Electronic cigarette (ECIG) users can manipulate several device features including liquid nicotine concentration (mg/ml) and heating coil resistance (Ohms). One class of ECIG models, called “sub-Ohm” devices, use coils with a resistance of < 1 Ohms, lower than those observed in conventional ECIGs (e.g., ≥ 1.5 Ohms). Increasing voltage or decreasing coil resistance increases device power. Given that ECIG coil resistance and liquid nicotine concentration have not been manipulated systematically and simultaneously in clinical laboratory studies, the influence of these factors on ECIG acute effects remain unclear. The primary purpose of this study was to examine the influence of coil resistance and liquid nicotine concentration on nicotine delivery, heart rate (HR), subjective effects, puff topography, and liquid consumption. Thirty-two experienced ECIG users completed four independent laboratory sessions that differed by coil resistance (0.5Ohm or 1.5Ohm ) and liquid nicotine concentration (3 or 8 mg/ml). In each session, participants used a 4.5 V “Kanger SUBOX” loaded with 3.5 ml ECIG liquid in a 10-puff directed and 60-minute ad libitum bout. Nicotine delivery was greatest when using 8 mg+0.5Ohm combination and lowest when using the 3 mg/ml+1.5Ohm combination and HR followed a similar pattern. Abstinence symptom suppression was most pronounced for the 8 mg+0.5Ohm combination and least pronounced for the 3 mg/ml+1.5Ohm combination. Participants provided the highest ratings for pleasantness, satisfaction, and liking of harshness/irritancy and throat hit sensations for the 3 mg+0.5Ohm combination. Overall, use of ECIGs filled with 3 mg/ml nicotine concentration resulted in longer/larger puffs, increased puff frequency, and greater consumption of ECIG liquid. ECIG coil resistance, liquid nicotine concentration, and user puff topography, all of which influence ECIG nicotine delivery, should be considered together when making regulatory decisions aimed at protecting public health.

The effects of cannabinoids in reducing somatic signs of opioid withdrawal have been known for some time. In morphine dependent rodents, opioid withdrawal following precipitation with the mu opioid antagonist naloxone elicits robust withdrawal behaviors including jumps, paw flutters, head shakes, diarrhea and weight loss. Delta-9-tetrahydrocannabinol has been shown to reduce this opioid withdrawal in mice via activation of the cannabinoid type-1 (CB1) receptor and recently it has been shown that inhibition of the catabolic enzymes for endocannabinoids also reduce somatic signs of opioid withdrawal. Specifically, inhibition the enzyme fatty acid amide hydrolase (FAAH), the catabolic enzyme for the endocannabinoid N-arachidonoylethanolamide (AEA; anandamide) or inhibition of the enzyme monoacylglycerol lipase (MAGL), the catabolic enzyme for the endocannabinoid 2-arachindonoylglycerol (2-AG) has been shown to reduce opioid withdrawal in mice. However, FAAH inhibition only reduced a subset of withdrawal signs in mice and full MAGL inhibition which maximally reduced somatic withdrawal signs has been shown to produce THC-like effects and dependence potential. Additionally, the effects of endocannabinoid catabolic inhibitors on other aspects of withdrawal, such as the negative motivational effects, are not known. The objectives of this dissertation were to 1) assess the efficacy of dual inhibition of FAAH and MAGL on somatic signs of opioid withdrawal and 2) determine whether these treatments would produce cannabimimetic effects (hypomotility, catalepsy, antinociception and hypothermia); 3) develop other behavioral assays of opioid withdrawal; and 4) determine if endocannabinoid catabolic inhibitors would reduce the acquisition of opioid withdrawal induced conditioned place avoidance (CPA) as a measure of the negative motivational consequences of opioid withdrawal. We found that full inhibition of FAAH with the selective inhibitor PF-3845 and partial inhibition of MAGL with the selective inhibitor JZL184 reduced withdrawal-related jumps and the expression of diarrhea to a greater degree than either inhibitor alone and these effects were shown to be CB1 mediated. Additionally, we tested the novel dual FAAH/MAGL inhibitor SA-57 which has greater potency at inhibiting FAAH over MAGL and found that it similarly reduced withdrawal signs at doses that only partially elevated 