Prosocial Behavior as a Stress Moderator: The Physiological and Psychological Components

Stress is a major part of everyday life for the majority of people, especially college students. Stress has a physiological response and serves an important purpose in the body. If an individual does not take the proper measures to reduce stress and it continues for long periods of time, the outcome can be damaging to the stressed individual. Stress can cause problems both physically and mentally. There are many different ways to reduce stress and to counteract the damage that stress can cause on the body. Prosocial behavior is an action that elevates others’ needs over an individual’s needs. Studies have been completed to see if this type of behavior is capable of reducing stress. This coping mechanism appears to be effective because the physiological effects and psychological effects that prosocial behavior has on the body are opposite of the effects that stress produces in the body. Prosocial behavior also allows the individual performing the action to take his or her mind off the overwhelming circumstance and thus, stop the effects from taking a toll on the body. This paper will review the literature in order to determine if prosocial behavior would be a better coping mechanism in reducing stress, specifically in college students, than other coping mechanisms, such as exercise or temporal distancing. The paper will also try to determine if prosocial behavior can be effective in preventing long-term stress or if it is only helpful in reducing stress after it has occurred

Vapaaehtoinen alkoholin juominen : yhteys kortikosteroideihin ja testosteronitason nousuun

Alcohol dependence and alcoholism are modulated by environmental factors and genetic predisposition. Rat models have been invaluable in the investigation of several aspects of alcoholism in humans. The rodents exhibit a wide range of genetically determined alcohol-drinking preferences. Selective rat breeding programs with different alcohol preference has produced stable lines of rats that reliably exhibit high and low voluntary alcohol consumption (termed here AA and ANA, respectively). Alcohol consumption is also strongly dependent on environmental conditions. Stressful events evoke an extensive multisystem and integrative physiological response, where a major component is the activation of the hypothalamic-pituitary-adrenal (HPA) axis. Testosterone has been implicated as mediator of the rewarding effect of alcohol, and the testosterone level is predictive of future alcohol consumption. The objective of the present thesis is to examine in greater detail the relations between alcohol, testosterone and neuroendocrine stress responses, and alcohol drinking. In the first study (I), the interrelations between endogenous and alcohol-mediated effects on testosterone and corticosterone levels and voluntary alcohol consumption were studied in a crossbred F2 generation of the original AA and ANA rat lines. The second study (II) was a reinvestigation of the effect of subchronic nandrolone decanoate treatment, which in an earlier study had been shown to increase alcohol consumption, and the relation of the effect on the HPA and hypothalamic-pituitary-gonadal (HPG) axes. The third study (III) examined the possible role of benzyl alcohol, present as a preservative in the nandrolone product used in the earlier study, as a confounding factor that could explain differences between the results of the earlier study and the present one. In the fourth study (IV) the interrelations between the effect of corticosterone on alcohol-mediated testosterone changes and alcohol consumption in AA, ANA, F2 and Wistar rats were examined. The results of Study I shows connections between testosterone elevation and increased alcohol drinking, as well as between testosterone reduction and decreased alcohol drinking, which is in line with the original data of the AA and ANA lines. Elevated endogenous testosterone levels and higher frequencies of alcohol-induced testosterone increases were found in high consumption groups compared to low consumption groups. In Study II, subchronic nandrolone administration led to a reduction in alcohol-mediated testosterone levels, correlating with reduced voluntary alcohol consumption in the