Medicine and Health Sciences Commons^™

Altered Gating Of KV1.4 In The Nucleus Accumbens Suppresses Motivation For Reward, Bernadette O'Donovan, Adewale Adeluyi, Erin L Anderson, Robert D. Cole, Jill R. Turner, Pavel I. Ortinski

Neuroscience Faculty Publications

Deficient motivation contributes to numerous psychiatric disorders, including withdrawal from drug use, depression, schizophrenia, and others. Nucleus accumbens (NAc) has been implicated in motivated behavior, but it remains unclear whether motivational drive is linked to discrete neurobiological mechanisms within the NAc. To examine this, we profiled cohorts of Sprague-Dawley rats in a test of motivation to consume sucrose. We found that substantial variability in willingness to exert effort for reward was not associated with operant responding under low-effort conditions or stress levels. Instead, effort-based motivation was mirrored by a divergent NAc shell transcriptome with differential regulation at potassium and dopamine …

The Effects Of Nicotine In The Neonatal Quinpirole Rodent Model Of Psychosis: Neural Plasticity Mechanisms And Nicotinic Receptor Changes, Daniel J. Peterson, W. Drew Gill, John M. Dose, Donald B. Hoover, James R. Pauly, Elizabeth D. Cummins, Katherine C. Burgess, Russell W. Brown

Pharmaceutical Sciences Faculty Publications

Neonatal quinpirole (NQ) treatment to rats increases dopamine D2 receptor sensitivity persistent throughout the animal’s lifetime. In Experiment 1, we analyzed the role of α7 and α4β2 nicotinic receptors (nAChRs) in nicotine behavioral sensitization and on the brain-derived neurotrophic factor (BDNF) response to nicotine in NQ- and neonatally saline (NS)-treated rats. In Experiment 2, we analyzed changes in α7 and α4β2 nAChR density in the nucleus accumbens (NAcc) and dorsal striatum in NQ and NS animals sensitized to nicotine. Male and female Sprague-Dawley rats were neonatally treated with quinpirole (1 mg/kg) or saline from postnatal days (P)1–21. Animals were given …

The Effect Of Sazetidine-A And Other Nicotinic Ligands On Nicotine Controlled Goal-Tracking In Female And Male Rats, S. Charntikov, A. M. Falco, K. Fink, Linda P. Dwoskin, R. A. Bevins

Pharmaceutical Sciences Faculty Publications

Nicotine is the primary addictive component of tobacco products and its complex stimulus effects are readily discriminated by humans and non-human animals. Previous preclinical research investigating directly the nature of the nicotine stimulus has been limited to male rodents. The current study began to address this significant gap in the literature by training female and male rats to discriminate 0.4 mg/kg nicotine from saline in the discriminated goal-tracking task. In this task, access to sucrose was intermittently available on nicotine session. On saline session, intermixed with nicotine sessions on separate days, sucrose was not available. Both sexes acquired the discrimination …

AΒ40 Reduces P-Glycoprotein At The Blood-Brain Barrier Through The Ubiquitin-Proteasome Pathway, Anika M. S. Hartz, Yu Zhong, Andrea Wolf, Harry Levine Iii, David S. Miller, Björn Bauer

Sanders-Brown Center on Aging Faculty Publications

Failure to clear amyloid-β (Aβ) from the brain is in part responsible for Aβ brain accumulation in Alzheimer's disease (AD). A critical protein for clearing Aβ across the blood–brain barrier is the efflux transporter P-glycoprotein (P-gp) in the luminal plasma membrane of the brain capillary endothelium. P-gp is reduced at the blood–brain barrier in AD, which has been shown to be associated with Aβ brain accumulation. However, the mechanism responsible for P-gp reduction in AD is not well understood. Here we focused on identifying critical mechanistic steps involved in reducing P-gp in AD. We …

Blockade Of Astrocytic Calcineurin/Nfat Signaling Helps To Normalize Hippocampal Synaptic Function And Plasticity In A Rat Model Of Traumatic Brain Injury, Jennifer L. Furman, Pradoldej Sompol, Susan D. Kraner, Melanie M. Pleiss, Esther J. Putman, Jacob Dunkerson, Hafiz Mohmmad Abdul, Kelly N. Roberts, Stephen William Scheff, Christopher M. Norris

