Abstract
What is particularly worth remembering about a traumatic experience is what brought it about, and what made it cease. For example, fruit flies avoid an odor which during training had preceded electric shock punishment; on the other hand, if the odor had followed shock during training, it is later on approached as a signal for the relieving end of shock. We provide a neurogenetic analysis of such relief learning. Blocking, using UAS-shibirets1, the output from a particular set of dopaminergic neurons defined by the TH-Gal4 driver partially impaired punishment learning, but left relief learning intact. Thus, with respect to these particular neurons, relief learning differs from punishment learning. Targeting another set of dopaminergic/serotonergic neurons defined by the DDC-Gal4 driver on the other hand affected neither punishment nor relief learning. As for the octopaminergic system, the tbhM18 mutation, compromising octopamine biosynthesis, partially impaired sugar-reward learning, but not relief learning. Thus, with respect to this particular mutation, relief learning, and reward learning are dissociated. Finally, blocking output from the set of octopaminergic/tyraminergic neurons defined by the TDC2-Gal4 driver affected neither reward, nor relief learning. We conclude that regarding the used genetic tools, relief learning is neurogenetically dissociated from both punishment and reward learning. This may be a message relevant also for analyses of relief learning in other experimental systems including man.
Highlights
Having no idea as to what will happen is bewildering, but can be dangerous
Blocking, using UAS-shibirets1, the output from a particular set of dopaminergic neurons defined by theTH-Gal4 driver partially impaired punishment learning, but left relief learning intact.with respect to these particular neurons, relief learning differs from punishment learning.Targeting another set of dopaminergic/serotonergic neurons defined by the DDC-Gal4 driver on the other hand affected neither punishment nor relief learning
All dopaminergic neuron clusters in the fly brain are targeted by the TH-Gal4 driver; some clusters are covered only partially, e.g., 80–90% of the anterior medial “PAM cluster” neurons are left out (Friggi-Grelin et al, 2003; Sitaraman et al, 2008; Claridge-Chang et al, 2009; Mao and Davis, 2009)
Summary
Having no idea as to what will happen is bewildering, but can be dangerous. Such predictive learning qualitatively depends on the relative timing of events: a stimulus that occurred once a traumatic event had subsided later on supports opposite behavioral tendencies, such as approach, as it signals what may be called relief (Solomon and Corbit, 1974; Wagner, 1981) or safety (Sutton and Barto, 1990; Chang et al, 2003) Such opposing memories about the beginning and end of traumatic experiences are common to distant phyla (e.g., dog: Moskovitch and LoLordo, 1968, rabbit: Plotkin and Oakley, 1975, rat: Maier et al, 1976, snail: Britton and Farley, 1999, adult fruit fly: Tanimoto et al, 2004; Yarali et al, 2008, 2009; Murakami et al, 2010, larval fruit fly: Khurana et al, 2009), including man (Andreatta et al, 2010). To fully appreciate the behavioral consequences of affective experiences, it is necessary to study the mnemonic effects of their beginning and their end
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
