PMID- 17683799
OWN - NLM
STAT- MEDLINE
DCOM- 20071113
LR  - 20161124
IS  - 0361-9230 (Print)
IS  - 0361-9230 (Linking)
VI  - 74
IP  - 1-3
DP  - 2007 Sep 14
TI  - GABA/benzodiazepine receptors in the ventromedial hypothalamic nucleus regulate 
      both anxiety and panic-related defensive responses in the elevated T-maze.
PG  - 134-41
AB  - It has been shown that facilitation of GABA-mediated neurotransmission in the 
      medial nucleus of the amygdala and the dorsal periaqueductal gray (dPAG) inhibits 
      the escape, but not the inhibitory avoidance response generated in the elevated 
      T-maze test of anxiety (ETM). These defensive behaviors have been associated with 
      panic and generalized anxiety, respectively. Previous evidence indicates that the 
      dorsomedial part of the ventromedial hypothalamus (VMHdm), which is 
      interconnected with these two brain areas, is also part of the neurobiological 
      substrate controlling escape behavior. In the present study, we investigated in 
      male Wistar rats whether the intra-VMHdm injection of GABA-modulating drugs 
      differently affect the two defensive tasks measured in the ETM. The results 
      showed that the microinjection of the benzodiazepine (BZD) receptor agonist 
      midazolam (10, 20 and 40 nmol), the GABA(A) receptor agonist muscimol (2, 4 and 8 
      nmol) or the GABA(B) receptor agonist baclofen (2, 4 and 8 nmol) impaired 
      inhibitory avoidance and escape performance, an anxiolytic and panicolytic-like 
      effect, respectively. On the other hand, local administration of the BZD inverse 
      agonist FG 7142 (20, 40 and 80 pmol) facilitated both behaviors, suggesting 
      anxiogenic and panicogenic-like effects. These results were not due to motor 
      alterations, since the drugs did not affect exploratory behavior in an open 
      field. The data suggest that GABA(A)/BZD and GABA(B) receptors within the VMHdm 
      are involved not only in the control of panic-related, but also of 
      anxiety-related behaviors.
FAU - Bueno, Cintia Heloina
AU  - Bueno CH
AD  - Laboratorio de Psicofarmacologia, FFCLRP, Universidade de Sao Paulo, 14040-901 
      Ribeirao Preto, SP, Brazil.
FAU - Zangrossi, Helio Jr
AU  - Zangrossi H Jr
FAU - Viana, Milena de Barros
AU  - Viana Mde B
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20070702
PL  - United States
TA  - Brain Res Bull
JT  - Brain research bulletin
JID - 7605818
RN  - 0 (Carbolines)
RN  - 0 (GABA Agonists)
RN  - 0 (GABA Antagonists)
RN  - 0 (GABA Modulators)
RN  - 0 (Receptors, GABA-A)
RN  - 2763-96-4 (Muscimol)
RN  - 60PO70N1BP (FG 7142)
RN  - R60L0SM5BC (Midazolam)
SB  - IM
MH  - Analysis of Variance
MH  - Animals
MH  - Avoidance Learning/drug effects/*physiology
MH  - Behavior, Animal/drug effects
MH  - Carbolines/pharmacology
MH  - Dose-Response Relationship, Drug
MH  - Exploratory Behavior/radiation effects
MH  - GABA Agonists/pharmacology
MH  - GABA Antagonists/pharmacology
MH  - GABA Modulators/pharmacology
MH  - Male
MH  - Maze Learning/drug effects/*physiology
MH  - Midazolam/pharmacology
MH  - Muscimol/pharmacology
MH  - Rats
MH  - Rats, Wistar
MH  - Reaction Time/drug effects
MH  - Receptors, GABA-A/*physiology
MH  - Ventromedial Hypothalamic Nucleus/drug effects/*metabolism
EDAT- 2007/08/09 09:00
MHDA- 2007/11/14 09:00
CRDT- 2007/08/09 09:00
PHST- 2007/02/23 00:00 [received]
PHST- 2007/06/01 00:00 [revised]
PHST- 2007/06/07 00:00 [accepted]
PHST- 2007/08/09 09:00 [pubmed]
PHST- 2007/11/14 09:00 [medline]
PHST- 2007/08/09 09:00 [entrez]
AID - S0361-9230(07)00187-6 [pii]
AID - 10.1016/j.brainresbull.2007.06.003 [doi]
PST - ppublish
SO  - Brain Res Bull. 2007 Sep 14;74(1-3):134-41. doi: 
      10.1016/j.brainresbull.2007.06.003. Epub 2007 Jul 2.