Nucleus accumbens shell small conductance potassium channels underlie adolescent ethanol exposure-induced anxiety

Alcohol 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

Dopamine D1 and D3 Receptor Polypharmacology in Cocaine Reward and Cocaine Seeking

Background: In the search for efficacious pharmacotherapies to treat cocaine addiction much attention has been given to agents targeting D1 or D3 receptors because of the involvement of these receptors in cocaine-related behaviors. D1 and D3 receptor partial agonists and antagonists have been shown to reduce cocaine reward, reinstatement of cocaine seeking and conditioned place preference (CPP) in rodents and non-human primates. However, translation of these encouraging results with selective D1 or D3 receptor agents has been limited due to a number of factors including toxicity, poor pharmacokinetic properties and extrapyramidal and sedative side effects. Purpose: Given the role of D1 and D3 receptors in cocaine-related behaviors and the urgent need for effective anti-cocaine treatments, it is important that we continue to pursue new pharmacological approaches such as the combinations of compounds that have differential functions at multiple dopamine receptors. The aims of this dissertation were to evaluate the effects of the novel strategy of simultaneous treatments with a D3 receptor antagonist (NGB 2904) and D1 receptor partial agonist (SKF 77434) in animal models of drug addiction, including cue-induced reinstatement of cocaine seeking, cocaine conditioned place preference (CPP) and cocaine self-administration in rats. Methods: In the reinstatement experiment, rats underwent cocaine self-administration training followed by extinction and a cue-induced reinstatement test. Prior to the reinstatement test rats were treated with one of several doses of NGB 2904, SKF 77434 or the combination of the two and their lever presses were measured. In the CPP experiment rats were conditioned to experience cocaine in one compartment of a CPP apparatus and saline in the other. After conditioning rats were treated with the same compounds alone or combined prior to the CPP test. The time spent in the cocaine-paired compartment prior to and after conditioning was measured as an indication of cocaine CPP. In the self-administration experiment, rats were trained to self-administer cocaine under a progressive ratio (PR) schedule of reinforcement. After demonstrating stable baseline break points (BPs) rats were treated repeatedly with NGB 2904 or SKF 77434 alone or the combination of the two. Results: The co-administration of NGB 2904 and SKF 77434, at doses which when administered individually produced no significant effects, prior to reinstatement or CPP tests significantly reduced lever pressing and time spent in the cocaine-paired environment, suggesting synergistic effects of the combined compounds on their abilities to reduce cocaine seeking. When administered to rats self-administering cocaine under a PR schedule of reinforcement doses of NGB 2904 which were ineffective alone significantly potentiated the break point-reducing effects of SKF 77434. Conclusions: The results of this study indicate that the combined treatment with a D1 receptor partial agonist and D3 receptor antagonist produces robust decreases in cocaine seeking and reward. These effects provide insight into a novel therapeutic approach to treat cocaine addiction

PART-TIME FARMERS IN POLAND

^,he^e is a considerable number of private smallholdings in Poland where individual members of the family are employed outside the farm while at the same time continuing to do some farm work. This combination of two activities will remain m Existence until the farms can ensure for the families living on them a socially acceptable standard of living or until ways are opened for the transition of these inhabitants into non-agricultural activities. According to the 1970 census, 35% of the active population and 30% of the heads of rural families in Poland were permanently employed outside agriculture. The income earned by them in jobs outside agriculture exceeded the total accumulation of peasant smallholdings. The author distinguishes three main groups of part-time farmers: (a) peasants/workers with farms chiefly exceeding 2 hectares in area, (b) workers/peasants with farms between 0.5 and 2 hectares, (c) workers with garden plots who mainly live from income earned in non- -agricultural activities. Gradually most of the part-time farmers base their subsistence on a non-agricultural activity while their farms turn into garden plots. As regards the effect af this part-time agriculture on the country’s agricultural production the author states that part-time farms with up to 2 hectares of land have a higher average output per hectare than have purely agricultural ones; that medium-sized farms of both categories have approximately the same output per hectare; and that on larger smallholdings productivity ih higher in the case of purely agricultural households. The development of socialist relations and the transformation of the Polish society as a whole have led to the formation of a comparatively peasant class, a decline of smallbourgeois tendencies among the peasantry, and an increase in the number of workers/peasants which tends to strengthen the federation of workers and peasants. Peasants/workers live on the periphery of the traditional rural and urban cultures, with elements of urban culture growing and those of rural culture weakening. Peasants/workers have a much easier access to the achievements of urban civilization than have peasants, and they are more inclined to accept the values of urban life than are peasants. However, part-time agriculture also has adverse effects on the social development of rural areas: the old rural culture is disappearing at a faster rate than is urban culture spreading. Moreover, it is usually the less valuable elements of mass culture which spread to the rural areas at the expense of the more valuable folk culture. This results in an unwanted cultural disequilibrium which must be overcome. In the view of the author the problem of peasants/workers can be solved gradually by making possible their full transition into non-agricultural jobs. This transition of peasants/workers into non-agricultural activities ought to proceed as part of an integral plan for the spatial organization of the country, i. e. through the development of a planned network of rural and urban settlements. In the concluding part of his article the author discusses in greater detail various measures for solving the problem of peasants/workers along these lines