2-AG while fully elevating AEA; furthermore, SA-57 did not produce cannabimimetic effects at these doses. We next assessed the effects of morphine withdrawal in five behavioral assays: marble burying, novelty-induced hypophagia, the light/dark box, a novel procedure developed to assess “escape behavior” and the CPA procedure. From these studies we selected the CPA procedure to further evaluate the effects of endocannabinoid catabolic inhibitors to determine their ability to reduce the negative motivational aspect of opioid withdrawal. We found that naloxone (0.056 mg/kg) produced robust CPA in morphine-pelleted, but not placebo-pelleted, mice and that this dose elicited minimal somatic withdrawal signs. Morphine pretreatment was shown to block withdrawal CPA and withdrawal jumping in mice while clonidine only blocked withdrawal CPA and these served as positive controls. We found that THC, JZL184, and SA-57 significantly reduced the percentage of mice that jumped during the conditioning session, demonstrating that these treatments blocked the somatic signs of withdrawal. However, none of these treatments significantly affected acquisition of the withdrawal CPA. These studies suggest that dual inhibition of FAAH/MAGL has enhanced effects on attenuating withdrawal-related jumps and diarrhea, but not the negative motivational aspects of morphine withdrawal as inferred by the Pavlovian CPA experiments.

Electronic cigarettes (ECIGs) aerosolize an often nicotine-containing solution for user inhalation. ECIG nicotine delivery may depend on liquid nicotine concentration and user puffing behavior (topography). This study examined the relationship among liquid nicotine concentration, puff topography, and plasma nicotine concentration. Thirty-three ECIG-experienced and 31 ECIG-naïve individuals completed four laboratory sessions that differed by ECIG liquid nicotine concentration (0, 8, 18, or 36 mg/ml). A 3.3 volt “eGo” ECIG battery attached to a 1.5 Ohm dual coil “cartomizer” filled with 1 ml of 70% propylene glycol/30% vegetable glycerin nicotine liquid was used in two ECIG-bouts (10 puffs; 30 s IPI). Plasma nicotine concentration, puff topography, and HR were evaluated. Some ECIG/liquid combinations can deliver physiologically active doses of nicotine to users, and nicotine delivery depends on liquid nicotine concentration and user puffing behavior. Liquid contents, device characteristics, and user behavior should be considered when regulating ECIGs.

Mu-opioid receptor (MOR) agonists are effective agents for pain management, but are also limited by a number of undesirable effects. One approach to enhance the therapeutic effects and minimize the undesirable effects of MOR agonists may be to combine MOR agonists with an adjunct targeting a different receptor system. This targeted medical approach, known as “combination therapy”, aims to augment the desired effects of the MOR agonist (i.e. antinociception) and/or diminish the undesirable deleterious side effects of the MOR agonist. This dissertation investigated the utility of this approach in an assay of thermal nociception and schedule-controlled responding in male rhesus monkeys with three aims. One aim determined the utility of N-methyl D-aspartate (NMDA) receptor antagonists to selectively enhance MOR agonist antinociception. A second identified the pharmacological determinants of antinociceptive interactions between a nociceptin opioid peptide (NOP) receptor agonist and MOR agonists. A third aim investigated the potential for fixed-proportion mixtures of a competitive MOR antagonist and MOR agonist to manipulate antinociceptive efficacy. Experimental results did not support the utility of NMDA antagonists as adjuncts to selectively enhance MOR agonist antinociception. Furthermore, the antinociceptive interactions between a NOP agonist and MOR agonists were modest and occurred under a narrow range of conditions. Finally, fixed proportion MOR antagonist-agonist mixtures were effective in manipulating antinociceptive in vivo efficacy. In conclusion, this dissertation does not provide strong empirical evidence that a combination therapy approach will result in clinically effective and selective enhancement of MOR agonist analgesia. The dissertation concludes with proposed strategies and novel preclinical methods to enhance preclinical-to-clinical translation of effective candidate analgesics.