alcohol-preferring AA rat line. On the other hand, Study III showed that benzyl alcohol increases voluntary alcohol intake at least in the low-consumption rats, which may explain earlier discrepancies among studies. The results of Study IV were consistent with the hypothesis that corticosterone is involved in the regulation of alcohol-mediated testosterone changes. In conclusion, our present results suggests that corticosterone is a balancer, which regulates both the alcohol-mediated testosterone increase followed by reinforcement and increased voluntary alcohol drinking in high-drinking rats, and the alcohol-mediated testosterone reduction followed by disinforcement and reduced alcohol intake in low-drinking rats.Ympäristö ja geneettiset tekijät vaikuttavat alkoholiriippuvuuden ja alkoholismin kehittymiseen. Eläinmallit ovat tärkeitä välineitä ihmisen alkoholismiin liittyvien tekijöiden tutkimuksessa. Jyrsijöillä on perinnöllisiä ominaisuuksia, jotka yhdessä säätelevät mieltymystä alkoholin kulutukseen. Alkoholin kulutukseltaan toisistaan eroavia rottakantoja on jalostettu valikoimalla paljon ja vähän juovia yksilöitä erilleen sukupolvesta toiseen. Näin on saatu kehitettyä alkoholimieltymykseltään vakaat linjat fysiologista tutkimusta varten (tässä tutkimuksessa AA ja ANA rottakannat). Perintötekijöiden ohella alkoholin kulutus on myös vahvasti riippuvainen ympäristötekijöistä. Stressaavat tapahtumat käynnistävät moniulotteisen fysiologisen vastejärjestelmän kehossa. Hypotalamus-aivolisäke-lisämunuaiskuoriakselin (HPA) aktivoituminen vastaa pääasiallisesti elimistön stressivasteen muodostumisesta. Tutkimukset ovat osoittaneet yhteyden testosteronin ja alkoholin kulutuksen välillä sekä testosteronin että palkitsemiseen liittyvien hermostollisten vasteiden välillä. Testosteronitaso voi olla myös ihmisen tulevaa alkoholin käyttöä ennakoiva tekijä. Tämän tutkimuksen kohteena oli tarkemmin selvittää alkoholin, testosteronin ja elimistön fysiologisen stressivasteen välisiä suhteita. Ensimmäisessä tutkimuksessa (I) selvitettiin sisäsyntyisen testosteroni- ja kortikosteronitason, alkoholiannoksen sekä vapaaehtoisen alkoholin kulutuksen aiheuttamien muutosten keskinäisiä yhteyksiä. Tutkimuksessa käytettiin alkoholin kulutukseltaan erilaisiksi jalostettujen rottakantojen F2-sukupolven yksilöitä. Toinen tutkimus (II) tehtiin aikaisempien löydösten perusteella, joissa oli havaittu nandrolon dekanoaatti-käsittelyn lisäävän alkoholin kulutusta. Tutkimuksen tavoitteena oli selvittää, miten tämä vaikutus on yhteydessä HPA- ja HPG-akseleihin. Kolmannessa kokeessa (III) selvitettiin, oliko alkoholin kulutusta lisännyt aikaisemmassa tutkimuksessa säilöntäaineena käytetty bentsyylialkoholi, mikä selittäisi ristiriitaiset tulokset nykyiseen tutkimukseen verrattuna. Neljännen tutkimuksen (IV) tavoitteena oli selvittää tarkemmin kortikosteronin ja alkoholin aiheuttaman testosteronitason muutosten välisiä yhteyksiä AA, ANA, F2 ja Wistar rottakannoilla. Tutkimuksen I tulosten perusteella paljon ja vähän alkoholia kuluttavat rotat eroavat toisistaan testosteronin perustasojen suhteen kuten alkuperäiset AA ja ANA rottakannat. Paljon juovilla rotilla havaittiin korkeammat testosteronitasot ja enemmän alkoholin aiheuttamia testosteroninousuja kuin vähän alkoholia kuluttavilla rotilla. Tutkimuksen II tulosten perusteella havaittiin, että nandrolonikäsittely lievensi alkoholin aiheuttamaa testosteronitason nousujen määrää AA-rotilla ja vähensi alkoholin kulutusta kontrollieläimiin verrattuna. Tutkimus III osoitti, että bentsyylialkoholilla on alkoholin kulutusta lisäävä vaikutus ensisijaisesti vähän juovilla Wistar-rotilla. Tämä selittää ristiriitaa aikaisemman tutkimuksen ja nykyisen tutkimuksen II välillä. Bentsyylialkoholin vaikutusta stressivasteeseen ja testosteronitasojen nousuun ei kuitenkaan havaittu. Tutkimuksessa IV havaittiin kortikosteronin perustason olevan yhteydessä alkoholin aiheuttamaan testosteronitason muutokseen. Tutkimuksen tulosten perusteella voidaan esittää, että kortikosteroni on yhteydessä sekä alkoholin aiheuttamaan testosteronitason kohoamiseen, mikä voi lisätä alkoholin palkitsevaa vaikutusta paljon kuluttavalla rottakannalla että testosteronitason alenemiseen, mikä voi vähentää alkoholin palkitsevaa vaikutusta vähän kuluttavalla rottakannalla