Pharmacology and Nutritional Sciences Faculty Publications

Increasing evidence suggests that the calcineurin (CN)-dependent transcription factor NFAT (Nuclear Factor of Activated T cells) mediates deleterious effects of astrocytes in progressive neurodegenerative conditions. However, the impact of astrocytic CN/NFAT signaling on neural function/recovery after acute injury has not been investigated extensively. Using a controlled cortical impact (CCI) procedure in rats, we show that traumatic brain injury is associated with an increase in the activities of NFATs 1 and 4 in the hippocampus at 7 d after injury. NFAT4, but not NFAT1, exhibited extensive labeling in astrocytes and was found throughout the axon/dendrite layers of CA1 and the dentate …

Rod Microglia: Elongation, Alignment, And Coupling To Form Trains Across The Somatosensory Cortex After Experimental Diffuse Brain Injury, Jenna M. Ziebell, Samuel E. Taylor, Tuoxin Cao, Jordan L. Harrison, Jonathan Lifshitz

Neuroscience Faculty Publications

BACKGROUND: Since their discovery, the morphology of microglia has been interpreted to mirror their function, with ramified microglia constantly surveying the micro-environment and rapidly activating when changes occur. In 1899, Franz Nissl discovered what we now recognize as a distinct microglial activation state, microglial rod cells (Stäbchenzellen), which he observed adjacent to neurons. These rod-shaped microglia are typically found in human autopsy cases of paralysis of the insane, a disease of the pre-penicillin era, and best known today from HIV-1-infected brains. Microglial rod cells have been implicated in cortical 'synaptic stripping' but their exact role has remained unclear. This is …

Striatal Neuroinflammation Promotes Parkinsonism In Rats, Dong-Young Choi, Mei Liu, Randy L. Hunter, Wayne A. Cass, Jignesh D. Pandya, Patrick G. Sullivan, Eun-Joo Shin, Hyoung-Chun Kim, Don M. Gash, Guoying Bing

Neuroscience Faculty Publications

BACKGROUND: Sporadic Parkinson's disease (PD) is a progressive neurodegenerative disorder with unknown cause, but it has been suggested that neuroinflammation may play a role in pathogenesis of the disease. Neuroinflammatory component in process of PD neurodegeneration was proposed by postmortem, epidemiological and animal model studies. However, it remains unclear how neuroinflammatory factors contribute to dopaminergic neuronal death in PD.

FINDINGS: In this study, we analyzed the relationship among inducible nitric oxide synthase (iNOS)-derived NO, mitochondrial dysfunction and dopaminergic neurodegeneration to examine the possibility that microglial neuroinflammation may induce dopaminergic neuronal loss in the substantia nigra. Unilateral injection of lipopolysaccharide (LPS) …

Pioglitazone Inhibition Of Lipopolysaccharide-Induced Nitric Oxide Synthase Is Associated With Altered Activity Of P38 Map Kinase And Pi3k/Akt, Bin Xing, Tao Xin, Randy Lee Hunter, Guoying Bing

Neuroscience Faculty Publications

BACKGROUND: Previous studies have suggested that peroxisome proliferator activated receptor-gamma (PPAR-gamma)-mediated neuroprotection involves inhibition of microglial activation and decreased expression and activity of inducible nitric oxide synthase (iNOS); however, the underlying molecular mechanisms have not yet been well established. In the present study we explored: (1) the effect of the PPAR-gamma agonist pioglitazone on lipopolysaccharide (LPS)-induced iNOS activity and nitric oxide (NO) generation by microglia; (2) the differential role of p38 mitogen-activated protein kinase (p38 MAPK), c-Jun NH(2)-terminal kinase (JNK), and phosphoinositide 3-kinase (PI3K) on LPS-induced NO generation; and (3) the regulation of p38 MAPK, JNK, and PI3K by pioglitazone. …

Prenatal Cocaine Exposure Alters Alpha2 Receptor Expression In Adolescent Rats, Rosemarie M. Booze, David R. Wallace, Janelle M. Silvers, Barbara J. Strupp, Diane M. Snow, Charles F. Mactutus

Neuroscience Faculty Publications

BACKGROUND: Prenatal cocaine exposure produces attentional deficits which to persist through early childhood. Given the role of norepinephrine (NE) in attentional processes, we examined the forebrain NE systems from prenatal cocaine exposed rats. Cocaine was administered during pregnancy via the clinically relevant intravenous route of administration. Specifically, we measured alpha2-adrenergic receptor (alpha2-AR) density in adolescent (35-days-old) rats, using [3H]RX821002 (5 nM).

RESULTS: Sex-specific alterations of alpha2-AR were found in the hippocampus and amygdala of the cocaine-exposed animals, as well as an upregulation of alpha2-AR in parietal cortex.

CONCLUSION: These data suggest that prenatal cocaine exposure results in a persistent alteration …