Tryptophan depletion is a non-pharmacological and non-invasive method extensively used to investigate the role of serotonin (5-hydroxytryptamine in humans and animals. The method is based on reducing the availability of the essential amino acid tryptophan, the dietary serotonin precursor. As a precursor of serotonin, L-Tryptophan has a key role in the regulation of many physiological processes and, inter alia, in the pathology and pathophysiology of neuropsychiatric disorders and diseases. Despite the fact, that the method of tryptophan depletion has been applied in many experimental studies, the exact mechanism, by which tryptophan depletion inducted neurophysiological effects, remain unclear. Also, the protentional use of this method together with other drug coadministration has not been explored in detail yet. In this thesis, the most possible mechanisms of tryptophan depletion are discussed. Biochemical and behavioural effects of low dose of dizocilpine (0.1 mg/kg and 0.15 mg/kg) in animal model of tryptophan depletion are investigated as well. And finally, effects of administration of allopregnanolone and tacrine in model of tryptophan depletion with coadministration of MK-801 are studied. The results show that acute tryptophan depletion with prior starvation, not chronic depletion, caused...

Yes / Here we describe for the first time the distinctive pharmacological profile for IRL752, a new phenyl-pyrrolidine derivative with regio-selective CNS transmission-enhancing properties. IRL752 (3.7-150 μmol/kg, s.c.) was characterised through extensive in vivo studies, using behavioural, tissue neurochemical and gene expression, as well as microdialysis methods. Behaviourally, the compound normalised tetrabenazine-induced hypoactivity, while unable to stimulate basal locomotion in normal animals or to either accentuate or reverse hyperactivity induced by amphetamine or MK-801. IRL752 induced but minor changes in monoaminergic tissue neurochemistry across NA- and DA-dominated brain regions. The expression of neuronal activity-, plasticity-, and cognition-related IEGs (immediate early genes) however increased by 1.5- to 2-fold. Furthermore, IRL752 dose-dependently enhanced cortical catecholamine dialysate output to 600-750% above baseline, while striatal DA remained unaltered and NA rose to ~250%; cortical and hippocampal dialysate ACh increased to ~250% and 190% above corresponding baseline, respectively. In line with this cortically preferential transmission-promoting action, the drug was also pro-cognitive in the novel object recognition and reversal learning tests. In vitro neurotarget affinity and functional data, coupled to drug exposure support the hypothesis that 5‑HT7 receptor and α2(C)-adrenoceptor antagonism are key contributors to the in vivo efficacy and original profile of IRL752. The cortical-preferring facilitatory impact on catecholamine (and ACh) neurotransmission, along with effects on IEG expression and cognition-enhancing features, are in line with the potential clinical usefulness of IRL752 in conditions where these aspects may be dysregulated, such as in axial motor and cognitive deficits in Parkinson's Disease.

