Medicine and Health Sciences Commons^™

Seasonal Plasticity In GabaA Signaling Is Necessary For Restoring Phase Synchrony In The Master Circadian Clock Network, Kayla Rohr, Harshida Pancholi, Shabi Haider, Christopher Karow, David Modert, Nicholas J. Raddatz, Jennifer A. Evans

Biomedical Sciences Faculty Research and Publications

Annual changes in the environment threaten survival, and numerous biological processes in mammals adjust to this challenge via seasonal encoding by the suprachiasmatic nucleus (SCN). To tune behavior according to day length, SCN neurons display unified rhythms with synchronous phasing when days are short, but will divide into two sub-clusters when days are long. The transition between SCN states is critical for maintaining behavioral responses to seasonal change, but the mechanisms regulating this form of neuroplasticity remain unclear. Here we identify that a switch in chloride transport and GABA_A signaling is critical for maintaining state plasticity in the SCN …

Circuit-Specific Control Of The Medial Entorhinal Inputs To The Dentate Gyrus By Atypical Presynaptic Nmdars Activated By Astrocytes, Iaroslav Savtchouk, Maria Amalia Di Castro, Rugina Ali, Hiltrud Stubbe, Rafael Lujan, Andrea Volterra

Biomedical Sciences Faculty Research and Publications

Here, we investigated the properties of presynaptic N-methyl-D-aspartate receptors (pre-NMDARs) at corticohippocampal excitatory connections between perforant path (PP) afferents and dentate granule cells (GCs), a circuit involved in memory encoding and centrally affected in Alzheimer’s disease and temporal lobe epilepsy. These receptors were previously reported to increase PP release probability in response to gliotransmitters released from astrocytes. Their activation occurred even under conditions of elevated Mg²⁺ and lack of action potential firing in the axons, although how this could be accomplished was unclear. We now report that these pre-NMDARs contain the GluN3a subunit conferring them low Mg^{2+ …}

Enhancing Cell Seeding And Osteogenesis Of Mscs On 3d Printed Scaffolds Through Injectable Bmp2 Immobilized Ecm-Mimetic Gel, Farahnaz Fahimipour, Erfan Dashtimoghadam, Mohammad Mahdi Hasani-Sadrabadi, Jessica Vargas, Daryoosh Vashaee, Doug Lobner, Tahereh S. Jafarzadeh Kashi, Behnam Ghasemzadeh, Lobat Tayebi

Biomedical Sciences Faculty Research and Publications

Objective

Design of bioactive scaffolds with osteogenic capacity is a central challenge in cell-based patient-specific bone tissue engineering. Efficient and spatially uniform seeding of (stem) cells onto such constructs is vital to attain functional tissues. Herein we developed heparin functionalized collagen gels supported by 3D printed bioceramic scaffolds, as bone extracellular matrix (ECM)-mimetic matrices. These matrices were designed to enhance cell seeding efficiency of mesenchymal stem cells (MSCs) as well as improve their osteogenic differentiation through immobilized bone morphogenic protein 2 (BMP2) to be used for personalized bone regeneration.

Methods

A 3D gel based on heparin-conjugated collagen matrix capable of …

Positions In The N‐Methyl‐D‐Aspartate Receptor Glun2c Subunit M3 And M4 Domains Regulate Alcohol Sensitivity And Receptor Kinetics, Man Wu, Priya Katti, Yulin Zhao, Robert W. Peoples

Biomedical Sciences Faculty Research and Publications

Background

Alcohol alters synaptic transmission in the brain. The N‐methyl‐D‐aspartate (NMDA) receptor (NMDAR), a subtype of glutamate‐gated ion channel, is an important synaptic target of alcohol in the brain. We and others have previously identified 4 alcohol‐sensitive positions in the third and fourth membrane‐associated (M) domains, designated M3_1‐2and M4_1‐2, of the GluN1, GluN2A, and GluN2B NMDAR subunits. In the present study, we tested whether the corresponding positions in the GluN2C subunit also regulate alcohol sensitivity and ion channel gating.

Methods

We performed alanine‐ and tryptophan‐scanning mutagenesis in the GluN2C subunit followed by expression in HEK …

Roles For The Uptake2 Transporter Oct3 In Regulation Of Dopaminergic Neurotransmission And Behavior, Paul J. Gasser

Biomedical Sciences Faculty Research and Publications

Transporter-mediated uptake determines the peak concentration, duration, and physical spread of released monoamines. Most studies of monoamine clearance focus on the presynaptic uptake₁ transporters SERT, NET and DAT. However, recent studies have demonstrated the expression of the uptake₂ transporter OCT3 (organic cation transporter 3), throughout the rodent brain. In contrast to NET, DAT and SERT, OCT3 has higher capacity and lower affinity for substrates, is sodium-independent, and is multi-specific, with the capacity to transport norepinephrine, dopamine, serotonin and histamine. OCT3is insensitive to inhibition by cocaine and antidepressant drugs but is inhibited directly by the glucocorticoid hormone corticosterone. Thus, …

Determinants Of Occupational Injuries Among Building Construction Workers In Kampala City, Uganda, Arthur Kiconco, Nathan Ruhinda, Abdullah Ali Halage, Stephen Watya, William Bazeyo, John C. Ssempebwa, Joseph Byonanebye

Biomedical Sciences Faculty Research and Publications

Background

Globally, about 1000 people die and close to 860,000 people sustain injury at work daily. Injury prevention and control require contextual evidence, although most studies in Uganda have focused on general causes. Factors associated with occupational injuries among building construction workers were assessed in this study.

Methods

A cross-sectional study among building construction workers was conducted in Kampala, Uganda. A standardized semi-structured questionnaire was used to collect data. Three hundred nineteen (319) participants were randomly and proportionately selected from 57 construction sites. Descriptive statistics were used to describe the variables while generalized linear modeling was used to estimate the …

Mice, Acorns, And Lyme Disease: A Case Study To Teach The Ecology Of Emerging Infectious Diseases, Laurieann Klockow

Biomedical Sciences Faculty Research and Publications

Ebola, Zika, the recall of contaminated lettuce - these are just a few recent outbreaks making headlines. Students should be able to connect what they learn in their biology courses to explain these events happening around them. Unfortunately, students do not necessarily make those connections. Therefore, it is important, as instructors, to provide opportunities where students engage with societal issues and problems related to course content and case studies, using headlines from the news are one way to do this.

Here I describe a case study about Lyme disease that engages students in learning about the ecology of infectious disease. …

Prefrontal-Accumbens Opioid Plasticity: Implications For Relapse And Dependence, Matthew C. Hearing

Biomedical Sciences Faculty Research and Publications

In addiction, an individual’s ability to inhibit drug seeking and drug taking is thought to reflect a pathological strengthening of drug-seeking behaviors or impairments in the capacity to control maladaptive behavior. These processes are not mutually exclusive and reflect drug-induced modifications within prefrontal cortical and nucleus accumbens circuits, however unlike psychostimulants such as cocaine, far less is known about the temporal, anatomical, and cellular dynamics of these changes. We discuss what is known regarding opioid-induced adaptations in intrinsic membrane physiology and pre-/postsynaptic neurotransmission in principle pyramidal and medium spiny neurons in the medial prefrontal cortex and nucleus accumbens from electrophysiological …