Neurosciences Commons^™

The Incentive Amplifying Effects Of Nicotine Are Reduced By Selective And Non-Selective Dopamine Antagonists In Rats, Matthew I. Palmatier, Marissa R. Kellicut, A. Brianna Sheppard, Russell W. Brown, Donita L. Robinson

Russell W. Brown

Nicotine is a psychomotor stimulant with ‘reinforcement enhancing’ effects — the actions of nicotine in the brain increase responding for non-nicotine rewards. We hypothesized that this latter effect of nicotine depends on increased incentive properties of anticipatory cues; consistent with this hypothesis, multiple laboratories have reported that nicotine increases sign tracking, i.e. approach to a conditioned stimulus (CS), in Pavlovian conditioned-approach tasks. Incentive motivation and sign tracking are mediated by mesolimbic dopamine (DA) transmission and nicotine facilitates mesolimbic DA release. Therefore, we hypothesized that the incentive-promoting effects of nicotine would be impaired by DA antagonists. To test this hypothesis, separate …

Neuronal Reorganization In Adult Rats Neonatally Exposed To (±)-3,4-Methylenedioxymethamphetamine, Michael T. Williams, Matthew R. Skelton, Ian D. Longacre, Kimberly N. Huggins, Amanda M. Maple, Charles V. Vorhees, Russell W. Brown

Russell W. Brown

The abuse of methylenedioxymethamphetamine (MDMA) during pregnancy is of concern. MDMA treatment of rats during a period of brain growth analogous to late human gestation leads to neurochemical and behavioral changes. MDMA from postnatal day (P)11–20 in rats produces reductions in serotonin and deficits in spatial and route-based navigation. In this experiment we examined the impact of MDMA from P11 to P20 (20 mg/kg twice daily, 8 h apart) on neuronal architecture. Golgi impregnated sections showed significant changes. In the nucleus accumbens, the dendrites were shorter with fewer spines, whereas in the dentate gyrus the dendritic length was decreased but …

Intravenous Prenatal Nicotine Exposure Alters Meth-Induced Hyperactivity, Conditioned Hyperactivity, And Bdnf In Adult Rat Offspring, Ryan T. Lacy, Russell. W. Brown, Amanda J. Morgan, Charles F. Mactutus, Steven B. Harrod

Russell W. Brown

In the USA, approximately 15% of women smoke tobacco cigarettes during pregnancy. In utero tobacco smoke exposure produces somatic growth deficits like intrauterine growth restriction and low birth we

Corticosterone Administration Up-Regulated Expression Of Norepinephrine Transporter And Dopamine Β-Hydroxylase In Rat Locus Coeruleus And Its Terminal Regions, Yan Fan, Ping Ping Chen, Ying Li, Kui Cui, Daniel M. Noel, Elizabeth D. Cummins, Daniel J. Peterson, Russell W. Brown, Meng-Yang Zhu

Russell W. Brown

Stress has been reported to activate the locus coeruleus (LC)-noradrenergic system. In this study, corticosterone (CORT) was orally administrated to rats for 21 days to mimic stress status. In situ hybridization measurements showed that CORT ingestion significantly increased mRNA levels of norepinephrine transporter (NET) and dopamine β-hydroxylase (DBH) in the LC region. Immunofluorescence staining and western blotting revealed that CORT treatment also increased protein levels of NET and DBH in the LC, as well as NET protein levels in the hippocampus, the frontal cortex and the amygdala. However, CORT-induced increase in DBH protein levels only appeared in the hippocampus and …

Elevated Dna Oxidation And Dna Repair Enzyme Expression In Brain White Matter In Major Depressive Disorder, Attila Szebeni, Katalin Szebeni, Timothy P. Diperi, Luke A. Johnson, Craig A. Stockmeier, Jessica D. Crawford, Michelle J. Chandley Health Sciences, Liza J. Hernandez, Katherine C. Burgess, Russell W. Brown, Gregory A. Ordway

Russell W. Brown

Background: Pathology of white matter in brains of patients with major depressive disorder (MDD) is well-documented, but the cellular and molecular basis of this pathology are poorly understood.

Methods:Levels of DNA oxidation and gene expression of DNA damage repair enzymes were measured in Brodmann area 10 (BA10) and/or amygdala (uncinate fasciculus) white matter tissue from brains of MDD (n=10) and psychiatrically normal control donors (n=13). DNA oxidation was also measured in BA10 white matter of schizophrenia donors (n=10) and in prefrontal cortical white matter from control rats (n=8) and rats with repeated stress-induced anhedonia (n=8).

Results:DNA oxidation …