ISSN:
1573-6830
Keywords:
cadmium
;
lead
;
voltage-activated currents
;
Ca currents
;
K currents
;
chronic exposure
;
Lymnaea stagnalis L.
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary 1. Voltage-activated ionic currents of three identified neurons ofLymnaea stagnalis L. were compared in control snails and in animals having been exposed to a cadmium- or lead-enriched environment for 2 weeks. We determined the presence, amplitude, and changes, if any, in the current-voltage characteristics of calcium and potassium currents in each of the three neurons from each of the three groups of animals. Finally, we have compared the effects of acute administration of Cd2+ or Pb2+ on neurons from control and chronically exposed animals. 2. Chronic exposure to cadmium resulted in a near doubling of the high voltage-activated calcium current. 3. No differences were found in the effects of acute application of Cd2+ or Pb2+ on neurons of pretreated and control animals. Cadmium was a potent blocker of the Ca current in either case, while lead caused only a 20% inhibition of the Ca current in neurons of both control and lead-exposed animals. 4. Potassium currents were affected in both Cd2+- and Pb2+-exposed animals. While the sustained outward current was not influenced noticeably, the fast K current was affected in different ways in different neurons. Some did not show this current in the controls but expressed it in neurons from the exposed animals. Other neurons showed the current in the controls and its depression in exposed animals. Acute application of cadmium did not modulate the K current, but lead enhanced the peak amplitude of the transient K current in neurons of both exposed and control snails.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02088683
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