[Abstract Title]. - Society for Neuroscience

21680 administration decreased baseline activity, but not feeding, and significantly increased
DAMGO-induced feeding. Alternatively, MSX-3 produced robust feeding and activity increases
and facilitated DAMGO-induced behaviors and these were blocked by naltrexone. Overall, it
was observed that A2a receptors exerted stronger modulatory effects than A1 receptors on
consumption and activity, both alone and when co-administered with DAMGO. Indeed, it is
expected that A2a receptors, being more densely localized throughout the accumbens, would
have greater impact on behaviors mediated by the nucleus accumbens than A1 receptors. In
summary, these results suggest an intriguing role for striatal adenosine in mediating baseline and
striatal opioid-mediated behaviors.
Disclosures: C.E. Kelley, None; M.M. Thakkar, None; M.J. Will, 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#: 298.21/TT54
Topic: F.03.d. Reward
Title: D2 receptor manipulations in the sublenticular central extended amygdala affect
responding for brain stimulation reward
Authors: B. FARRAL, *M. A. WARACZYNSKI;
Dept Psychol, Univ. Wisconsin Whitewater, Whitewater, WI
Abstract: Past work in our laboratory has shown that the central extended amygdala (EAc),
especially its sublenticular aspect (SLEAc), is important to the reward effectiveness of medial
forebrain bundle (MFB) stimulation. The medium spiny neurons abundant in this macrostructure
receive dopaminergic input from the A8-A10 cell groups. Given the well-documented role of
dopamine in reward function in the neighboring nucleus accumbens we examined whether
dopamine is important to reward function in the SLEAc. Specifically, we investigated the effects
on MFB self-stimulation of agonizing and antagonizing D1 and D2 dopamine receptors. Male
Long Evans rats received stimulation electrodes in the rostral and caudal MFB and guide
cannulae in the SLEAc both ipsi- and contralateral to the stimulation sites. The stimulation‟s
reward efficacy was assessed using the rate-frequency curve shift technique. Relative to noninjection
baseline conditions, 0.50 µl infusions of 5.0 κg of SKF38393 (D1 agonist) and of 2.0
κg of SCH23390 (D1 antagonist) were as ineffective as saline in altering either the rats‟
maximum rate of responding for stimulation or the frequency required to maintain half-maximal
response rates. The absence of any D1 drug effects may reflect the relative paucity of D1
receptors in the EAc compared to their abundance in neighboring striatopallidum. On the other