The purpose ofthis project is to develop a rodent model for tactile defensiveness. This is to complement our studies of auditory sensorimotor gating. The proposed project would provide an important extension the rat model to include tactile as well as auditory defensiveness either of which can be affected in sensory modulation disorder. In fact, tactile defensiveness appears to be more common. Auditory gating was approached first in the current line of research because auditory pre-pulse inhibition (PPI) is a well-established technique with a rich literature base of neurobehavioral information. Tactile gating can be approached in a similar manner, but much of the groundwork needs to be done. We have conducted the basic characterization of the pre-pulse inhibition paradigm in the tactile mode determining the critical timing of the stimuli and air puff intensity to elicit reliable inhibition of the motor startle to repeated tactile stimuli. After the model was developed, we used it to determine the role of glutaminergic neurotransmission in the neural basis of the response. This tactile defensiveness model will provide an important complement to the auditory defensiveness model already being studied.

Although people with sensory defensiveness may show enhanced response in either the auditory or tactile mode (or both), it is not clear how the neural substrate for defensiveness in these modes may be similar or different. The dual characterization of tactile as well as auditory defensiveness in the rat model will make more complete our understanding of the neural systems underlying sensory defensiveness and better treatments for this syndrome.

Childhood Disablity Update 2005 - Conference Abstracts.Pediatric Oncall [serial online] 2006 [cited 15 January 2006(Supplement 1)];3. Available from:
http://www.pediatriconcall.com/fordoctor/Conference_abstracts/
Tactile_Defensiveness.asp