Electrocytes: Presence of Aluminium In Weakly Electric Fish (Rajidae) From Bahía Blanca.

BARRERA F.; SCHMITD, G.,; PRADO FIGUEROA, M.

CELLULAR AND MOLECULAR NEUROBIOLOGY.

SPRINGER/PLENUM PUBLISHERS

Lugar: New York; Año: 2001 vol. 21 p. 126 - 126

0272-4340

Electric organs of weakly electric fish Psammobatis extent (Rajidae) derive from myotomes of the caudal region and consist of macroscopic cells ?electrocytes- stacked along the antero-posterior axis. Electrocytes are highly polarized cells, semicircular in shape, with a anterior concave face receiving innervations from electromotor neurons of the spinal cord and a posterior, convex, non-innervated face that show numerous invaginations. Adult female P. extenta fish were caught wear the coast of Bahia Blanca, Argentina, and transported to the laboratory. Fresh electric organ segments were fixed in 2% glutaraldehyde in 0.05 M phosphate buffer, pH 7.2 for two hours at 4°C. The tissue was washed overnight with distilled water, dehydrated with acetone, dried and was subsequently coated with gold. The tissue was finally oriented for observation by SEM, and tested for content of cations with the aid of energy-dispersive spectra X-ray microanalysis by EDA. On non-innervated plasma membranes of electrocytes, energy-dispersive spectra show peaks localized at energy lines characteristic for Cu2+, Zn2+ and Al3+. Picture written with energy lines of the X-ray spectra have different concentration, location and more of distribution for thee cations. In electrocytes of P. extent from San Matias Gulf, Argentina, no aluminum was found.