ISSN:
1432-1106
Keywords:
Neostriatum
;
Neostriatal slices
;
Ca++-activated potassium conductance
;
Ca++-blockers
;
TEA
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary The Ca++-dependence of the repetitive firing of neostriatal neurons was studied in an in vitro slice preparation of the rat neostriatum. Neuronal firing was evoked by injecting depolarizing currents of 100–200 ms duration. In normal conditions, the mode of firing was tonic and showed very little adaptation. The frequency-current relation was linear over a wide range of frequencies. The repetitive firing was first enhanced and later suppressed by Co++, Mn++ and Cd++. These effects on the repetitive firing by the Ca++-channel blockers paralleled the suppression of the slow afterhyperpolarizing potential. The lowering (0.2 mM) of Ca++ had similar effects. In the presence of TEA (up to 10 mM), the cell fired both Na+ and Ca+ action potentials. The results suggest that, as in other CNS neurons of the vertebrate, in neostriatal neurons the slow afterhyperpolarizing potential (AHP) is due to a Ca++-activated K+-conductance, and that the AHP plays a crucial role in the repetitive firing of these neurons.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00248539
