Korean J Physiol Pharmacol.  2005 Oct;9(5):255-262.

5-Hydroxytryptamine Inhibits Glutamatergic Synaptic Transmission in Rat Corticostriatal Brain Slice

• Cho HS
• Choi SJ
• Kim KJ
• Lee HH
• Kim SY
• Cho YJ
• Sung KW

Abstract

Striatum is involved in the control of movement and habitual memory. It receives glutamatergic input from wide area of the cerebral cortex as well as an extensive serotonergic (5-hydroxytryptamine, 5-HT) input from the raphe nuclei. In our study, the effects of 5-HT on synaptic transmission were studied in the rat corticostriatal brain slice using in vitro whole-cell recording technique. 5-HT inhibited the amplitude as well as frequency of spontaneous excitatory postsynaptic currents (sEPSC) significantly, and neither gamma-aminobutyric acid (GABA) A receptor antagonist bicuculline (BIC), nor N-methyl-D-aspartate (NMDA) receptor antagonist, DL-2-amino-5-phosphonovaleric acid (AP-V) could block the effect of 5-HT. In the presence non-NMDA receptor antagonist, 2, 3-dioxo-6-nitro-1, 2, 3, 4-tetrahydrobenxo[f] quinoxaline-7-sulfonamide (NBQX), the inhibitory effect of 5-HT was blocked. We also figured out that 5-HT change the channel kinetics of the sEPSC. There was a significant increase in the rise time during the 5-HT application. Our results suggest that 5-HT has an effect on both pre- and postsynaptic site with decreasing neurotransmitter release probability of glutamate and decreasing the sensitivity to glutamate by increasing the rise time of non-NMDA receptor mediated synaptic transmission in the corticostriatal synapses.

Keyword

Striatum; 5-Hydoxytrptamine; Spontaneous EPSC; Synaptic transmission

MeSH Terms

Animals
Bicuculline
Brain*
Cerebral Cortex
Excitatory Postsynaptic Potentials
gamma-Aminobutyric Acid
Glutamic Acid
Kinetics
Memory
N-Methylaspartate
Neurotransmitter Agents
Patch-Clamp Techniques
Raphe Nuclei
Rats*
Serotonin*
Synapses
Synaptic Transmission*
Bicuculline
Glutamic Acid
N-Methylaspartate
Neurotransmitter Agents
Serotonin
gamma-Aminobutyric Acid