Ten-year immune persistence and safety of the HPV-16/18 AS04-adjuvanted vaccine in females vaccinated at 15–55 years of age

Women remain at risk of human papillomavirus (HPV) infection for most of their lives. The duration of protection against HPV-16/18 from prophylactic vaccination remains unknown. We investigated the 10-year immune response and long-term safety profile of the HPV-16/18 AS04-adjuvanted vaccine (AS04-HPV-16/18 vaccine) in females aged between 15 and 55 years at first vaccination. Females who received primary vaccination with three doses of AS04-HPV-16/18 vaccine in the primary phase-III study (NCT00196937) were invited to attend annual evaluations for long-term immunogenicity and safety. Anti-HPV-16/18 antibodies in serum and cervico-vaginal secretions (CVS) were measured using enzyme-linked immunosorbent assay (ELISA). Serious adverse events (SAEs) were recorded throughout the follow-up period. Seropositivity rates for anti-HPV-16 remained high (≥96.3%) in all age groups 10 years after first vaccination. It was found that 99.2% of 15–25-year olds remained seropositive for anti-HPV-18 compared to 93.7% and 83.8% of 26–45-year olds and 45–55-year olds, respectively. Geometric mean titers (GMT) remained above natural infection levels in all age groups. Anti-HPV-16 and anti-HPV-18 titers were at least 5.3-fold and 3.1-fold higher than titers observed after natural infection, respectively, and were predicted to persist above natural infection levels for ≥30 years in all age groups. At Year 10, anti-HPV-16/18 antibody titers in subjects aged 15–25 years remained above plateau levels observed in previous studies. Correlation coefficients for antibody titers in serum and CVS were 0.64 (anti-HPV-16) and 0.38 (anti-HPV-18). This study concluded that vaccinated females aged 15–55 years elicited sustained immunogenicity with an acceptable safety profile up to 10 years after primary vaccination, suggesting long-term protection against HPV

Differential Alterations of Insular Cortex Excitability after Adolescent or Adult Chronic Intermittent Ethanol Administration in Male Rats

Adolescent 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

Contrasting Effects of Adolescent and Early-Adult Ethanol Exposure on Prelimbic Cortical Pyramidal Neurons

Background: 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

Aberrations in Incentive Learning and Responding to Heroin in Male Rats After Adolescent or Adult Chronic Binge-Like Alcohol Exposure

Background 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

Adult hippocampal neurogenesis as a target for cocaine addiction: a review of recent developments

Author manuscriptBasic research in rodents has shown that adult hippocampal neurogenesis (AHN) plays a key role in neuropsychiatric disorders that compromise hippocampal functioning. The discovery that dependence-inducing drugs regulate AHN has led to escalating interest in the potential involvement of AHN in drug addiction over the last decade, with cocaine being one of the most frequently investigated drugs. This review argues that, unlike other drugs of abuse, preclinical evidence does not, overall, support that cocaine induces a marked or persistent impairment in AHN. Nevertheless, experimental reduction of AHN consistently exacerbates vulnerability to cocaine. Interestingly, preliminary evidence suggests that, on the contrary, increasing AHN might help both to prevent and treat addiction.This study was funded by grants from the Spanish Ministry of Economy and Competitiveness (MINECO, Agencia Estatal de Investigación) cofounded by the European Regional Development Fund -AEI/FEDER, UE- (‘Jóvenes Investigadores grant’ PSI2015-73156-JIN to E.C.O.; and PSI2017-82604R to L.J.S.)

Role of nucleus accumbens core but not shell in incubation of methamphetamine craving after voluntary abstinence

We recently introduced an animal model to study incubation of drug craving after prolonged voluntary abstinence, mimicking the human condition of relapse after successful contingency management treatment. Here we studied the role of the nucleus accumbens (NAc) in this model. We trained rats to self-administer a palatable solution (sucrose+maltodextrin 1%, 6 h/day, 6 days) and methamphetamine (6 h/day, 12 days). We then evaluated relapse to methamphetamine seeking after 1 and 15 days of voluntary abstinence, achieved via a discrete choice procedure between the palatable solution and methamphetamine (14 days). We used RNAscope in-situ hybridization to quantify the co-labeling of the neuronal activity marker Fos, and dopamine Drd1- and Drd2-expressing medium spiny neurons (MSNs) in NAc core and shell during the incubation tests. Next, we determined the effect of pharmacological inactivation of NAc core and shell by either GABAA and GABAB agonists (muscimol+baclofen, 50+50 ng/side), Drd1-Drd2 antagonist (flupenthixol, 10 µg/side) or the selective Drd1 or Drd2 antagonists (SCH39166 1.0 µg/side or raclopride 1.0 µg/side) during the relapse tests. Incubated methamphetamine seeking after voluntary abstinence was associated with a selective increase of Fos expression in the NAc core, but not shell, and Fos was co-labeled with both Drd1- and Drd2-MSNs. NAc core, but not shell, injections of muscimol+baclofen, flupenthixol, SCH39166, and raclopride reduced methamphetamine seeking after 15 days of abstinence. Together, our results suggest that dopamine transmission through Drd1 and Drd2 in NAc core is critical to the incubation of methamphetamine craving after voluntary abstinence