Modelling cognitive symptoms of schizophrenia in developmental vitamin D-deficient rats

On Wednesday 06 July 2011, Dr Tom Burne, Adjunct Senior Research Fellow with the Queensland Centre for Mental Health Research and the Queensland Brain Institute at The University of Queensland, will speak on the subject of modelling the cognitive symptoms of schizophrenia in developmental vitamin D-deficient rats.

Schizophrenia is a complex disorder characterized by hallucinations and delusions (positive symptoms) as well as impairments of cognitive symptoms, such as memory and attentional processing. Neurocognitive measures have been repeatedly found to have greater predictive value for social and occupational recovery than positive symptoms, indicating a greater likelihood of better patient outcomes.
 
Epidemiological evidence suggests that vitamin D may be a potential risk factor for schizophrenia, and we have shown that such a hypothesis is biologically plausible using a developmental vitamin D (DVD)-deficient rat model. We have used a range of tasks to examine cognitive processes, including sustained attention, behavioural inhibition and motivation, in both control and DVD-deficient rats. We have shown that DVD-deficient rats demonstrated mildly enhanced impulsivity but were normal on all measures of vigilance when assessed on a serial reaction time task. By contrast, they showed a lack of inhibition on non-signal trials of a continuous performance task; this was observed immediately and persisted throughout testing.
 
However, when we explicitly assessed behavioural inhibition using a differential reinforcement task, there was no effect of diet on performance. Instead, DVD-deficient rats had a significant reduction in response rate on the progressive ratio task, which indicates reduced levels of motivation to perform the task in these animals. We have previously shown that the dopaminergic and glutamatergic systems are altered in DVD-deficient rats and, given the role of these systems in motivation and reward, these may underlie the cognitive deficits described. Thus, the DVD-deficient rat model is characterised by a phenotype reminiscent of both positive and negative symptoms of schizophrenia. Collectively, these results suggest that DVD-deficient rats may also have specific impairments in cognitive function informative in terms of modelling the cognitive deficits seen in schizophrenia.
 
DETAILS:
 
Date: Wednesday 06 July 2011
Time: 12:00 - 1:00PM
Location: Level 7 Auditorium, QBI Building (#79), St.Lucia Campus
Seminars will be followed by a sandwich lunch for all attendees.
 
For a list of upcoming seminars at QBI, go to http://www.qbi.uq.edu.au/neuroscience-seminars

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