GABA-ergic and substance P-ergic double-innervation to noradrenergic neurons in the rat locus coeruleus.
Synaptic contacts between noradrenaline (NA) neurons and GABA (gamma-aminobutyric acid) afferents and/or substance P (SP) afferents in the locus coeruleus (LC) were examined by a combination of immunoelectron microscopic mirror method and double-immunostaining method. For visualization of NA and GABA, we used antibodies against NA and GABA synthesizing enzymes, i.e., tyrosine hydroxylase (TH) and glutamic acid decarboxylase (GAD). GAD-immunoreactive (IR) and SP-IR axon terminals often made synaptic contacts with NA neurons, respectively. Furthermore, we identified that a single NA neuron simultaneously receives synaptic inputs from GAD-IR and SP-IR afferents. These NA neurons made symmetrical synaptic contacts with GAD-IR axon terminals and asymmetrical contacts with SP-IR axon terminals. This suggests that central NA neuronal mechanisms are affected by GABA and SP neurons in a different manner.
Tamiya
R
R
First Department of Anatomy, Osaka City University Medical School, Japan.
Inoue
K
K
Takagi
H
H
D000818:Animals; D005968:Glutamate Decarboxylase / Q000378:metabolism; D008125:Locus Coeruleus / Q000737:chemistry*; D008297:Male; D009638:Norepinephrine / Q000032:analysis*; D051381:Rats; D017208:Rats, Wistar; D013373:Substance P / Q000032:analysis* / Q000276:immunology; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000032:analysis* / Q000276:immunology
D013373:Substance P; D005680:gamma-Aminobutyric Acid; D014446:Tyrosine 3-Monooxygenase; D005968:Glutamate Decarboxylase; D009638:Norepinephrine