Interactive effects of a protein kinase AII inhibitor and testosterone on spatial learning in the Morris water maze.
Neurohormones such as testosterone (TE) are important in modulation of learning and memory. In the present study, we investigated the interactive effects of pre-training bilateral intra-hippocampal infusions of testosterone and H-89, a selective PKAII inhibitor, on spatial acquisition in the Morris water maze (MWM). Different doses of TE (20, 40 and 80 μg/side) and H-89 (5 and 10 μM/side) were administered 30 min before start of the training each day. Control animals received bilateral intra-hippocampal infusions of DMSO as vehicle for TE and H-89. Animals were trained for 4 days and each day included one block of four trials. The results of this study showed that bilateral infusion of TE (40 and 80 μg/side) or H-89 (10 μM/side) impaired spatial learning as indicated by significant increases in escape latency and traveled distance compared to the control group. Although pre-training bilateral infusions of a low concentration of either TE (20 μg/side) or H-89 (5 μM/side) into the CA1 region of the hippocampus did not affect learning capabilities, but the combination of the low doses of the drugs led to significant deficits in spatial acquisition. Overall, our data suggest that spatial acquisition was affected by PKAII inhibition or TE administration. Moreover, when co-administered, these drugs had a negative synergistic impact on acquisition.
Department of Pharmacology and Toxicology, Pharmaceutical Sciences Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran.
Tina
T
Khorshidahmad
Kaveh
K
Tabrizian
Gelareh
G
Vakilzadeh
Parmida
P
Nikbin
Shahla
S
Moradi
Ali
A
Hosseini-Sharifabad
Ali
A
Roghani
Nasser
N
Naghdi
Mohammad
M
Sharifzadeh
D000704:Analysis of Variance; D000728:Androgens / Q000494:pharmacology*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004924:Escape Reaction / Q000187:drug effects; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology; D007546:Isoquinolines / Q000494:pharmacology*; D008124:Locomotion / Q000187:drug effects; D008297:Male; D018782:Maze Learning / Q000187:drug effects*; D008845:Microinjections; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D011930:Reaction Time / Q000187:drug effects; D013028:Space Perception / Q000187:drug effects*; D013449:Sulfonamides / Q000494:pharmacology*; D013550:Swimming / Q000523:psychology; D013739:Testosterone / Q000494:pharmacology*; D013997:Time Factors
D000728:Androgens; D007546:Isoquinolines; D047428:Protein Kinase Inhibitors; D013449:Sulfonamides; D013739:Testosterone; C063509:N-(2-(4-bromocinnamylamino)ethyl)-5-isoquinolinesulfonamide