Abstract
Intracellular recordings were made from rat dorsal raphe neurons in vitro. Baclofen (30 μM) and 5-carboxamidotryptamine (5-CT, 300 nM to 1 μM) hyperpolarized these neurons by 10 and 13 mV, respectively. Depolarizing synaptic potentials (DSPs) were evoked by single shocks: baclofen reduced the amplitude of the DSP by 81%, but 5-CT reduced it by only 23%. The somatic response to iontophoretically applied glutamate pulses was reduced by 12% by baclofen, and 23% by 5-CT. In slices from rats pretreated with intracerebroventricular pertussis toxin (PTX), the ability of baclofen to reduce the DSP was almost unchanged, although the hyperpolarizing action of baclofen, and both actions of 5-CT were virtually eliminated. We conclude that it is possible to distinguish the pre- and postsynaptic actions of baclofen with PTX, and that the actions of 5-CT are both blocked.
Original language | English (US) |
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Pages (from-to) | 300-306 |
Number of pages | 7 |
Journal | Neuroscience Letters |
Volume | 93 |
Issue number | 2-3 |
DOIs | |
State | Published - Nov 11 1988 |
Keywords
- Baclofen
- Pertussis toxin
- Presynaptic inhibition
- Rat dorsal raphe nucleus
- Serotonin
- γ-Aminobutyric acid
ASJC Scopus subject areas
- General Neuroscience