ENZYMATIC TREATMENT OF THE CONNECTIVE TISSUE THAT COVER THE NERVOUS SYSTEM OF Spodoptera frugiperda

ARENA ME; POPICH S; PLANAS L; RIOBO IP; NICOLA SIRI L; BARDON A

BIOCELL

INCA

Lugar: Mendoza; Año: 2008 vol. 32 p. 95 - 95

0327-9545

The study of insects nervous system is an interesting way to regulate insect feeding behavior. The nerve stimulation is transmitted by electrical impulses that generate a membrane potential, inducing biological stimuli, such as appetite. In order to measure changes in the nervous system generated for different agents, we established the steps necessary to measure membrane potential in the nervous system of S. frugiperda, an important corn pest in Argentina. The central nervous system of insects is covered by a transparent layer of dense connective tissue which provides mechanical resistance to penetration. To penetrate the neural ganglia we manufacture microelectrods with the proper diameter. In order to disgregate the conective tisuue, we conducted various tests documenting the enzymatic action as a function of time: Test 1) colagenase (0.5%); 2) colagenase (5%), 3) mixing colagenase (0.6%) and protease (0.06%). The tests were carried out for 10 min, photographing the enzymatic action at 1 min intervals. Treatment with colagenase (5%) resulted aggressive for nervous tissue and disintegrated the connective tissue but also the neural ganglion, fact that was assessed by observation of single neurons which showed a structural discontinuity. Treatments 1 and 3 allowed the penetration of microelectrods inside neuronal ganglia. This is the first report on the investigation of electrophysiological responses to stimuli in S. frugiperda.