Abstract
1. Simultaneous measurements of the receptor potential and the light-induced mitochondrial activation were performed in white-eyed blowflies Calliphora vicina, mutant chalky, and Lucilia cuprina, mutants w(F) and w'nss. The intensity dependence and the temporal dynamics were investigated.
2. The characteristic curve of the light-induced mitochondrial activation vs. log intensity has an S-like shape, which is much steeper than the characteristic curve of the receptor potential (the V/log I curve). The threshold intensity of mitochondrial activation elicits about a half-maximal receptor potential, while mitochondrial activation and photoreceptor potential saturate at about the same intensity.
3. The time course of the mitochondrial activation induced by a light flash, i.e. the pulse-response curve, is biphasic in both mutants with normal phototransduction properties, Calliphora chalky and Lucilia w(F); the shape is slightly species dependent.
4. In the phototransduction mutant Lucilia w'nss the step-responses of both the (bright) light-induced mitochondrial activation and receptor potential are quite different from the corresponding signals in Lucilia w(F). The striking resemblance of the step-response of the mitochondrial activation to its pulse-response indicates that mitochondrial activation and receptor potential are intimately linked.
Original language | English |
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Pages (from-to) | 305-312 |
Number of pages | 8 |
Journal | Journal of comparative physiology a-Neuroethology sensory neural and behavioral physiology |
Volume | 168 |
Issue number | 3 |
DOIs | |
Publication status | Published - 1991 |
Keywords
- BLOWFLY
- PHOTORECEPTOR
- RECEPTOR POTENTIAL
- MITOCHONDRIAL ACTIVATION
- CALCIUM
- PIGMENT MIGRATION
- RETINULAR CELLS
- LUCILIA-CUPRINA
- COMPOUND EYES
- CALCIUM-IONS
- FLY
- FLUORESCENCE
- INTACT
- SYSTEM
- SODIUM