2 research outputs found
Role of 5-HT 1A receptors in antidepressant-like effect of dichloromethane fraction of Kielmeyera coriacea in rats subjected to the forced swim test
Objective : We examined the involvement of 5-HT neurotransmission on
the antidepressant-like effect of the dichloromethane (DcM) fraction of
an extract from Kielmeyera coriacea stems. Materials and Methods :
Male Wistar rats treated chronically (45 days, gavage) with the DcM
fraction received an intradorsal raphe nucleus (DRN) microinjection of
saline or 5-HT 1A receptor ligands and were evaluated in the forced
swimming test (FST) and in the open-field test (OFT). Results : The
DcM fraction (5.0 mg/kg) reduced immobility time in the FST without
altering locomotion in the OFT. IntraDRN microinjection of the 5-HT 1A
receptor agonist, (+)-8-OH-DPAT (0.10; 0.20 or 0.33 μg) increased
immobility time and reduced locomotion at the higher dose whereas the
5-HT1A antagonists, (-)-pindolol (0.10; 0.20 or 0.40 μg) or
WAY100635 (0.11; 0.22 or 0.43 μg) did not produce any effect in
the behavioral tests. IntraDRN (+)-8-OH-DPAT (0.20 or 0.33 μg) in
rats treated with the DcM fraction (5.0 mg/kg) blocked the changes in
the immobility time or in locomotion produced by each drug. Intra-DRN
(-)-pindolol (0.10 μg) or WAY100635 (0.43 μg) in rats treated
with a subactive dose of the DcM fraction (4.0 mg/kg) synergistically
reduced immobility time in the FST. Conclusion : The DcM fraction of
Kielmeyera coriacea produced an antidepressant-like effect in the FST
and interacted with 5-HT 1A receptor ligands. Activation of 5-HT 1A
receptors into DRN by (+) 8-OH-DPAT produced detectable changes in the
FST or in the OFT