Role of BDNF in the Ability of Exercise to Attenuate Dependence-Related Escalated Alcohol Drinking in C57BL/6J Mice

Alcohol use disorder (AUD) continues to be a burden to society. Currently, few efficacious treatments exist. In addition to behavioral therapy and support groups (e.g. Alcoholics Anonymous), there are only three FDA approved pharmacotherapies. The lack of treatment options for alcohol addiction denotes the need to discover and develop new strategies and pharmacological targets to improve abstinence, prevent relapse, and inhibit the development of alcohol addiction. Chronic alcohol exposure reduces brain-derived neurotrophic factor (BDNF) in the medial prefrontal cortex (mPFC). Reductions of BDNF in the mPFC drive alcohol-dependent drinking in mice and conversely, elevating BDNF in this region blocks alcohol dependence-related drinking. Therefore, enhancing TrkB (BDNF primary receptor) activity in the mPFC, by pharmacological activation or increased expression of BDNF via exercise, may provide a new treatment strategy for AUD. To engender alcohol dependence mice are exposed to repeated cycles of chronic intermittent ethanol (CIE) vapor, producing escalated alcohol drinking compared to Baseline and control (Air) mice. Additionally, deficits in Bdnf mRNA and protein are seen in the mPFC after CIE exposure. Exercise (wheel running) noninvasively induces BDNF expression in the dentate gyrus (DG) of rodents and in the blood of humans. This information led to the question of whether exercise could increase BDNF in the mPFC, reduce alcohol dependence-related drinking, and if this effect would occur through a BDNF-TrkB mediated mechanism. Studies tested the hypothesis that: Daily, limited (2-hr) voluntary wheel running would increase BDNF expression in the brain and through BDNF-TrkB signaling, attenuate CIE-induced escalated alcohol drinking. Following the Introduction, Chapter 2 demonstrates mice given limited access to a running wheel every day for several weeks, show increased Bdnf mRNA (qRT-PCR) and BDNF protein (ELISA) expression in the mPFC and DG. Building on these findings, Chapter 3 shows exercise attenuates CIE induced escalated alcohol drinking and mitigates reductions of BDNF mRNA in the mPFC caused by chronic alcohol exposure. Finally, in Chapter 4, using pharmacological inhibition of TrkB receptors, the ability of exercise to attenuate escalated alcohol intake is prevented. Taken together this study demonstrates exercise attenuates escalated alcohol intake in a model of dependence via BDNF-TrkB mediated signaling

Neurobiology of Physical Exercise: Perspectives on Psychophysiological Effects and Opioidergic Neurotransmission

