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Browsing by Author "Ma, Yao-Ying"
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Item Aberrations in Incentive Learning and Responding to Heroin in Male Rats After Adolescent or Adult Chronic Binge-Like Alcohol Exposure(Wiley, 2020-06) Galaj, Ewa; Barrera, Eddy; Morris, Debra; Ma, Yao-Ying; Ranaldi, Robert; Pharmacology and Toxicology, School of MedicineBackground and purpose: Binge drinking is a serious problem among adolescents and young adults despite its adverse consequences on the brain and behavior. One area that remains poorly understood concerns the impact of chronic intermittent ethanol (CIE) exposure on incentive learning. Methods: Here, we examined the effects of CIE exposure during different developmental stages on conditioned approach and conditioned reward learning in rats experiencing acute or protracted withdrawal from alcohol. Two or 21 days after adolescent or adult CIE exposure, male rats were exposed to pairings of a light stimulus (CS) and food pellets for 3 consecutive daily sessions (30 CS-food pellet pairings per session). This was followed by conditioned approach testing measuring responses (food trough head entries) to the CS-only presentations and by conditioned reward testing measuring responses on a lever producing the CS and on another producing a tone. We then measured behavioral sensitization to repeated injections of heroin (2 mg/kg/d for 9 days). Results: Adolescent and adult alcohol-treated rats showed significantly impaired conditioned reward learning regardless of withdrawal period (acute or prolonged). We found no evidence of changes to conditioned approach learning after adolescent or adult exposure to CIE. Finally, in addition to producing long-term impairments in incentive learning, CIE exposure enhanced locomotor activity in response to heroin and had no effect on behavioral sensitization to heroin regardless of age and withdrawal period. Conclusions: Our work sets a framework for identifying CIE-induced alterations in incentive learning and inducing susceptibility to subsequent opioid effects.Item Amyloid-β oligomers in the nucleus accumbens decrease motivation via insertion of calcium-permeable AMPA receptors(Springer Nature, 2022) Guo, Changyong; Wen, Di; Zhang, Yihong; Mustaklem, Richie; Mustaklem, Basil; Zhou, Miou; Ma, Tao; Ma, Yao-Ying; Pharmacology and Toxicology, School of MedicineIt is essential to identify the neuronal mechanisms of Alzheimer’s Disease (AD)-associated neuropsychiatric symptoms, e.g., apathy, before improving the life quality of AD patients. Here, we focused on the nucleus accumbens (NAc), a critical brain region processing motivation, also known to display AD-associated pathological changes in human cases. We found that the synaptic calcium permeable (CP)-AMPA receptors (AMPARs), which are normally absent in the NAc, can be revealed by acute exposure to Aβ oligomers (AβOs), and play a critical role in the emergence of synaptic loss and motivation deficits. Blockade of NAc CP-AMPARs can effectively prevent AβO-induced downsizing and pruning of spines and silencing of excitatory synaptic transmission. We conclude that AβO-triggered synaptic insertion of CP-AMPARs is a key mechanism mediating synaptic degeneration in AD, and preserving synaptic integrity may prevent or delay the onset of AD-associated psychiatric symptoms.Item Calcium Permeable-AMPA Receptors and Excitotoxicity in Neurological Disorders(Frontiers Media, 2021-08-17) Guo, Changyong; Ma, Yao-Ying; Pharmacology and Toxicology, School of MedicineExcitotoxicity is one of the primary mechanisms of cell loss in a variety of diseases of the central and peripheral nervous systems. Other than the previously established signaling pathways of excitotoxicity, which depend on the excessive release of glutamate from axon terminals or over-activation of NMDA receptors (NMDARs), Ca2+ influx-triggered excitotoxicity through Ca2+-permeable (CP)-AMPA receptors (AMPARs) is detected in multiple disease models. In this review, both acute brain insults (e.g., brain trauma or spinal cord injury, ischemia) and chronic neurological disorders, including Epilepsy/Seizures, Huntington’s disease (HD), Parkinson’s disease (PD), Alzheimer’s disease (AD), amyotrophic lateral sclerosis (ALS), chronic pain, and glaucoma, are discussed regarding the CP-AMPAR-mediated excitotoxicity. Considering the low expression or absence of CP-AMPARs in most cells, specific manipulation of the CP-AMPARs might be a more plausible strategy to delay the onset and progression of pathological alterations with fewer side effects than blocking NMDARs.Item Contrasting