Among children diagnosed with acute lymphoblastic leukemia (ALL) and given chemotherapy-only treatment, 40-70% of survivors experience neurocognitive impairment. Psychostimulants such as methylphenidate are becoming popular medications for treating these deficits in childhood cancer survivors. However, little is known about the outcome of prescribing stimulants to this population. In the research reported here, a novel preclinical mouse model of ALL treatment was developed and used to investigate the effects of early exposure to methotrexate (MTX) and cytarabine (Ara-C) on learning and memory, and the outcome of treating these deficits using a number of different stimulants. Mouse pups were treated on postnatal day (PND) 14, 15, and 16 with saline, MTX, Ara-C, or two combinations of MTX and Ara-C. At PND 35, significant impairments on learning and memory as measured by autoshaping and novel object recognition were found. Mild deficits were observed in a novel conditional discrimination task, which suggests that extensive training may ameliorate learning impairments. MTX and Ara-C treated mice also exhibited sensitivity to the rewarding and stimulatory properties of amphetamine and methylphenidate, suggesting that typical psychostimulants may become more potent following early chemotherapeutic treatment. In contrast, no increase in drug reward following early exposure to MTX and Ara-C was found for an alternative treatment with possible neuroprotective effects, atomoxetine. These findings were further supported by converging evidence that chemotherapy-treated mice displayed increased novelty-seeking. In addition, a greater percentage of MTX and Ara-C treated mice acquired cocaine self-administration, and maintained a higher number of infusions per session. Overall, these findings highlight the usefulness of preclinical models to examine the developmental effects of early exposure to chemotherapeutic agents on future learning, possible models of cognitive remediation, and the consequences of treating impairments using typical psychostimulant medications. / Psychology

Cancer is the second most common cause of death in the world. One of the objectives of this thesis is to biologically evaluate a series of anti-cancer polymeric aromatic/heterocyclic bis-sulfonamides and pyridinium sulfonamides which were synthesized from three established aminosulfonamide carbonic anhydrase (CA, EC 4.2.1.1) inhibitor pharmacophores. Testing of these novel inhibitors and their precursors against a panel of membrane-bound CA isoforms, including tumor-overexpressed CA IX and XII and cytosolic isozymes, identified nanomolar-potent inhibitors against both classes and several compounds with medium isoform selectivity. In the case of pyridinium sulfonamides we used complexes of the inhibitors with cyclodextrins or sulfocalixarene to enhance aqueous solubility for biological testing. The ability of CA inhibitors to kill tumor cells overexpressing CA IX and XII was tested under normoxic and hypoxic conditions, using 2D and 3D in vitro cellular models. The study identified a nanomolar potent PEGylated bis-sulfonamide CA inhibitor (25), as well as cyclodextrin and sulfocalixarenes complexes, which were able to significantly reduce the viability of colon HT-29, breast MDA-MB231, and ovarian SKOV-3 cancer cell lines, thus revealing the potential of polymer conjugates in CA inhibition and cancer treatment. As a different disease state yet still a concern, cognitive dysfunction markedly impacts patients with a host of psychiatric conditions including attention deficit hyperactivity disorder, autism spectrum disorder, drug addiction, schizophrenia, depression, bipolar disorder, obsessive-compulsive disorder, and of course, Parkinson’s and Alzheimer’s diseases and other types of dementia. Another objective of this thesis was to profile several series of bis-imidazoles for physicochemical, in-vitro and in-vivo properties as potential memory and learning enhancers (nootropics). Biological testing on eight isozymes of carbonic anhydrase (CA) present in the human brain revealed compounds with nanomolar potency against at least one membrane bound, cytosolic or mitochondrial CA isozymes, combined with good physicochemical properties. We also identified lead compounds with the ability to rescue experimental animals from drug-induced memory deficits, using an optimized Novel Object Recognition Task (NORT) procedure. / Pharmaceutical Sciences

