title: Surface temperature change, cortical evoked potential and pain behavior elicited by CO2 lasers.
abstract: The performance of a self-designed CO2 laser stimulator, TL#2, was evaluated against a commercial product, model DE20XL of the Direct Energy Inc. (Irvine). The major items evaluated were the temperature change of the irradiated surface and the electrophysiological and behavior changes in the rat elicited by single laser pulse irradiation. Single shots of TL#2 produced a profile of surface temperature change similar to those of the DE20XL, as quantified by their maximal temperature change, rate of rise (half time to maximum) and rate of temperature drop. TL#2 and DE20XL elicited the same pain behaviors and the same pattern of cortical evoked potential in awake, behaving rats. TL#2 differed from the DE20XL in its laser beam shape and focal depth. The cross sectional energy profile of the TL#2 was a Gaussian shape, i.e., most intense at its center point, whereas that of the DE20XL with the FL20XL attachment had a shape of an inverted Gaussian, i.e., most intense in the periphery. Consequently, the peak energy of the center of the TL#2 laser beam grows rapidly with an increase in the pulse intensity. Caution must be taken not to use this machine at high intensity or for long duration less permanent damage should be produced on tested animal or human subject. In summary, TL#2 when used properly, should be a useful tool in the study of pain mechanism.
authors.affiliation: Department of Zoology, National Taiwan University, R.O.C.
authors.forename: C T
authors.initials: CT
authors.lastname: Yen
authors.forename: C H
authors.initials: CH
authors.lastname: Huang
authors.forename: S E
authors.initials: SE
authors.lastname: Fu
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000502:physiology / Q000528:radiation effects*; D002245:Carbon Dioxide; D002540:Cerebral Cortex / Q000502:physiology / Q000528:radiation effects*; D004195:Disease Models, Animal; D004867:Equipment Design; D005071:Evoked Potentials / Q000528:radiation effects; D007834:Lasers; D009619:Nociceptors / Q000502:physiology / Q000528:radiation effects*; D010146:Pain / Q000209:etiology*; D051381:Rats; D013623:Tail; D013696:Temperature; D013997:Time Factors
chemical_list: D002245:Carbon Dioxide