Fh. Mendonca et al., INTRAVENTRICULAR CYCLOHEXIMIDE ATTENUATES THE RESTRAINT-INDUCED LONG-LASTING EFFECT ON PLUS-MAZE EXPLORATION, Brazilian journal of medical and biological research, 29(4), 1996, pp. 501-505
Rats submitted to 2 h of restraint stress show reduced open arm explor
ation in the elevated plus maze 24 h later. To determine if this effec
t is dependent on protein synthesis during or after the restraint peri
od, cycloheximide, a protein synthesis inhibitor, was injected into th
e right cerebral ventricle of male Wistar rats (200-250 g), immediatel
y before (N = 19 animals per group), immediately after (N = 7 animals
per group) or 2 h (N = 10 animals per group) following a 2-h period of
forced restraint. Twenty-four hours later the animals were tested in
the elevated plus maze. Non-stressed control groups received saline (S
AL, N = 8-9 per group) or cycloheximide (CHX, N = 8-9 per group) and w
ere tested 1 h or 24 h later in the maze. Pre- but not post-stress mic
roinjections of cycloheximide (20 mu g in 2 mu l) increased exploratio
n in the elevated plus maze (% of time spent in open arms, pre-stress
injection: SAL = 4.6 +/- 1.2, CHX = 10.7 +/- 2.3; number of enclosed a
rms entries: SAL = 3.6 +/- 0.5, CHX = 5.6 +/- 0.4). No drug effect was
observed in non-stressed animals. These results suggest that blockade
of protein synthesis during the restraint period may attenuate the be
havioral consequences of stress.