Meeting Abstract

P1.145  Saturday, Jan. 4 15:30  Investigations of segmental regeneration in Lumbriculus variegatus SUNSONG, R.C.*; MARTINEZ-ACOSTA, V.G.; Univ. of the Incarnate Word, San Antonio; Univ. of the Incarnate Word, San Antonio vgmartin@uiwtx.edu

Gradients in regenerative capacity in Lumbriculus variegatus are reminiscent of morphogenic gradients that are responsible for early patterning of vertebrate body axis. Multiple studies in our lab demonstrate the emergence of newly regenerated head is necessary for respecification of neural function along the anterior-posterior body axis. We hypothesize then that inhibition of head regeneration would severely hinder the overall regenerative process and lead to a reduction in the recovery of function. This hypothesis will be tested by measuring the effects of complete inhibition of head regeneration on the neural reorganization events that are hallmarks of neural regeneration in Lumbriculus. Recent studies in other invertebrate species have suggested that inhibition of head regeneration slows down wound formation causing breakdown of the regenerative process and that bioelectric gradients and signaling molecules produced from the wound tissue are necessary for successful regeneration. Reduction in head regeneration has recently been accomplished using voltage-gated ion channel blockers (nicardipine, tricaine), protease inhibitors (AEBSF), protein-kinase inhibitors (Sphingosine, Staurosporine, and PP1/AGL1872), and gap junctional protein blockers (heptanol, hexanol). Using agents such as these we will inhibit head regeneration, and original worm fragments will be subsequently tested for the presence of axial reorganization responses including, changes in giant fiber diameter, changes in giant fiber conduction velocity, changes in reflex behavior, as well as changes in expression of MP66, a molecular marker of neural regeneration in Lumbriculus.