Effects of Adolescent and Early-Adult Ethanol Exposure on Prelimbic Cortical Pyramidal Neurons(Elsevier, 2020) Galaj, Ewa; Guo, Changyong; Huang, Donald; Ranaldi, Robert; Ma, Yao-Ying; Pharmacology and Toxicology, School of MedicineBackground: Adolescence and early-adulthood are vulnerable developmental periods during which binge drinking can have long-lasting effects on brain function. However, little is known about the effects of binge drinking on the pyramidal cells of the prelimbic cortex (PrL) during early and protracted withdrawal periods. Methods: In the present study, we performed whole-cell patch clamp recordings and dendritic spine staining to examine the intrinsic excitability, spontaneous excitatory post-synaptic currents (sEPSCs), and spine morphology of pyramidal cells in the PrL from rats exposed to chronic intermittent ethanol (CIE) during adolescence or early-adulthood. Results: Compared to chronic intermittent water (CIW)-treated controls, the excitability of PrL-L5 pyramidal neurons was significantly increased 21 days after adolescent CIE but decreased 21 days after early-adult CIE. No changes of excitability in PrL Layer (L) 5 were detected 2 days after either adolescent or early-adulthood CIE. Interestingly, decreases in sEPSC amplitude and increases in thin spines ratio were detected 2 days after adolescent CIE. Furthermore, decreased frequency and amplitude of sEPSCs, accompanied by a decrease in the density of total spines and non-thin spines were observed 21 days after adolescent CIE. In contrast, increased frequency and amplitude of sEPSCs, accompanied by increased densities of total spines and non-thin spines were found 21 days after early adult CIE. Conclusion: CIE produced prolonged neuronal and synaptic alterations in PrL-L5, and the developmental stage, i.e., adolescence vs. early-adulthood when subjects receive CIE, is a key factor in determining the direction of these changes.Item Differential Alterations of Insular Cortex Excitability after Adolescent or Adult Chronic Intermittent Ethanol Administration in Male Rats(Wiley, 2021-02) Luo, Yi-Xiao; Galaj, Ewa; Ma, Yao-Ying; Pharmacology and Toxicology, School of MedicineAdolescent alcohol drinking, primarily in the form of binge-drinking episodes, is a serious public health concern. Binge drinking in laboratory animals has been modeled by a procedure involving chronic intermittent ethanol (CIE) administration, as compared with chronic intermittent water (CIW). The prolonged effects of adolescent binge alcohol exposure in adults, such as high risk of developing alcohol use disorder, are severe but available treatments in the clinic are limited. One reason is the lack of sufficient understanding about the associated neuronal alterations. The involvement of the insular cortex, particularly the anterior agranular insula (AAI), has emerged as a critical region to explain neuronal mechanisms of substance abuse. This study was designed to evaluate the functional output of the AAI by measuring the intrinsic excitability of pyramidal neurons from male rats 2 or 21 days after adolescent or adult CIE treatment. Decreases in intrinsic excitability in AAI pyramidal neurons were detected 21 days, relative to 2 days, after adolescent CIE. Interestingly, the decreased intrinsic excitability in the AAI pyramidal neurons was observed 2 days after adult CIE, compared to adult CIW, but no difference was found between 2 versus 21 days after adult CIE. These data indicate that, although the AAI is influenced within a limited period after adult but not adolescent CIE, neuronal alterations in AAI are affected during the prolonged period of withdrawal from adolescent but not adult CIE. This may explain the prolonged vulnerability to mental disorders of subjects with an alcohol binge history during their adolescent stage.Item Human Neural Stem Cells in Space Proliferate more than Ground Control Cells: Implications for Long-Term Space Travel(Herald, 2021-04) Shaka, Sophia; Carpo, Nicholas; Tran, Victoria; Ma, Yao-Ying; Karouia, Fathi; Espinosa-Jeffrey, Araceli; Pharmacology and Toxicology, School of MedicineLong-term travel and lengthy stays for astronauts in outer space are imminent. To date, more than 500 astronauts have experienced the extreme conditions of space flight including microgravity and radiation. For the past decade, many studies associated with long-duration spaceflight have shown the recurring occurrence of ophthalmic abnormalities. The reasons of the observed changes in some astronauts remained unclear. However, factors such as the increase in intracranial pressure and fluid shifts are among the top potential contributing