with biotinylated src peptides followed by streptavidin hrp conjugate male sprague dawley rats 150 200 g were used for all experiments rats were housed in pairs maintained on a 12 12 hour light dark cycle and allowed free access to food and water all experiments were conducted during 10 am and 5 pm peptide src40 49tat tsudapi 1 seq id no 2 or tat alone amino acid residues 1 11 of seq id no 2 was dissolved in sterilized saline peptide or saline was injected intravenously at a volume 1 ml kg into rat 39 s tail 45 minutes before behavioral testing injections were done under brief halothane anesthesia and rats were returned to the cages after injections the formalin test was performed as previously described liu et al european journal of pharmacology 408 2 143 152 2000 rats were placed in a plexiglass observation chamber for an initial 20 minutes to allow acclimatization to the testing environment formalin 2 5 was injected subcutaneously in a volume of 50 ml into the plantar aspect of the hind paw following injections rats were returned to the observation chamber and monitored for flinching behaviors lifting shaking and overt flinching with a ripple over the haunch and biting licking time two rats in adjacent chambers were observed at one time with observations occurring in alternate 2 minute bins recorded episodes were not corrected thus values represent about half of the total behaviors expressed fig7 a d show the effect of src40 49tat 0 1 pmol on 2 5 formalin induced flinching or biting licking behaviors peptides or saline controls were injected 45 minutes before behavioral testing fig7 b shows measurement of flinching behaviors observed within.