[Abstract Title]. - Society for Neuroscience

compartment may play a different role in the reward and motivational factors underlying
behavioral acts such as cocaine self-administration. The present study attempts to better
understand the contributions of the DMS and the INT to producing drug-seeking behavioral
responses. Rats are trained to intravenously self-administer cocaine, extinguished, and subjected
to a reinstatement treatment consiting of an intracranial amphetamine (AMPH) microinfusion in
either the DMS or the INT. This microinfusion is performed using a hands-free intracranial
micropump system capable of reproducibly delivering nanoliter volumes while the subject is in
the operant chamber. Initial results from low and high volume (300 nL and 900 nL of 0.1
nmoles/nL AMPH, respectively) AMPH microinfusions show reinstatement behavior that
respects the NAc shell anatomy compartmentalization.
Disclosures: D.G.C. Hildebrand, None; A. Tang, None; K.M. Morin, None; M. Chan,
None; J.R. Stellar, 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#: 298.8/TT41
Topic: F.03.d. Reward
Support: Robertson Fund of Emory University
Title: Intraventricular serotonin does not affect the reward of ventral tegmental self-stimulation
Authors: *D. B. NEILL 1 , A. COKER 2 ;
1 Dept Psychology, 2 Neurosci. and Behavioral Biol. Program, Emory Univ., Atlanta, GA
Abstract: Serotonin-selective reuptake inhibitors (SSRIs) are widely used in the treatment of
depression. One of the hallmarks of major depression is anhedonia, a loss of the appreciation of
pleasure. Pleasure in humans is often equated with reward in non-human animals. Paradoxically,
both acute and chronic treatment with SSRIs appear to reduce reward, and thus perhaps pleasure,
in tests with non-human animals. One of these tests is intracranial self-stimulation (ICSS), in
which an animal performs a response to deliver electrical stimulation to a brain site via an
implanted electrode. We examined the effect of a global increase in serotonin, via
intraventricular administration, on autotitration ICSS in male Sprague-Dawley rats. Doses of 10
and 20 µg serotonin HCl, dissolved in 10 µl artificial cerebrospinal fluid, were injected into the
lateral ventricle contralateral to a bipolar ICSS electrode implanted in the ventral tegmental area.
In our autotitration procedure, the intensity of brain stimulation declined 3 µa every 5th response
on a “stimulation” lever; a single response on a second “reset” lever reset the intensity at the