Molecular genetics of dopa decarboxylase and biogenic amines in <i>Drosophila</i>

Hirsh, Jay

doi:10.1002/dvg.1020100312

Cited by 20 publications

(6 citation statements)

References 31 publications

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“…Little is known about the mechanisms underlying RI. Vertebrate studies suggest the involvement of serotonin [38,39]; it is unclear whether serotonin plays a role in insect learning ( [40][41][42][43]; but see [44]). Interestingly, PKG is thought to modulate serotonin (5-hydroxytryptamine; 5-HT) transporter activity [43].…”

Section: Discussionmentioning

confidence: 99%

A natural genetic polymorphism affects retroactive interference inDrosophila melanogaster

2010

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As environments change, animals update their internal representations of the external world. New information about the environment is learned and retained whereas outdated information is disregarded or forgotten. Retroactive interference (RI) occurs when the retrieval of previously learned information is less available owing to the acquisition of recently acquired information. Even though RI is thought to be a major cause of forgetting, its functional significance is still under debate. We find that natural allelic variants of the Drosophila melanogaster foraging gene known to affect rover and sitter behaviour differ in RI. More specifically, rovers who were previously shown to experience greater environmental heterogeneity while foraging display RI whereas sitters do not. Rover responses are biased towards more recent learning events. These results provide an ecological context to investigate the function of forgetting via RI and a suitable genetic model organism to address the evolutionary relevance of cognitive tasks.

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Section: Discussionmentioning

confidence: 99%

A natural genetic polymorphism affects retroactive interference inDrosophila melanogaster

2010

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“…Based on their positions, cellular morphologies, and immunostaining with the above markers, the cells within the c929 pattern represent more than 26 distinct classes of peptidergic neurons and endocrine cells. No c929-positive neurons were stained with an antiserum to dopa decarboxylase (n=8), an enzyme required for synthesis of the biogenic amines, serotonin and dopamine (Hirsh, 1989).…”

Section: C929 Is Broadly Expressed In Peptidergic Cellsmentioning

confidence: 99%

The bHLH protein Dimmed controls neuroendocrine cell differentiation inDrosophila

et al. 2003

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Neuroendocrine cells are specialized to produce, maintain and release large stores of secretory peptides. We show that the Drosophila dimmed/Mist1 bHLH gene confers such a pro-secretory phenotype on neuroendocrine cells. dimmed is expressed selectively in central and peripheral neuroendocrine cells. In dimmed mutants, these cells survive, and adopt normal cell fates and morphology. However, they display greatly diminished levels of secretory peptide mRNAs, and of diverse peptides and proteins destined for regulated secretion. Secretory peptide levels are lowered even in the presence of artificially high secretory peptide mRNA levels. In addition, overexpression of dimmed in a wild-type background produces a complimentary phenotype: an increase in secretory peptide levels by neuroendocrine cells, and an increase in the number of cells displaying a neuroendocrine phenotype. We propose that dimmed encodes an integral component of a novel mechanism by which diverse neuroendocrine lineages differentiate and maintain the pro-secretory state. 1772 dimmed (dimm), with an expression pattern that corresponds precisely to the neuronal and endocrine cells that accumulate large amounts of secretory peptides. We present both loss-offunction and gain-of-function analyses to argue that dimm confers a pro-secretory phenotype within these diverse cells, and that its actions appear confined to that aspect of cellular differentiation. Thus, we propose a novel and general mechanism, of which dimm is an essential component, for the amplification of the regulated secretory pathway by dedicated secretory cells. MATERIALS AND METHODS StrainsFlies were cultured at 22-25°C on a standard cornmeal-yeast-agar medium. The molecular and genetic characterization of c929, R6 and Rev8 has been described previously (Hewes et al., 2000). Rev4 and Rev18 are X-ray revertants of P{PZ}l (2)k05106 S2a ) were obtained by transposase-mediated excision, and each line was characterized by PCR with primers flanking the original insertion site. Except as noted, all other strains are described elsewhere (Lindsley and Zimm, 1992;FlyBase, 1999) and were obtained from the Bloomington stock center, the BDGP Gene Disruption Project and other sources. Scoring of dimm larvaeEggs were collected on apple juice-agar plates supplemented with yeast paste. Larvae were collected from the plates, and heterozygotes (y* w* and balanced over CyO-y + ) were distinguished by mouthpart color. After scoring, size-matched pairs of y -and y + larvae were dissected and stained in parallel.