Abstract: Regular physical exercise promotes health and prevents and treats multiple chronic diseases. Despite the well-acknowledged health benefits, many people remain physically inactive. Affective responses induced by exercise are believed to influence future exercise behaviour. Previous studies suggest that pleasurable sensations experienced in response to exercise are regulated by the endogenous opioid system. The opioid system is also involved in the reward processing, and may modulate food reward responses after exercise, possibly contributing to subsequent caloric intake and weight loss outcomes. In this thesis, affective responses to high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) were investigated over a two-week training intervention in untrained healthy subjects and subjects with type 2 diabetes or prediabetes. Positron emission tomography (PET) was used to explore endogenous opioid release after HIIT and MICT in young healthy subjects. The interaction between exercise-induced opioid activation and changes in food reward processing were assessed using functional magnetic resonance imaging (fMRI). HIIT generated a more negative overall affective experience in comparison with MICT; however, this lessened over the training period. Thus, HIIT appears as a tolerable exercise method for sedentary adults with and without diabetes. Furthermore, HIIT induced opioid release in key brain regions implicated in emotion and pain processing and the opioid release correlated with measures of negative emotionality. In contrast, MICT did not result in significant opioid release, although increased opioid activation correlated with increased euphoria after MICT as well as with increased neural responses to palatable foods. These results indicate that the intensity of the exercise regulates endogenous opioid release and concomitant changes in affect and reward processing. Taken together, these findings may have practical implications in developing more tolerable and likeable exercise programs to enhance physical activity participation in different population groups, as well as in optimising the efficient use of exercise in health care, for example in weight loss interventions and in the treatment of various affective disorders.Tiivistelmä: Säännöllinen liikunta ylläpitää terveyttä sekä ennaltaehkäisee ja hoitaa lukuisia sairauksia. Terveyshyödyistä huolimatta moni jää kuitenkin sohvaperunaksi. Liikunnan harrastaminen riippuu osin siitä, miltä liikunta tuntuu. Aikaisempien tutkimusten perusteella aivojen opioidijärjestelmän ajatellaan olevan liikunnasta saatavan mielihyvän taustalla. Opioidijärjestelmä säätelee myös ruuan ja syömisen aiheuttamaa mielihyvää, ja se voi siten muovata liikunnan aikaansaamia muutoksia ruuan palkitsevuudessa vaikuttaen näin syömiskäyttäytymiseen ja painonhallintaan. Tässä väitöskirjatyössä tutkittiin, miltä kovatehoinen intervalliharjoittelu (highintensity interval training, HIIT) ja keskitehoinen kestävyysharjoittelu (moderate- intensity continuous training) tuntuvat kahden viikon liikuntajakson aikana liikunnallisesti passiivisilla terveillä koehenkilöillä, sekä tyypin 2 diabeetikoilla ja esidiabeetikoilla. Lisäksi positroniemissiotomografia (PET) -kuvantamisella selvitettiin aivojen opioidijärjestelmän toimintaa HIIT ja MICT harjoitusten jälkeen terveillä nuorilla miehillä. Toiminnallisen magneettikuvantamisen (fMRI) avulla tutkittiin liikunnan vaikutuksia herkullisten ruokakuvien aikaansaamiin hermostollisiin vasteisiin aivoissa. Lyhytkestoinen HIIT aiheutti huomattavasti negatiivisemman tunnekokemuksen kuin pitkäkestoinen MICT, mikä kuitenkin helpottui jo kahden viikon harjoittelujakson aikana niin terveillä kuin tyypin 2 diabeetikoilla ja esidiabeetikoilla. Näin ollen rankka HIIT voi soveltua liikuntavaihtoehdoksi myös aikaisemmin liikuntaa harrastamattomille. Lisäksi havaittiin, että liikunnan intensiteetti säätelee opioidijärjestelmän toimintaa. HIIT vapautti endogeenisiä opioideja tunteiden ja kivun säätelyyn liittyvillä aivoalueilla. Opioidien vapautuminen oli yhteydessä negatiivisiin tuntemuksiin. Vastaavaa opioidien vapautumista ei havaittu MICT:n jälkeen, joskin suurempi opioidiaktivaatio oli yhteydessä lisääntyneeseen euforisuuden tuntemukseen ja suurempiin hermostollisiin vasteisiin herkullisille ruokakuville pitkäkestoisen liikunnan jälkeen. Tutkimuksista saatuja tuloksia voidaan hyödyntää kehitettäessä uudenlaisia lähestymistapoja paitsi ihmisten liikunnalliseen aktivoimiseen, myös liikunnan tehokkaampaan hyödyntämiseen painonpudotuksessa ja esimerkiksi masennuksen ja riippuvuuksien hoidossa

A translational approach of mouse and human studies to integrate chronobiology into therapies for psychiatric disorders

Background Circadian rhythms are endogenous manifestations of the external 24-hour light-dark cycle that allow the organism to adapt and to anticipate daily temporal changes in the environment. These ~24-hour rhythms, also called circadian clocks, are driven by clock genes in almost each cell throughout our body and are set to 24 hours each day by the external light and dark cycle. Because circadian clocks regulate virtually all of our physiology and behavior, organisms may be susceptible to various types of disorders when circadian rhythms are disrupted. Thus, there is, for example, a bidirectional relationship between the disturbance of circadian clocks and the development of psychiatric disorders, such as anxiety disorders, and alcohol use disorder (AUD), whereby alcohol consumption can influence the circadian system, but conversely, disturbed circadian rhythms are a risk factor for addiction. Results We show that Cryptochrome 1 and 2 (Cry1/2-/-) double knockout mice, which do not express endogenous circadian rhythms, exhibit a pronounced anxiety-like phenotype and are more sensitive to stressful situations. These behavioral effects are confirmed by increased neuronal activity (c-Fos) in the basolateral amygdala. Furthermore, we show that the Cry1/2-/- mice exhibit distinct traits that predispose humans to an increased risk of problematic alcohol consumption. Cry1/2-/- mice show lower alcohol consumption behavior (liking) concomitant with higher motivation to acquire the substance (wanting), a finding that is consistent with the incentive sensitization theory of addiction. These phenotypes are also supported by molecular analyses: In the absence of the Cry genes, the stress hormone corticosterone is continuously elevated, and the level of the orexin precursor prepro-orexin is persistently low, which together represent explanatory factors for an overall altered alcohol preference. In terms of gene-environment interaction, the phenotype of altered alcohol drinking behavior of Cry1/2-/- mice, was enhanced by additional environmental circadian perturbations (shift work model). Outlook Our results underline the importance of stable endogenous and environmental circadian rhythms as well as their interaction for mental health. From our findings, we assume that patients suffering from anxiety disorders, AUD, or both, regardless of whether underlying circadian rhythm disturbances are genetically or environmentally induced, may benefit from chronotherapies. This is why, based on our results, we developed a new adjunctive chronotherapeutic treatment for AUD patients

