Roles of octopaminergic and dopaminergic neurons in appetitive and aversive memory recall in an insect

<p>Abstract</p> <p>Background</p> <p>In insect classical conditioning, octopamine (the invertebrate counterpart of noradrenaline) or dopamine has been suggested to mediate reinforcing properties of appetitive or aversive unconditioned stimulus, respectively. However, the roles of octopaminergic and dopaminergic neurons in memory recall have remained unclear.</p> <p>Results</p> <p>We studied the roles of octopaminergic and dopaminergic neurons in appetitive and aversive memory recall in olfactory and visual conditioning in crickets. We found that pharmacological blockade of octopamine and dopamine receptors impaired aversive memory recall and appetitive memory recall, respectively, thereby suggesting that activation of octopaminergic and dopaminergic neurons and the resulting release of octopamine and dopamine are needed for appetitive and aversive memory recall, respectively. On the basis of this finding, we propose a new model in which it is assumed that two types of synaptic connections are formed by conditioning and are activated during memory recall, one type being connections from neurons representing conditioned stimulus to neurons inducing conditioned response and the other being connections from neurons representing conditioned stimulus to octopaminergic or dopaminergic neurons representing appetitive or aversive unconditioned stimulus, respectively. The former is called 'stimulus-response connection' and the latter is called 'stimulus-stimulus connection' by theorists studying classical conditioning in higher vertebrates. Our model predicts that pharmacological blockade of octopamine or dopamine receptors during the first stage of second-order conditioning does not impair second-order conditioning, because it impairs the formation of the stimulus-response connection but not the stimulus-stimulus connection. The results of our study with a cross-modal second-order conditioning were in full accordance with this prediction.</p> <p>Conclusion</p> <p>We suggest that insect classical conditioning involves the formation of two kinds of memory traces, which match to stimulus-stimulus connection and stimulus-response connection. This is the first study to suggest that classical conditioning in insects involves, as does classical conditioning in higher vertebrates, the formation of stimulus-stimulus connection and its activation for memory recall, which are often called cognitive processes.</p

Neuroarchitecture of Aminergic Systems in the Larval Ventral Ganglion of Drosophila melanogaster

Biogenic amines are important signaling molecules in the central nervous system of both vertebrates and invertebrates. In the fruit fly Drosophila melanogaster, biogenic amines take part in the regulation of various vital physiological processes such as feeding, learning/memory, locomotion, sexual behavior, and sleep/arousal. Consequently, several morphological studies have analyzed the distribution of aminergic neurons in the CNS. Previous descriptions, however, did not determine the exact spatial location of aminergic neurite arborizations within the neuropil. The release sites and pre-/postsynaptic compartments of aminergic neurons also remained largely unidentified. We here used gal4-driven marker gene expression and immunocytochemistry to map presumed serotonergic (5-HT), dopaminergic, and tyraminergic/octopaminergic neurons in the thoracic and abdominal neuromeres of the Drosophila larval ventral ganglion relying on Fasciclin2-immunoreactive tracts as three-dimensional landmarks. With tyrosine hydroxylase- (TH) or tyrosine decarboxylase 2 (TDC2)-specific gal4-drivers, we also analyzed the distribution of ectopically expressed neuronal compartment markers in presumptive dopaminergic TH and tyraminergic/octopaminergic TDC2 neurons, respectively. Our results suggest that thoracic and abdominal 5-HT and TH neurons are exclusively interneurons whereas most TDC2 neurons are efferent. 5-HT and TH neurons are ideally positioned to integrate sensory information and to modulate neuronal transmission within the ventral ganglion, while most TDC2 neurons appear to act peripherally. In contrast to 5-HT neurons, TH and TDC2 neurons each comprise morphologically different neuron subsets with separated in- and output compartments in specific neuropil regions. The three-dimensional mapping of aminergic neurons now facilitates the identification of neuronal network contacts and co-localized signaling molecules, as exemplified for DOPA decarboxylase-synthesizing neurons that co-express crustacean cardioactive peptide and myoinhibiting peptides

How physically active are women after breast cancer at the beginning of medical rehabilitation and what is their understanding of sports and physical activity?

