PMID- 14755631
OWN - NLM
STAT- MEDLINE
DCOM- 20040507
LR  - 20071114
IS  - 0887-4476 (Print)
IS  - 0887-4476 (Linking)
VI  - 52
IP  - 1
DP  - 2004 Apr
TI  - Ultrastructural localization of Leu5-enkephalin immunoreactivity in mesocortical 
      neurons and their input terminals in rat ventral tegmental area.
PG  - 38-52
AB  - Enkephalin (ENK) immunoreactivity is widely distributed in the ventral tegmental 
      area (VTA), where endogenous ENK and dynorphin opioid peptides are known to have 
      opposing actions in reward, stress, cognition, and fear-related behaviors. Many 
      neurons in the VTA give rise to mesocortical projections terminating in the 
      medial prefrontal cortex (mPFC), and these projections have been implicated to 
      varying extents in all these functions. To determine whether there is a synaptic 
      basis for ENK and/or dynorphin modulation of cortically projecting neurons within 
      the VTA, we combined retrograde tract-tracing from the mPFC with dual 
      immunocytochemical-labeling electron microscopy in the rat VTA. The retrograde 
      tracer Fluorogold (FG) was microinjected into mPFC. At optimal survival periods, 
      sections through the VTA were processed for immunolabeling of anti-FG and a 
      Leu(5)-ENK antibody recognizing both ENK and dynorphin peptides. Over 26% of the 
      retrogradely labeled neuronal somatodendritic profiles (n = 177) were contacted 
      by ENK-immunoreactive axonal profiles including small axons and axon terminals. 
      The axon terminals varied in their subcellular distribution of ENK 
      immunoreactivity and also differed in forming either inhibitory-type (symmetric) 
      or excitatory-type (asymmetric) synapses. Many of the axonal profiles also were 
      apposed to FG-labeled somata or dendrites without forming recognizable synapses. 
      Approximately one-third of the mesocortical neuronal perikarya also showed 
      sparsely distributed somatodendritic ENK-immunoreactivity. Our results provide 
      ultrastructural evidence that ENK and possibly dynorphin in the rat VTA have 
      distributions consistent with involvement in diverse physiological actions 
      affecting the output of mesocortical neurons, some of which also contain one or 
      both peptides.
CI  - Copyright 2004 Wiley-Liss, Inc.
FAU - Garzon, Miguel
AU  - Garzon M
AD  - Department of Neurology and Neuroscience, Weill Medical College of Cornell 
      University, New York, NY 10021.
FAU - Pickel, Virginia M
AU  - Pickel VM
LA  - eng
GR  - DA04600/DA/NIDA NIH HHS/United States
GR  - MH 48776/MH/NIMH NIH HHS/United States
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - Synapse
JT  - Synapse (New York, N.Y.)
JID - 8806914
RN  - 0 (2-hydroxy-4,4'-diamidinostilbene, methanesulfonate salt)
RN  - 0 (Fluorescent Dyes)
RN  - 0 (Stilbamidines)
RN  - 58822-25-6 (Enkephalin, Leucine)
SB  - IM
MH  - Animals
MH  - Cerebral Cortex/*cytology/*metabolism
MH  - Cognition/physiology
MH  - Cytoplasm/metabolism
MH  - Dendrites/metabolism
MH  - Enkephalin, Leucine/*metabolism
MH  - Fluorescent Dyes
MH  - Male
MH  - Microscopy, Immunoelectron
MH  - Neural Pathways
MH  - Neurons/metabolism/ultrastructure
MH  - Rats
MH  - Rats, Sprague-Dawley
MH  - Stilbamidines
MH  - Ventral Tegmental Area/*cytology/*metabolism
EDAT- 2004/02/03 05:00
MHDA- 2004/05/08 05:00
CRDT- 2004/02/03 05:00
PHST- 2004/02/03 05:00 [pubmed]
PHST- 2004/05/08 05:00 [medline]
PHST- 2004/02/03 05:00 [entrez]
AID - 10.1002/syn.20000 [doi]
PST - ppublish
SO  - Synapse. 2004 Apr;52(1):38-52. doi: 10.1002/syn.20000.