimed at identifying specific brain
areas, neuroanatomical pathways and chemical mechanisms involved in neuropsychiatric
disorders. This is done through detailed post-mortem analyses of anatomically
preserved brains from animal models or human subjects. Currently three
major areas of research are being pursued.
Models of Depression
We are analyzing brain alterations in four different models of depression,
in particular the role of thyroid hormones and their receptors in brain.
Models currently under study involve reactivity to stress as well as genetic
models provided by collaborators from McMaster University and the University
of Maryland. These analyses are complemented by similar investigations
of the effects of various types of antidepressant interventions, including
sleep deprivation, on the same brain systems and pathways.
Brain analyses in these models have recently been expanded with the introduction
of cDNA microarray techniques for large-scale gene screening. This approach
has already produced very promising results in one the models and is now
being extended to the others.
Brain Dopamine and Movement
Disorders
In collaboration with investigators from Hanover, Germany, a long-term
project continues to build a comprehensive map of brain alterations in
a genetic model of paroxysmal dystonia. Recent findings include indications
of key alterations in metabotropic glutamate receptors in basal ganglia.
New funding has been obtained for this section's long-term work with
a model of tardive dyskinetic syndromes induced by long-term antipsychotic
treatment. In collaboration with clinical researchers from the Centre's
Schizophrenia Division, we are investigating the effects of antipsychotic
dose and mode of administration in this model, and new specific hypotheses
are being tested on atypical antipsychotics. The model has now been expanded
to the study of mice lacking specific types of dopamine receptors.
Brain Mechanisms of
Compulsive Drug-Taking
For the last few years, in collaboration with a group from São
Paulo, Brazil, we have been conducting a systematic investigation of brain
mechanisms underlying differential susceptibility to alcohol sensitization.
We have now completed a map of dopamine receptor changes in this model,
and have recently found unexpected evidence that specific types of glutamate
receptors play a role in resistance to alcohol sensitization.
In collaboration with Dr. D. Tomkins and R. Tyndale, a comprehensive
mapping of changes in the GABAa receptor system has been completed in
animals showing differential propensities to consume alcohol. New funding
for this work has now made it possible to extend these analyses to genetic
models of alcohol preference.
As illustrated, the Neuroimaging Section maintains an extensive and very
active network of research collaborations. A number of the projects listed
above were carried out in close collaboration with other research groups
at the Centre, at the University of Toronto, elsewhere in Canada (McMaster
University) and abroad (University of Maryland, University of São
Paulo and School of Veterinary Medicine, Hanover, Germany).
|
1-800-463-6273
