Parvalbumin-immunoreactive neurons make inhibitory synapses on pyramidal cells in the human amygdala: a light and electron microscopic study.
In the present study we investigate the inhibitory circuitries that regulate the neuronal activity in the lateral and basal nuclei, which are the main sensory input regions of the amygdala. Axon terminals immunoreactive for parvalbumin, a calcium-binding protein known to colocalize with GABA, were examined in these regions with electron microscopy, and their postsynaptic targets were identified and characterized. In the lateral nucleus, parvalbumin-immunoreactive (PV-ir) axons formed terminal rows which made symmetric synaptic contacts on the axon initial segments of the pyramidal cells. In the basal nucleus, pericellular baskets of PV-ir fibers established symmetric synapses on pyramidal cell somata and proximal dendrites. Our data suggest that PV-ir neurons play a crucial inhibitory role in the control of pyramidal cell activity in the human amygdala.
Department of Neurology, University of Kuopio, Finland.
H
H
Sorvari
R
R
Miettinen
H
H
Soininen
A
A
Pitkänen
D000328:Adult; D000368:Aged; D000679:Amygdala / Q000502:physiology* / Q000648:ultrastructure; D006801:Humans; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D009474:Neurons / Q000502:physiology* / Q000648:ultrastructure; D010320:Parvalbumins / Q000502:physiology*; D017729:Presynaptic Terminals / Q000502:physiology / Q000648:ultrastructure; D017966:Pyramidal Cells / Q000502:physiology* / Q000648:ultrastructure; D013569:Synapses / Q000378:metabolism* / Q000648:ultrastructure
D010320:Parvalbumins