Glutamate receptor stimulation induces a persistent rhythmicity of the GABAergic inputs to rat midbrain dopaminergic neurons.
The substantia nigra pars compacta and the ventral tegmental area are part of a complex network in the basal ganglia involved in behaviours as diverse as motor planning, generation of pleasure and drug addiction. Here we report that in the dopaminergic neurons of the rat ventral midbrain a brief coactivation of group I metabotropic and NMDA glutamate receptors may transform a temporally dispersed synaptic GABAergic input into a rhythmic pattern (range 4.5-22.5 Hz), probably through a mechanism involving electrotonic couplings. The plastic and long-lasting modification in the temporal code of the inhibitory synaptic activity induced by glutamate may be a key element in determining the function of midbrain dopaminergic neurons in both normal and pathological behaviour.
Berretta
N
N
Fondazione Santa Lucia IRCCS, Via Ardeatina 306, 00179 Rome, Italy. n.berretta@hsantalucia.it
Paolucci
E
E
Bernardi
G
G
Mercuri
N B
NB
D018750:6-Cyano-7-nitroquinoxaline-2,3-dione / Q000494:pharmacology; D000818:Animals; D001565:Benzoates / Q000494:pharmacology; D004298:Dopamine / Q000502:physiology; D004594:Electrophysiology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D017629:Gap Junctions / Q000502:physiology; D005998:Glycine / Q000031:analogs & derivatives* / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D009434:Neural Pathways / Q000502:physiology; D009474:Neurons / Q000502:physiology*; D010507:Periodicity; D051381:Rats; D017208:Rats, Wistar; D018094:Receptors, Metabotropic Glutamate / Q000502:physiology*; D016194:Receptors, N-Methyl-D-Aspartate / Q000502:physiology*; D012118:Resorcinols / Q000494:pharmacology; D013378:Substantia Nigra / Q000166:cytology / Q000502:physiology*; D005680:gamma-Aminobutyric Acid / Q000502:physiology*
D001565:Benzoates; D018691:Excitatory Amino Acid Antagonists; D018094:Receptors, Metabotropic Glutamate; D016194:Receptors, N-Methyl-D-Aspartate; D012118:Resorcinols; C104077:metabotropic glutamate receptor type 1; C079694:alpha-methyl-4-carboxyphenylglycine; D005680:gamma-Aminobutyric Acid; C079215:3,5-dihydroxyphenylglycine; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D005998:Glycine; D004298:Dopamine