[Abstract Title]. - Society for Neuroscience

to the VP. Here we began to functionally map the critical aversive sites for production of
„disliking‟ induced by excitotoxin lesion, or by microinjection of inactivating agents: lidocaine
or GABA agonists. In order to do so, we measured rats‟ aversive “disliking‟ response induced by
sucrose and quinine after microinjection of muscimol/baclofen cocktail, lidocaine, or one of the
two excitotoxins (quinolinic acid or ibotenic acid). We then functionally mapped the behavioral
effects onto the corresponding localization of microinjection. We aimed to identify the most
critical site at which the drug caused significant aversion enhancement. Our preliminary data
show that VP and nearby regions are crucial to reward processing, and local inactivation there
causes production of aversive „disliking‟. This finding may extend our understanding of the role
of VP in reward processing and carry implications for understanding hedonic dysfunction in drug
addiction, obesity and mood disorders.
Disclosures: C. Ho , None; K.C. Berridge, None.
Poster
298. Neural Mechanisms of Reward: Self-Administration and Opioid Modulation
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 298.16/TT49
Topic: F.03.d. Reward
Support: NIH Grants MH63649
NIH Grant DA15188
Title: Feeding and sensorimotor suppression by metabotropic glutamate receptor blockade in
medial shell of nucleus accumbens
Authors: *J. M. RICHARD, K. C. BERRIDGE;
Psychology, Univ. Michigan, Ann Arbor, MI
Abstract: Metabotropic glutamate receptors are the target of many new drugs aimed at clinical
problems relevant to both affect and motivational processes, including drug addiction and
withdrawal, anxiety, and schizophrenia. Here we tested whether blockade of Group II
metabotropic glutamate receptors in medial shell of nucleus accumbens alters affective and/or
motivated behaviors. Microinjection of mglu2/3 antagonist LY341495 (10 κg per .5 κl) reduced
eating behavior and food intake without reducing overall locomotion in the form of cage crosses
and rears. Additionally, we tested the effect of LY341495 microinjections using the taste
reactivity test. We found that mglu2/3 blockade mildly reduced both positive and negative