elements. Here we report a study that specifically looked at the effect of space environment on the proliferation and physiology of human Neural Stem Cells (NSCs) onboard the International Space Station (ISS) as compared to ground controls. The study revealed that human NSCs proliferated seven times more while in space (SPC) when compared to on Earth (1G) control cultures. We also examined by continuous live imaging the behavior of space flown NSCs upon return to Earth. We found that after space flight, they continued proliferating at the same pace as 1G controls. Interestingly, NSCs flown to space displayed a larger diameter than control cells. These phenomena, increased proliferation while in space and larger cell soma may contribute to intracranial hypertension found in astronauts, representing a risk factor and potential limitation to long duration space missions such as travelling to the Moon or Mars. In addition, NSCs are essential to maintain Central Nervous System (CNS) function, as they are the basis for the regeneration of CNS cell populations in health and disease.Item Increased Excitability of Pyramidal Neurons in the Secondary Motor Cortex Enhances Cocaine-Seeking(2023-09) Huang, Donald; Atwood, Brady K.; Baucum, AJ; Hopf, Woody; Ma, Yao-Ying; Sheets, Patrick L.Cocaine addiction is a brain disorder characterized by chronic relapse. Although drug-seeking behaviors have been recognized to be associated with relapse, the role of the motor cortex, including the primary (M1) and secondary (M2) motor cortex, which are functionally important mediators of complex behaviors remains unclear in addiction. Here we use a rat cocaine intravenous self-administration (IVSA) model to investigate the intrinsic excitability of pyramidal neurons in the medial prefrontal cortices and motor cortices during withdrawal. Cocaine IVSA-trained rats performed a cocaine-seeking test on withdrawal day (WD) 1 or WD 45. Relative to WD 1 an increase in cocaineseeking was detected on WD 45. Whole-cell patch clamp recordings revealed an increase in intrinsic excitability in pyramidal neurons in Layer 2 of the secondary motor cortex (M2-L2) in cocaine trained rats on WD 45. Using a pharmacological approach, bath application of GABAA receptor agonist, muscimol, dosedependently (0.1 mM, 0.3 mM, and 1.0 mM) decreased the excitability of M2-L2 pyramidal neurons in cocaine IVSA-trained rats on WD 45. Pharmacological inactivation of M2-L2 by bilateral intra-M2 injection of muscimol (324 ng/1.0 μl) attenuated cocaine-seeking on WD 45. A chemogenetic approach was used to validate that M2-L2 pyramidal neurons play a contributing role in the increase in cocaine-seeking, a microinjection of rAAV5-CaMKIIa-hM4di-mCherry was performed to express Gi-DREADD receptors on M2-L2 pyramidal neurons. Activating Gi-DREADD with an intraperitoneal injection of compound 21 on WD 45 attenuated cocaine-seeking. To elucidate the mechanism that contributes to the increased excitability of M2-L2 pyramidal neurons, an analysis of the action potential kinetics revealed that calcium-activated small conductance potassium (SK) channel-mediated medium afterhyperpolarization amplitude decreased in cocaine vs. saline IVSA-trained rats on WD 45. SK channel activation by 1-EBIO (300 μm) increased the medium afterhyperpolarization amplitude and decreased the excitability of M2-L2 pyramidal neurons in cocaine IVSA-trained rats. Furthermore, intra-M2 injection of 1-EBIO on WD 45 attenuated cocaine-seeking. These experiments suggest that cocaine IVSA-training-induced persistent changes in M2-L2 pyramidal neurons' intrinsic excitability contributes to enhanced cocaine-seeking. Our results provide evidence targeting the SK channels in the superficial layer for M2 could be an important therapeutic approach for preventing cocaine relapse.Item KDM2A Deficiency in the Liver Promotes Abnormal Liver Function and Potential Liver Damage(MDPI, 2023-09-27) Martin, Matthew; Motolani, Aishat; Kim, Hyeong-Geug; Collins, Amy M.; Alipourgivi, Faranak; Jin, Jiamin; Wei, Han; Wood, Barry A.; Ma, Yao-Ying; Dong, X. Charlie; Mirmira, Raghavendra G.; Lu, Tao; Pharmacology and Toxicology, School of MedicineDysregulation of metabolic functions in the liver impacts the development of diabetes and metabolic disorders. Normal liver function can be compromised by increased inflammation via the activation of signaling such as nuclear factor (NF)-κB signaling. Notably, we have previously identified lysine demethylase 2A (KDM2A)—as a critical negative regulator of NF-κB. However, there are no studies demonstrating the effect of KDM2A on liver function. Here, we established a novel liver-specific Kdm2a