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“…Thus, support grows for a general function of the dopaminergic system in negatively reinforced memory. Whether serotonin has a role in insect learning is less clear (10), and in Drosophila it is controversial (11)(12)(13). Here, we investigated the influence of serotonin and dopamine on reinforcement of place learning in Drosophila.…”

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confidence: 99%

Serotonin is necessary for place memory in Drosophila

Sitaraman¹,

Zars²,

LaFerriere³

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

259

298

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Biogenic amines, such as serotonin and dopamine, can be important in reinforcing associative learning. This function is evident as changes in memory performance with manipulation of either of these signals. In the insects, evidence begins to argue for a common role of dopamine in negatively reinforced memory. In contrast, the role of the serotonergic system in reinforcing insect associative learning is either unclear or controversial. We investigated the role of both of these signals in operant place learning in Drosophila. By genetically altering serotonin and dopamine levels, manipulating the neurons that make serotonin and dopamine, and pharmacological treatments we provide clear evidence that serotonin, but not dopamine, is necessary for place memory. Thus, serotonin can be critical for memory formation in an insect, and dopamine is not a universal negatively reinforcing signal.biogenic amines ͉ dopamine ͉ learning ͉ white-ABC transporter ͉ reinforcement T he neural systems containing biogenic amines, such as dopamine and serotonin, may mediate reinforcement information to influence memory performance. In the monkey for example, activity in the dopaminergic system is modulated based on expected reward (1), and the phasic output of these neurons may regulate memory performance (1, 2). In some invertebrates the biogenic amines have also been shown to be critical for conditioning (3)(4)(5). Within the insects, however, dopamine is the only biogenic amine clearly implicated in negatively reinforced associative memory (6-8). Indeed, and interestingly, dopaminergic system activation can be a sufficient reinforcing signal for olfactory conditioning in Drosophila larvae (9). Thus, support grows for a general function of the dopaminergic system in negatively reinforced memory. Whether serotonin has a role in insect learning is less clear (10), and in Drosophila it is controversial (11-13). Here, we investigated the influence of serotonin and dopamine on reinforcement of place learning in Drosophila.The ''heat box'' can be used to rapidly condition place memories in Drosophila (14,15). In this paradigm, single flies are allowed to wander in a chamber that is lined top and bottom with Peltier heating elements ( Fig. 1) (16, 17). A series of light sensors on one side of the chamber tracks the behavior of a fly, and when the animal moves to a predetermined half, the whole chamber heats to a nonpreferred (aversive) temperature. With experience, normal flies avoid the chamber-half associated with rising temperatures (15,16,18). A test performed after conditioning, when the danger of rising temperature is removed, is used to measure place memory. Importantly, one can dissociate acquisition from reinforcement processing defects by the performance of mutant flies after short and long training sessions (19). Flies that are mutant for a type-1 adenylyl cyclase (i.e., rutabaga) show poor memory performance after short periods of conditioning but normal memory after longer training, emphasizing the memory acquisition function for...

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Molecular genetics of dopa decarboxylase and biogenic amines in Drosophila

Cited by 20 publications

References 31 publications

A natural genetic polymorphism affects retroactive interference inDrosophila melanogaster

A natural genetic polymorphism affects retroactive interference inDrosophila melanogaster

The bHLH protein Dimmed controls neuroendocrine cell differentiation inDrosophila

Serotonin is necessary for place memory in Drosophila

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