Dopaminergic axons directly make synapses with GABAergic neurons in the rat neostriatum.
We examined with an electron microscopic 'mirror technique' whether glutamic acid decarboxylase-immunoreactive (GAD-IR) neurons are in direct synaptic contact with tyrosine hydroxylase-immunoreactive (TH-IR) axons in the rat neostriatum. Three types of GAD-IR neurons were identified in the nucleus caudatus putamen based upon their size and ultrastructural characteristics. These were medium spiny, medium aspiny and large cells. All types of GAD-IR neurons made synaptic contact with TH-IR axonal boutons at least on perikarya and proximal dendrites. This provides ultrastructural evidence for catecholaminergic, presumably, nigrostriatal dopaminergic inputs to both long- and short-axon neurons most probably containing GABA.
D000818:Animals; D003342:Corpus Striatum / Q000033:anatomy & histology*; D004298:Dopamine / Q000502:physiology*; D004745:Enkephalins / Q000378:metabolism; D005968:Glutamate Decarboxylase / Q000378:metabolism; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013569:Synapses / Q000648:ultrastructure; D009435:Synaptic Transmission; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000502:physiology*
D004745:Enkephalins; D005680:gamma-Aminobutyric Acid; D014446:Tyrosine 3-Monooxygenase; D005968:Glutamate Decarboxylase; D004298:Dopamine