knockout mouse model to evaluate KDM2A’s role in liver functions. An inducible hepatic deletion of Kdm2a, Alb-Cre-Kdm2afl/fl (Kdm2a KO), was generated by crossing the Kdm2a floxed mice (Kdm2afl/fl) we established with commercial albumin-Cre transgenic mice (B6.Cg-Tg(Alb-cre)21Mgn/J). We show that under a normal diet, Kdm2a KO mice exhibited increased serum alanine aminotransferase (ALT) activity, L-type triglycerides (TG) levels, and liver glycogen levels vs. WT (Kdm2afl/fl) animals. These changes were further enhanced in Kdm2a liver KO mice in high-fat diet (HFD) conditions. We also observed a significant increase in NF-κB target gene expression in Kdm2a liver KO mice under HFD conditions. Similarly, the KO mice exhibited increased immune cell infiltration. Collectively, these data suggest liver-specific KDM2A deficiency may enhance inflammation in the liver, potentially through NF-κB activation, and lead to liver dysfunction. Our study also suggests that the established Kdm2afl/fl mouse model may serve as a powerful tool for studying liver-related metabolic diseases.Item Limited versus extended cocaine intravenous self‐administration: Behavioral effects and electrophysiological changes in insular cortex(Wiley, 2021-02) Luo, Yi-Xiao; Huang, Donald; Guo, Changyong; Ma, Yao-Ying; Pharmacology and Toxicology, School of MedicineAims: Limited vs extended drug exposure has been proposed as one of the key factors in determining the risk of relapse, which is the primary characteristic of addiction behaviors. The current studies were designed to explore the related behavioral effects and neuronal alterations in the insular cortex (IC), an important brain region involved in addiction. Methods: Experiments started with rats at the age of 35 days, a typical adolescent stage when initial drug exposure occurs often in humans. The drug-seeking/taking behaviors, and membrane properties and intrinsic excitability of IC pyramidal neurons were measured on withdrawal day (WD) 1 and WD 45-48 after limited vs extended cocaine intravenous self-administration (IVSA). Results: We found higher cocaine-taking behaviors at the late withdrawal period after limited vs extended cocaine IVSA. We also found minor but significant effects of limited but not extended cocaine exposure on the kinetics and amplitude of action potentials on WD 45, in IC pyramidal neurons. Conclusion: Our results indicate potential high risks of relapse in young rats with limited but not extended drug exposure, although the adaptations detected in the IC may not be sufficient to explain the neural changes of higher drug-taking behaviors induced by limited cocaine IVSA.Item Nucleus accumbens shell small conductance potassium channels underlie adolescent ethanol exposure-induced anxiety(Springer Nature, 2019-10) Shan, Lili; Galaj, Ewa; Ma, Yao-Ying; Pharmacology and Toxicology, School of MedicineAlcohol use typically begins in adolescence, increasing the likelihood of adult mental disorders such as anxiety. However, the cellular mechanisms underlying the consequences of adolescent alcohol exposure as well as the behavioral consequences remain poorly understood. We examined the effects of adolescent or adult chronic intermittent ethanol (CIE) exposure on intrinsic excitability of striatal medium-sized spiny neurons (MSNs) and anxiety levels. Rats underwent one of the following procedures: (1) light-dark transition (LDT) and open-field (OF) tests to evaluate anxiety levels and general locomotion; (2) whole-cell patch clamp recordings and biocytin labeling to assess excitability of striatal MSNs, as well as morphological properties; and (3) western blot immunostaining to determine small conductance (SK) calcium-activated potassium channel protein levels. Three weeks, but not 2 days, after CIE treatment, adolescent CIE-treated rats showed shorter crossover latency from the light to dark side in the LDT test and higher MSN excitability in the nucleus accumbens shell (NAcS). Furthermore, the amplitude of the medium afterhyperpolarization (mAHP), mediated by SK channels, and SK3 protein levels in the NAcS decreased concomitantly. Finally, increased anxiety levels, increased excitability, and decreased amplitude of mAHP of NAcS MSNs were reversed by SK channel activator 1-EBIO and mimicked by the SK channel blocker apamin. Thus, adolescent ethanol exposure increases adult anxiety-like behavior by downregulating SK channel function and protein expression, which leads to an increase of intrinsic excitability in NAcS MSNs. SK channels in the NAcS may serve as a target to treat adolescent alcohol binge exposure-induced mental disorders, such as anxiety in adulthood.