ISSN:
1432-0878
Keywords:
Calbindin
;
Cytochrome oxidase
;
Electrosensory lateral-line lobe
;
Spherical cells
;
Torus semicircularis
;
Apteronotus leptorhynchus, Eigenmannia virescens, Sternopygus macrurus (Teleostei)
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary Weakly electric fish (Gymnotiformes) emit quasi-sinusoidal electric organ discharges within speciesspecific frequency ranges. The electrosensory system is organized into 2 parallel pathways which convey either the amplitude or the timing of each electric organ discharge cycle. Two putative metabolic activity markers, calbindin D 28K and cytochrome c oxidase, and their relationship with the electrosensory nuclei of high- and low-frequency species were studied. Calbindin is found in the somata of the spherical neurons in the first-order electrosensory recipient nucleus, the electrosensory lateral-line lobe, and in layer VI of the midbrain's torus semicircularis, in Eigenmannia virescens, an intermediate-frequency species, and Apteronotus leptorhynchus, a high-frequency species. Calbindin immunoreactivity was completely absent in these nuclei in Sternopygus macrurus, a closely related, low-frequency species. Cytochrome c oxidase levels were inversely related to calbindin immunoreactivity since relatively high levels were observed in the electrosensory lateral-line lobe and torus semicircularis of S. macrurus but were absent in these nuclei in A. leptorhynchus. Our studies indicate that calbindin immunoreactivity is present in tonic, repetitively firing neurons with high frequencies.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00297487
Permalink