Theories of anterior cingulate cortex function : opportunity cost

The target article highlights the role of the anterior cingulate cortex (ACC) in conflict monitoring, but ACC function may be better understood in terms of the hierarchical organization of behavior. This proposal suggests that the ACC selects extended goal-directed actions according to their learned costs and benefits and executes those behaviors subject to depleting resources

The Neural Mechanisms of Meditative Practices: Novel Approaches for Healthy Aging

ObjectivesMeditation has been shown to have physical, cognitive, and psychological health benefits that can be used to promote healthy aging. However, the common and specific mechanisms of response remain elusive due to the diverse nature of mind-body practices.MethodsIn this review, we aim to compare the neural circuits implicated in focused-attention meditative practices that focus on present-moment awareness to those involved in active-type meditative practices (e.g., yoga) that combine movement, including chanting, with breath practices and meditation.Recent findingsRecent meta-analyses and individual studies demonstrated common brain effects for attention-based meditative practices and active-based meditations in areas involved in reward processing and learning, attention and memory, awareness and sensory integration, and self-referential processing and emotional control, while deactivation was seen in the amygdala, an area implicated in emotion processing. Unique effects for mindfulness practices were found in brain regions involved in body awareness, attention, and the integration of emotion and sensory processing. Effects specific to active-based meditations appeared in brain areas involved in self-control, social cognition, language, speech, tactile stimulation, sensorimotor integration, and motor function.SummaryThis review suggests that mind-body practices can target different brain systems that are involved in the regulation of attention, emotional control, mood, and executive cognition that can be used to treat or prevent mood and cognitive disorders of aging, such as depression and caregiver stress, or serve as "brain fitness" exercise. Benefits may include improving brain functional connectivity in brain systems that generally degenerate with Alzheimer's disease, Parkinson's disease, and other aging-related diseases

Non-nociceptive roles of opioids in the CNS: opioids' effects on neurogenesis, learning, memory and affect.

Mortality due to opioid use has grown to the point where, for the first time in history, opioid-related deaths exceed those caused by car accidents in many states in the United States. Changes in the prescribing of opioids for pain and the illicit use of fentanyl (and derivatives) have contributed to the current epidemic. Less known is the impact of opioids on hippocampal neurogenesis, the functional manipulation of which may improve the deleterious effects of opioid use. We provide new insights into how the dysregulation of neurogenesis by opioids can modify learning and affect, mood and emotions, processes that have been well accepted to motivate addictive behaviours

How Does the Body Affect the Mind? Role of Cardiorespiratory Coherence in the Spectrum of Emotions

The brain is considered to be the primary generator and regulator of emotions; however, afferent signals originating throughout the body are detected by the autonomic nervous system (ANS) and brainstem, and, in turn, can modulate emotional processes. During stress and negative emotional states, levels of cardiorespiratory coherence (CRC) decrease, and a shift occurs toward sympathetic dominance. In contrast, CRC levels increase during more positive emotional states, and a shift occurs toward parasympathetic dominance. Te dynamic changes in CRC that accompany different emotions can provide insights into how the activity of the limbic system and afferent feedback manifest as emotions. The authors propose that the brainstem and CRC are involved in important feedback mechanisms that modulate emotions and higher cortical areas. That mechanism may be one of many mechanisms that underlie the physiological and neurological changes that are experienced during pranayama and meditation and may support the use of those techniques to treat various mood disorders and reduce stress