MDMA ("Ecstasy") is a popular "dance party drug" that produces unique feelings of euphoria, enhanced communication and closeness to others. However MDMA may also have long-term toxic effects on the brain and has been linked to depression, anxiety and cognitive deficits. Our laboratory has an extensive program of research focused on MDMA and the related party drugs such as methamphetamine ("Ice") and GHB ("Fantasy"). This resaerch involves my colleagues Paul Callaghan, Petra van Nieuwenhuijzen, Murray Thompson, Glenn Hunt and Kong Li (Department of Pharmacology) and is currently funded by the NH&MRC.

Ongoing projects include the following:

• Examining long term changes in mood, behaviour and cognition caused by MDMA, methamphetamine and GHB.
• The effects of mixing MDMA, methamphetamine and GHB.
• The mechanisms underlying the unique social effects of MDMA and GHB with a particular interest in the neuropeptide oxytocin.
• The patterns of neural activation produced by party drugs, as determined by c-fos immunohistochemistry.
  

Cannabis is the most widely used illicit drug in the world, yet many of its effects are still quite mysterious. For many years my laboratory has examined various behavioural and neural effects of cannabis-like drugs (cannabinoids) including the "brain's own cannabis", a substance called anandamide. These experiments are currently being undertaken with my colleagues Dr Leonora Long, Dr Jonathon Arnold, Ljiljana Sokolic, Nathan Gunasekaran, Lauren Monds, and Garth Hargreaves and are funded by the ARC and NH&MRC.

Recent topics we have addressed include:

• Examining the effects of cannabinoids on cognitive function, with a particular emphasis on cognitive flexibility.
• Whether THC, the active component of cannabis, can be released from fat stores back into blood to cause "re-intoxication".
• Whether exposure to cannabinoids increases vulnerability to the effects of other drugs such as alcohol and cocaine.
• Effects of chronic cannabis exposure on brain protein expression, particularly in the hippocampus.
• Whether the adolescent brain is more vulnerable to adverse effects of cannabis.

Alcohol related problems are estimated to cost the Australian community more than $5 billion per year. With my colleague Garth Hasrgreaves I have undertaken research that looks at the nature and treatment of alcohol craving. This research talkes advantage of the the prodigious appetite that rats have for consuming standard off-the-shelf beers. This research has been funded by the Australian Brewers Foundation and the University of Sydney Sesqui Research Grant Scheme.

Recent experiments include the following:

• Comparison of beer intake in rats with intake of dilute ethanol solutions.
• Assessing the extent to which beer is consumed for intoxication versus calories.
• Identification of the possible neural substrates of alcohol craving and drugs that can be used to block alcohol craving.
• Assessment of whether and why adolescent rats are particularly prome to binge drinking.

Laboratory rats exposed to the odour of a natural predator (cat) show a strong anxiety response. This is despite the fact that they have never acutally met a cat before. This powerful innate anxiety response to cat odour in rats may be analogous to certain human anxiety states such as phobias. My research on this topic has been undertaken with Glenn Hunt, Paul Bayes and Lauren Staples and is currently funded by the Australian Research Council.

Ongoing projects include:

• Whether and how cat odour-induced anxiety is decreased by anxiolytic drugs such as benzodiazepines.
• Whether the odour-induced anxiety habituates with repeated exposure to the odour.
• Identification of brain activation produced by cat odour.
• Identification of the chemicals that cats secrete which cause the anxiety response in rodents.
  

Some researchers have claimed that rats may be as intelligent as humans if we assess their intelligence with odours rather than IQ tests! Yet most "cognitive" tests with rats employ auditory, visual or spatial stimuli rather than olfactory stimuli. To help remedy this situation Ljiljana Sokolic and I have implemented various olfactory-based tasks for testing learning and memory in rats (olfactory go/no-go discrimination, discrimination reversals, olfactory delayed nonmatching to sample, olfactory habituation/dishabituation).

Experiments include:

• Development of behavioural paradigms that allow the discrimination of odours and odour mixtures to be assessed.
• Mapping of olfactory bulb activation to individual odours, odour mixtures and biologically important odours such as predator odour.
• Demonstration of "olfactory learning set" in rats that is analogous to primate and human learning.
• Determination of the effects of benzodiazepines, cannabinoids and cholinergic drugs on olfactory memory.