D-cycloserine retards recovery from consummatory successive negative contrast

NORRIS, J. N.; ORTEGA, L. A.; LOPEZ SEAL, M. F.; PAPINI, M. R

Chicago

Otro; Neuroscience 2009; 2009

Society for Neuroscience

<!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:EN-US; mso-fareast-language:EN-US;} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> Five experiments explored the role of the N-methyl D-aspartate (NMDA) receptor in consummatory successive negative contrast (cSNC). In cSNC, an incentive downshift from 32% sucrose to 4% sucrose induces a transient suppression of consummatory behavior. These experiments were designed to determine whether animals consolidate a memory of the downshift experience (called egocentric memory). The partial agonist D-cycloserine (DCS; 30 mg/kg) administered before (Experiment 1) or immediately after (Experiment 2) the first downshift trial enhanced cSNC. The effect of posttrial DCS was attenuated when a milder incentive discrepancy from 32% to 6% sucrose was used (Experiment 2). In Experiment 3, DCS at 15 mg/kg and 60 mg/kg prolonged cSNC mildly (32%-to-4% sucrose downshift). There was no evidence that the enhancement of cSNC induced by DCS was the result of conditioned taste aversion (Experiment 4). Finally, the partial agonist HA966 (6 mg/kg) administered immediately after the first downshift trial also enhanced cSNC (Experiment 5). These results provide the first evidence that activation of NMDA receptors via the glycine-modulatory site enhances the egocentric emotional memory of the incentive downshift experience.