TITLE:
Buspirone Ameliorates the Morphine Withdrawal-Induced Anxiety through Synaptic Ultrastructural Changes in Hippocampus of Rat
AUTHORS:
Jialin Gao, Gang Qian, Suyuan Luo, Yan Tian, Mingsong Wu, Zhongxiang Yao
KEYWORDS:
Buspirone; Morphine; Anxiety; Synaptic Ultrastructure; Hippocampus
JOURNAL NAME:
Psychology,
Vol.4 No.10A,
October
17,
2013
ABSTRACT: Morphine administration causes long-lasting neural changes in the
brain that underpin the behavioral abnormalities, and the relationship between structural changes and behavioral symptoms is obscure. In present study, the
elevated plus-maze and transmission electron microscope were applied to validate the anxiety-like
behaviors and synaptic ultrastructural changes in the hippocampi of rats among the morphine
group (morphine administration only), the buspirone group (morphine plus
buspirone administration) and the vehicle (saline treated only). As compared
with the vehicle group, lower values of OE (times of entering into the open
arms), OE% (percentage of entries into the open arms), OT (time spent in the
open arms), OT% (percentage of time stayed in the open arms), Ns (surface density
(Sv)/numerical density (Nv)) and S (surface
area) of synapses were observed in the
morphine group , but significantly, behavior higher scores of RR (rearing), HD
(head-dipping), FBA (flat back approach), and higher Nv, Sv, PSD (postsynaptic
density), LPT (length of postsynaptic thickening), WCJ (widths in synaptic
cleft on junctions) and CCR (curvature of the cleft region) of synapses
appeared in the morphine group. However, no significant differences in values
of most of those parameters above were detected between the vehicle group and
the buspirone group. These results supported that anxiety-like symptoms
of rats significantly occurred to the
rats after acute morphine withdrawal, but buspirone administration could
reverse these indexes. It also proved that the appearance/disappearance of
anxiety-related symptoms was related to the ultrastructural
changes/reversibility of synapses in the hippocampus with morphine and
buspirone administrations. So, it suggested that anxiety-related symptoms were
modified in rats subjected to the synaptic ultrastructural changes in
hippocampus by morphine acute withdrawal and were further rehabilitated
by buspirone administration. It is helpful to pursue the effective therapeutic
methods of morphine addiction.