Purpose: Sports and physical activity after breast cancer have been proven effective for physical and mental health outcomes. However, for the majority of the women it is a challenge to meet recommended guidelines for physical activity. Yet, it is not known to what extent women after breast cancer exercise at the beginning of medical rehabilitation and what associations they have with the terms sports and physical activity . Certain negative associations could possibly influence their behaviour. The aim of the study is to assess the extent of exercise in women after breast cancer at the beginning of medical rehabilitation quantitatively. Qualitatively, it should be discussed which associations the terms sports and physical activity evoke in this target group.Methods: In a cross-sectional study at the beginning of medical rehabilitation we collected data using the short questionnaire of physical activity (BSA-F). To investigate associations, motives and barriers regarding sports and physical activity, we conducted 21 guided interviews. The interviews were digitized and transcribed. The analysis was carried out deductively-inductively according to the structured qualitative content analysis. The target group were adult women after breast cancer with approved medical rehabilitation.Results: 3.123 women answered the questionnaire on the amount of exercising. The average duration is 98 minutes per week (95% CI: 93-103 min/w). Half of the women (n=1.564) report of less than 60 minutes per week of exercise. The qualitative results include three deductively formed categories (associations with sports and physical activity, motives for sports and physical activity, barriers to taking up or continuing sports and physical activity) and ten inductively formed categories (associations with sports, positive emotions, negative emotions, associations physical activity, no distinction/movement as a synonym, physical motives, psychosocial motives, psychological barriers, physical barriers, environmental barriers). We could not identify any lay knowledge on physical rest after being diagnosed with cancer. The majority of respondents distinguishes between sports and physical activity. The greater number of women do not care which of the terms is used. Typical characteristics such as effort, achievement, or ambition are associated with sports. Movement is often used as a synonym, which could be important for the choice of names for exercise courses. Most of the statements have positive connotations; exercising leads to balance and happiness in women. Negative emotions are mainly based on childhood experiences. Women associate physical activity with everyday activities. The motives for exercising include health, fitness, and disease management. One of the most frequently mentioned barriers is a lack of motivation.Conclusion: Every second women after breast cancer exercises less than 60 minutes per week. There is no evidence that the terms sports and physical activity have any influence on exercise behavior. The identified associations, motives, and barriers are comparable to other studies. The term exercise should find more consideration when naming sports offers for this target group.Ziel der Studie: Sportliche Aktivität (SpA) und körperliche Aktivität (KA) nach Brustkrebs haben positiven Einfluss auf physische und psychische Parameter. Für den Großteil der Betroffenen ist es jedoch eine Herausforderung, Bewegungsempfehlungen umzusetzen. Unbekannt ist, in welchem zeitlichen Umfang Frauen nach Brustkrebs zu Beginn der medizinischen Rehabilitation sportlich aktiv sind und welche Assoziationen sie zu den Begriffen SpA und KA haben. Möglicherweise beeinflussen negative Zuschreibungen (u.a. Angst) das Bewegungsverhalten. Quantitativ soll der Umfang SpA bei Frauen nach Brustkrebs zu Beginn der medizinischen Rehabilitation erhoben werden und qualitativ soll erörtert werden, welche Assoziationen die Begriffe SpA und KA bei dieser Zielgruppe hervorrufen.Methodik: Den Umfang SpA erhoben wir in einer querschnittlichen Befragung zu Beginn der medizinischen Rehabilitation in zwei Einrichtungen mit dem Kurzfragebogen (BSA-F). Um Begriffsassoziationen, Motive und Barrieren in Bezug auf SpA und KA zu erfassen, haben wir 21 leitfadengestützte Interviews geführt, digitalisiert und transkribiert. Die Auswertung erfolgte deduktiv-induktiv nach der strukturierenden qualitativen Inhaltsanalyse. Zielgruppe waren erwachsene Frauen nach Brustkrebs mit bewilligter medizinischer Rehabilitation.Ergebnisse: 3.123 Frauen haben Angaben zum zeitlichen Umfang SpA gemacht. Die durchschnittliche Dauer der Sportaktivitäten beträgt 98 Min/Wo (95% CI: 93-103 Min/Wo). Die Hälfte der Frauen (n=1.564) gibt an, sich pro Woche weniger als 60 Minuten zu bewegen. Die qualitativen Ergebnisse umfassen drei deduktiv gebildete Kategorien (Begriffsverständnis und Assoziationen zu SpA und KA, Gründe und Motive für SpA und KA, Hürden für die Aufnahme oder Weiterführung SpA und KA) und zehn induktiv gebildete Kategorien (Assoziationen SpA, positive Emotionen, negative Emotionen, Assoziationen KA, keine Unterscheidung/Bewegung als Synonym, physische Motive, psychosoziale Motive, psychologische Barrieren, physische Barrieren, Umfeld bedingte Barrieren). Ein Laienwissen zu körperlicher Schonung bei Krebserkrankungen konnten wir nicht identifizieren. Die überwiegende Anzahl der Befragten differenziert zwischen SpA und KA. Der Mehrheit der Frauen ist nicht wichtig, welcher der Begriffe verwendet wird. Mit SpA werden typische Merkmale wie Anstrengung, Leistung oder Ehrgeiz verbunden. Bewegung wird häufig als Synonym verwendet, was für die Namenswahl von Bewegungsangeboten von Bedeutung sein könnte. Der Großteil der Aussagen ist positiv konnotiert; SpA führt bei den Frauen zu Ausgeglichenheit und Glücksgefühlen. Negativ behaftete Emotionen beruhen überwiegend auf Erfahrungen in der Kindheit. KA verbinden die Frauen mit Alltagsaktivitäten. Zu den Motiven, um SpA auszuüben, zählen u.a. Gesundheit, Fitness und Krankheitsbewältigung. Eine häufig genannte Barriere ist die fehlende Motivation.Schlussfolgerung: Jede zweite Frau nach Brustkrebs ist zu Beginn einer medizinischen Rehabilitationsmaßnahme weniger als 60 Min/Wo sportlich aktiv. Es gibt keine Hinweise darauf, dass das Begriffsverständnis zu SpA und KA Einfluss auf das Bewegungsverhalten hat. Die identifizierten Assoziationen, Motive und Barrieren sind vergleichbar mit anderen Untersuchungen. Der Begriff Bewegung sollte bei der Betitelung von Sportangeboten für diese Zielgruppe berücksichtig werden