PMID- 11173220
OWN - NLM
STAT- MEDLINE
DCOM- 20010510
LR  - 20191104
IS  - 0891-0618 (Print)
IS  - 0891-0618 (Linking)
VI  - 21
IP  - 1
DP  - 2001 Jan
TI  - Ultrastructural evidence for enkephalin mediated disinhibition in the 
      ventromedial nucleus of the hypothalamus.
PG  - 53-62
AB  - The ventromedial nucleus of the hypothalamus (VMN) regulates the 
      estrogen-dependent appearance of female mating behavior, lordosis. Accumulating 
      evidence suggests that estrogen might exert its control over lordosis by acting, 
      in part, on neurons that contain enkephalin in the VMN. The expression of the 
      enkephalin precursor gene is robustly stimulated by estrogen and is correlated 
      with the later appearance of lordosis. GABA has also been implicated as an 
      important neurotransmitter for the appearance of lordosis. Because enkephalin is 
      thought to act in several brain areas to modulate the activity of GABAergic 
      neurons, we studied the ultrastructural morphology and relationship between 
      neurons containing these neurochemicals using dual-labeling immunocytochemistry 
      in ovariectornized rats, half of which received estrogen replacement. 
      Immunolabeling for enkephalin was almost always detected within axon terminals 
      (695 axonal profiles sampled), while GABA immunoreactivity was more often 
      localized to cell bodies and dendrites (191 profiles), than to axons (63 
      profiles). Axon terminals containing enkephalin immunolabeling provided a major 
      innervation to soma or dendrites containing GABA. That is, over one third 
      (94/245) of the axon terminals in contact with GABA-immunoreactive dendrites 
      contained enkephalin. Furthermore, these GABA-immunoreactive dendrites accounted 
      for a fifth of the somatodendritic processes associated with 
      enkephalin-containing axon terminals. These findings support the hypothesis that 
      enkephalin may act in the VMN by inhibiting GABAergic neurons, which could result 
      in the disinhibition of neural circuits relevant for lordosis.
FAU - Commons, K G
AU  - Commons KG
AD  - Laboratory of Neurobiology and Behavior, The Rockefeller University, 1230 York 
      Avenue, Box 275, New York, NY 10012, USA. commonk@yahoo.com
FAU - Pfaff, D W
AU  - Pfaff DW
LA  - eng
PT  - Journal Article
PL  - Netherlands
TA  - J Chem Neuroanat
JT  - Journal of chemical neuroanatomy
JID - 8902615
RN  - 0 (Enkephalins)
RN  - 0 (Estrogens)
RN  - 56-12-2 (gamma-Aminobutyric Acid)
SB  - IM
MH  - Animals
MH  - Enkephalins/*physiology
MH  - Estrogens/physiology
MH  - Female
MH  - Immunohistochemistry
MH  - Presynaptic Terminals/physiology/ultrastructure
MH  - Rats
MH  - Rats, Sprague-Dawley
MH  - Ventromedial Hypothalamic Nucleus/*physiology/*ultrastructure
MH  - gamma-Aminobutyric Acid/metabolism
EDAT- 2001/02/15 11:00
MHDA- 2001/05/22 10:01
CRDT- 2001/02/15 11:00
PHST- 2001/02/15 11:00 [pubmed]
PHST- 2001/05/22 10:01 [medline]
PHST- 2001/02/15 11:00 [entrez]
AID - S0891-0618(00)00093-4 [pii]
AID - 10.1016/s0891-0618(00)00093-4 [doi]
PST - ppublish
SO  - J Chem Neuroanat. 2001 Jan;21(1):53-62. doi: 10.1016/s0891-0618(00)00093-4.