Abstract
Effects of tetrahydroberberine (THB) on dopamine (DA)-induced response have been investigated in single pyramidal neurons freshly dissociated from CA1 area of the hippocampus using the nystatin perforated patch-clamp, whole-cell recording technique under voltage-clamp configuration. At a holding potential (V(H)) of -20 mV, DA-induced responses included a transient outward current, a slow inward current and a combination of the two. The outward current had a reversal potential of -83.5 ± 8.0 mV which was close to K+ equilibrium potential and was sensitive to TEA, suggesting that this outward current was carried by K+. Application of THB reversibly suppressed three type responses induced by DA with different degrees of inhibitory ratio, THB inhibited the DA-induced outward current in a concentration-dependent manner with an IC50 of 13 μM. The maximal value of the concentration-response curve for DA-induced outward current was suppressed by THB, suggesting a non-competitive inhibition. The results support the hypothesis that THB acts as a novel dopaminergic system antagonist. Furthermore, THB inhibits the DA-induced K+ current non-competitively in single dissociated cells, implying that THB may exhibit other pharmacological action on the central nervous system.
Original language | English (US) |
---|---|
Pages (from-to) | 155-158 |
Number of pages | 4 |
Journal | Neuroscience Letters |
Volume | 207 |
Issue number | 3 |
DOIs | |
State | Published - Apr 5 1996 |
Externally published | Yes |
Keywords
- Dissociated neurons
- Dopamine
- K current
- Patch-clamp
- Rat hippocampus
- Tetrahydroberberine
ASJC Scopus subject areas
- General Neuroscience