Central Neural Mechanisms Underlying The Effect Of Endocannabinoids On Body Weight
Funder
National Health and Medical Research Council
Funding Amount
$377,793.00
Summary
Obesity and its associated pathologies of cardiovascular and respiratory disease, stroke, predisposition to some cancers and infertility in women no longer needs to be justified as a major health issue in modern societies. In fact it is quickly becoming recognised as the major threat to world health. Recently, the anecdotal evidence for increased food intake, particularly the craving of high carbohydrate, high sugar foods, associated with the use of marijuana has been put into a therapeutic cont ....Obesity and its associated pathologies of cardiovascular and respiratory disease, stroke, predisposition to some cancers and infertility in women no longer needs to be justified as a major health issue in modern societies. In fact it is quickly becoming recognised as the major threat to world health. Recently, the anecdotal evidence for increased food intake, particularly the craving of high carbohydrate, high sugar foods, associated with the use of marijuana has been put into a therapeutic context. Specifically a cannabinoid receptor antagonist, rimonabant (currently undergoing trials as Accomplia) has become a central player in the race for an obesity therapy because of its effects in blocking the brain receptors that would normally respond to cannabinoid like compounds in the brain that tend to increase food intake. Despite the trials that are underway in Europe and the USA many of the central actions of the naturally occurring cannabinoids in the brain, the so-called endocannabinoids are very poorly understood. This series of experiments utilizing the best technologies available will address basic questions relating to the brain pathways involved and even the extent to which weight loss associated with the administration of these drugs to rats and presumably humans is dependent on the reduction of food intake or the burning of energy in a process called thermogenesis. These are essential pieces of information if this type of compound is to be considered as a serious contender in the search for an obesity therapyRead moreRead less
Standardisation Of Prepulse Inhibition Of The Startle Reflex For Pharmacological And Interspecies Comparisons
Funder
National Health and Medical Research Council
Funding Amount
$252,761.00
Summary
People and other animals startle when they here a sudden loud sound. How much one startles depends in part on how loud the sound is. The relationship between the loudness of the sound and the size of the startle resembles a ski slope. Each individual has a ski slope that differs from others; the beginning of the ski slope (threshold) occurs at a different loudness, the slope is a different steepness, and the height of the ski slope where the plateau occurs is different. There are genetic differe ....People and other animals startle when they here a sudden loud sound. How much one startles depends in part on how loud the sound is. The relationship between the loudness of the sound and the size of the startle resembles a ski slope. Each individual has a ski slope that differs from others; the beginning of the ski slope (threshold) occurs at a different loudness, the slope is a different steepness, and the height of the ski slope where the plateau occurs is different. There are genetic differences in ski slopes as well. The size of the startle reflex can also be reduced by preceding the startling sound with a quiet stimulus a few tens of milliseconds before the startling stimulus. This is known as prepulse inhibition of the startle reflex or PPI for short. There is much interest in PPI, because it differs in people with certain mental illnesses, such as schizophrenia or post-traumatic stress disorder, and certain neurological illnesses, such as Huntington's chorea. It is also affected by drugs, including stimulants, stress hormones, and cannabis. In almost all the hundreds of experiments on PPI the effect of the prepulse on the response to a startling stimulus is measured at only one startling stimulus loudness. This loudness can be at very different parts of the ski slope for different people or other animals: it may be in the steep slope for one person, well into the plateau for another, or even at the bottom of the ski slope below the threshold in others. The effect of PPI is very different depending on what part of the ski slope the loudness represents. A lack of consistent effects in the literature on PPI by drugs and genetics is explained by this difference. Experiments are planned that will investigate the effect of drugs that are similar to those that treat schizophrenia, stress hormones and cannabis on the effect of prepulses on the whole ski slope. This procedure will provide the consistency in results so far absent.Read moreRead less
My research is focused on understanding the aetiology of brain disorders. I am interested in the interaction of genetic and environmental factors in the development of these disorders. In particular, I will evaluate the validity of rodent models for schizophrenia and Alzheimer’s disease and investigate the therapeutic potential of the endocannabinoid system for both disorders and whether environmental enrichment (e.g. physical exercise) can have beneficial effects in these models.