Benzodiazepínicos são as drogas lícitas mais vendidas no Brasil - certa de 50 milhões de brasileiros fazem uso diário desse tipo de droga. É clara a importância de se conhecer os efeitos que essas drogas podem ter sobre o comportamento. Existem diversas lacunas no conhecimento de como afetam diferentes aspectos do comportamento operante, entretanto. Especificamente, o efeito do tratamento sobre o responder por reforçadores condicionados tem sido uma área pouco explorada. O presente estudo se propôs a investigar os efeitos do tratamento com bromazepam sobre o responder por um estímulo condicionado e um incondicionado, em dois esquemas complementares, razão progressiva e segunda ordem. Foram conduzidos três experimentos. Experimento I: 9 ratas de aproximadamente 9 meses de idade foram submetidas à um esquema de razão progressiva, tendo um composto de luz (LUZ) e solução de sacarose (SAC) como consequência; uma vez obtida uma linha de base foi iniciado tratamento com 1 mg/kg de bromazepam em 4 dos sujeitos (BRO) e salina (VEI) nos demais. Após 28 dias, foi removida SAC. Após 8 dias, foi removida também LUZ. Ocorreram então 5 sessões de extinção. Foi observada uma redução no responder durante o tratamento em BRO. O tratamento não apresentou efeitos adicionais durante a fase de remoção das consequências. Experimento II: replicação do I utilizando 18 machos de aproximadamente 3 meses de idade e com uma entrefase de adaptação ao procedimento de injeção. O tratamento levou ao aumento do responder em BRO (F2,23=8,13; p=0,001), porém não trouxe diferenças após a remoção das consequências. Experimento III: 20 ratos machos de 3 meses de idade foram submetidos à duas fases experimentais: manutenção (no qual, por quatro dias, eram expostos à esquemas de segunda ordem de Razão/Intervalo com a duração do intervalo crescente a cada sessão (FI 2min (FR5:luz); FI 5min(FR5:luz); FI10min(FR5:luz) e FI20min(FR5:luz), e teste (T1 FI20min(FR5luz)), T2 FR5 e T3 FI20min). As fases de manutenção tinham por objetivo estabelecer e fortalecer a relação LUZ/SAC. Responder para VEI se mostrou estável nas fases teste, enquanto foi observada uma redução em T3 para BRO. Os resultados indicam que BRO teve efeito de modular o responder pelo reforçador incondicionado em todas as situações experimentais, interagindo com o esquema vigente e outras variáveis experimentais como sexo. Não foi observado, entretanto, efeito específico sobre a eficácia de reforçadores condicionados / Benzodiazepines are the most sold of legal drugs in Brazil about 50 million Brazilians use this kind of drug on a daily basis. The importance of knowing the effects of these drugs on behavior is clear. There are several gaps in the knowledge of these drugs affect operant behavior, however. Specifically, the effect of treatment on the responding for conditioned reinforcements is an area that has seldom been investigated. The present study proposed to investigate the effects of bromazepam treatment on the responding for a conditioned and an unconditioned stimulus, in two complementary schedules, namely, progressive ratio and second order. Three experiments were held. Experiment I: 9 female rats of approximately 9 months of age underwent a progressive ratio schedule, with a sucrose solution (SUC) and a light presentation (LIGHT) as concomitant consequences. Once baseline was stablished, treatment with 1mg/kg bromazepam was started for 4 subjects (BRO). The remaining received saline (VEI). After 29 days, SAC was removed. After 8 days, LIGHT was also removed. Then 5 sessions of extinction took place. Lower responding was observed in BRO. Treatment did not further effect behavior in the remaining experimental stages (consequence removal). Experiment II: pilot replication using 18 male rats and including a stage of habituation to the injection procedure. Treatment incurred in the increase of responding for BRO (F2,23=8.13; p=0.001), but had no further effects on the subsequent stages. Experiment III: 20 male rats underwent two experimental stages: maintenance (for four days the animal underwent second order schedules composed of a Ratio and an Interval component, in which the interval increased with each session ( (FI 2min(FR5:light); FI 5min(FR5light); FI10min(FR5light) E FI20min(FR5light) and test (T1 FI20min(FR5light)), T2 FR5 and T3 FI20min). Maintenance stages were intended to stablish and strengthen the LIGHT/SUC relation. VEI responded in a stable manner in all test stages, while BRO showed a reduction in responding in T3. Overall results indicate BRO was able to modulate responding for the unconditioned reinforcer in all experimental situations, interacting with other variables such as schedule and sex. No particular effect was found on the efficacy of the conditioned stimulus, however

