01 August 2006

Dr. Paul Overton and Prof. Peter Redgrave win £305,000 grant from the BBSRC

Dr. Paul Overton and Prof. Peter Redgrave have won a £305,000 grant from the BBSRC (Biotechnology and Biological Sciences Research Council) for a project entitled "Short-latency auditory and somatosensory input to dopaminergic neurons." The research will run for three years and will support Veronique Coizet and fifty percent of a technical post. The abstract is below:

Short-latency auditory and somatosensory input to dopaminergic neurons

Dopaminergic neurons (DA) are activated at short latency by unexpected salient sensory stimuli in a range of modalities. Current theories suggest that the signal conveyed by DA neurons exclusively concerns reward, or that it has a broader remit, telling the forebrain that something salient has happened without telling it what it is. An important strategy for decoding the signal is to identify and then elucidate the perceptual properties of the sensory pathways providing input to DA neurons. Visual information is relayed to DA neurons via a subcortical structure, the superior colliculus (SC), more in keeping with the 'salience' than the 'reward' theory, since the SC can signal that something has occurred but is perceptually primitive. However, our knowledge of the sensory control of DA neurons is still incomplete: in particular, we lack fundamental information about the sensory systems which provide auditory and somatosensory information. The overall objective of the present proposal will be to determine the source(s) of this information, using a unique combination of neuroanatomy, electrophysiology and electrochemistry. The overarching objective of determining the source(s) of auditory and somatosensory information can be broken down into three smaller issues, and the specific aims of the project will be to address these issues: 1. Does the SC relay auditory and/or somatosensory information to DA neurons?; 2. What other structures, if any, also provide auditory and/or somatosensory information to DA neurons? 3. Do responses in DA neurons to auditory and somatosensory stimuli lead to changes in the release of dopamine in the neostriatum? The proposed experiments will provide essential information required to assess the nature and quality of the perceptual information available to DA neurons. As a consequence, the functional role of the signal conveyed to the forebrain via the activation of these cells will become appreciably
clearer.