Benzodiazepínicos são as drogas lícitas mais vendidas no Brasil - certa de 50 milhões de brasileiros fazem uso diário desse tipo de droga. É clara a importância de se conhecer os efeitos que essas drogas podem ter sobre o comportamento. Existem diversas lacunas no conhecimento de como afetam diferentes aspectos do comportamento operante, entretanto. Especificamente, o efeito do tratamento sobre o responder por reforçadores condicionados tem sido uma área pouco explorada. O presente estudo se propôs a investigar os efeitos do tratamento com bromazepam sobre o responder por um estímulo condicionado e um incondicionado, em dois esquemas complementares, razão progressiva e segunda ordem. Foram conduzidos três experimentos. Experimento I: 9 ratas de aproximadamente 9 meses de idade foram submetidas à um esquema de razão progressiva, tendo um composto de luz (LUZ) e solução de sacarose (SAC) como consequência; uma vez obtida uma linha de base foi iniciado tratamento com 1 mg/kg de bromazepam em 4 dos sujeitos (BRO) e salina (VEI) nos demais. Após 28 dias, foi removida SAC. Após 8 dias, foi removida também LUZ. Ocorreram então 5 sessões de extinção. Foi observada uma redução no responder durante o tratamento em BRO. O tratamento não apresentou efeitos adicionais durante a fase de remoção das consequências. Experimento II: replicação do I utilizando 18 machos de aproximadamente 3 meses de idade e com uma entrefase de adaptação ao procedimento de injeção. O tratamento levou ao aumento do responder em BRO (F2,23=8,13; p=0,001), porém não trouxe diferenças após a remoção das consequências. Experimento III: 20 ratos machos de 3 meses de idade foram submetidos à duas fases experimentais: manutenção (no qual, por quatro dias, eram expostos à esquemas de segunda ordem de Razão/Intervalo com a duração do intervalo crescente a cada sessão (FI 2min (FR5:luz); FI 5min(FR5:luz); FI10min(FR5:luz) e FI20min(FR5:luz), e teste (T1 FI20min(FR5luz)), T2 FR5 e T3 FI20min). As fases de manutenção tinham por objetivo estabelecer e fortalecer a relação LUZ/SAC. Responder para VEI se mostrou estável nas fases teste, enquanto foi observada uma redução em T3 para BRO. Os resultados indicam que BRO teve efeito de modular o responder pelo reforçador incondicionado em todas as situações experimentais, interagindo com o esquema vigente e outras variáveis experimentais como sexo. Não foi observado, entretanto, efeito específico sobre a eficácia de reforçadores condicionados / Benzodiazepines are the most sold of legal drugs in Brazil about 50 million Brazilians use this kind of drug on a daily basis. The importance of knowing the effects of these drugs on behavior is clear. There are several gaps in the knowledge of these drugs affect operant behavior, however. Specifically, the effect of treatment on the responding for conditioned reinforcements is an area that has seldom been investigated. The present study proposed to investigate the effects of bromazepam treatment on the responding for a conditioned and an unconditioned stimulus, in two complementary schedules, namely, progressive ratio and second order. Three experiments were held. Experiment I: 9 female rats of approximately 9 months of age underwent a progressive ratio schedule, with a sucrose solution (SUC) and a light presentation (LIGHT) as concomitant consequences. Once baseline was stablished, treatment with 1mg/kg bromazepam was started for 4 subjects (BRO). The remaining received saline (VEI). After 29 days, SAC was removed. After 8 days, LIGHT was also removed. Then 5 sessions of extinction took place. Lower responding was observed in BRO. Treatment did not further effect behavior in the remaining experimental stages (consequence removal). Experiment II: pilot replication using 18 male rats and including a stage of habituation to the injection procedure. Treatment incurred in the increase of responding for BRO (F2,23=8.13; p=0.001), but had no further effects on the subsequent stages. Experiment III: 20 male rats underwent two experimental stages: maintenance (for four days the animal underwent second order schedules composed of a Ratio and an Interval component, in which the interval increased with each session ( (FI 2min(FR5:light); FI 5min(FR5light); FI10min(FR5light) E FI20min(FR5light) and test (T1 FI20min(FR5light)), T2 FR5 and T3 FI20min). Maintenance stages were intended to stablish and strengthen the LIGHT/SUC relation. VEI responded in a stable manner in all test stages, while BRO showed a reduction in responding in T3. Overall results indicate BRO was able to modulate responding for the unconditioned reinforcer in all experimental situations, interacting with other variables such as schedule and sex. No particular effect was found on the efficacy of the conditioned stimulus, however