Cell type-specific driver lines targeting the central complex and their use to investigate neuropeptide expression and sleep regulation.

The central complex (CX) plays a key role in many higher-order functions of the insect brain including navigation and activity regulation. Genetic tools for manipulating individual cell types, and knowledge of what neurotransmitters and neuromodulators they express, will be required to gain mechanistic understanding of how these functions are implemented. We generated and characterized split-GAL4 driver lines that express in individual or small subsets of about half of CX cell types.

Analysis of Sleep and Circadian Rhythms from Activity-Monitoring Data Using SCAMP.

Sleep is a fundamental feature of life for virtually all multicellular animals, but many questions remain about how sleep is regulated and what biological functions it plays. Substantial headway has been made in the study of both circadian rhythms and sleep in the fruit fly , much of it through studies of individual fly activity using beam break counts from activity monitors (DAMs). The number of laboratories worldwide studying sleep in has grown from only a few 20 years ago to hundreds today.

Neural Stimulation during Activity Monitor (DAM)-Based Studies of Sleep and Circadian Rhythms in .

Sleep is a fundamental feature of life for virtually all multicellular animals, but many questions remain about how sleep is regulated by circadian rhythms, homeostatic sleep drive that builds up with wakefulness, and modifying factors such as hunger or social interactions, as well as about the biological functions of sleep. Substantial headway has been made in the study of both circadian rhythms and sleep in the fruit fly , much of it through studies of individual fly activity using activity monitors (DAMs). Here, we describe approaches for the activation of specific neurons of interest using optogenetics (involving genetic modifications that allow for light-based neuronal activation) and thermogenetics (involving genetic modifications that allow for temperature-based neuronal activation) so that researchers can evaluate the roles of those neurons in controlling rest and activity behavior.

Activity Monitoring for Analysis of Sleep in .

Sleep is important for survival, and the need for sleep is conserved across species. In the past two decades, the fruit fly has emerged as a promising system in which to study the genetic, neural, and physiological bases of sleep. Through significant advances in our understanding of the regulation of sleep in flies, the field is poised to address several open questions about sleep, such as how the need for sleep is encoded, how molecular regulators of sleep are situated within brain networks, and what the functions of sleep are.

Sleep correlates with behavioral decision making critical for reproductive output in Drosophila melanogaster.

Balance between sleep, wakefulness and arousal is important for survival of organisms and species as a whole. While, the benefits of sleep both in terms of quantity and quality is widely recognized across species, sleep has a cost for organismal survival and reproduction. Here we focus on how sleep duration, sleep depth and sleep pressure affect the ability of animals to engage in courtship and egg-laying behaviors critical for reproductive success.

Utilizing comparative models in biomedical research.

This review serves as an introduction to a Special Issue of Comparative Biochemistry and Physiology, focused on using non-human models to study biomedical physiology. The concept of a model differs across disciplines. For example, several models are used primarily to gain an understanding of specific human pathologies and disease states, whereas other models may be focused on gaining insight into developmental or evolutionary mechanisms.

WITHDRAWN: Utilizing comparative models in biomedical research.

The Publisher regrets that this article is an accidental duplication of an article that has already been published in Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology, Volume 255, 2021, 110593, https://doi.org/10.1016/j.

A biographical sketch of Troy D. Zars (1967-2018).

Troy D. Zars (1967-2018) was an American biologist. He studied the relationships between genes, neuronal circuits and behavior in the fruit fly .

Finding a place and leaving a mark in memory formation.

Preference for spatial locations to maximize favorable outcomes and minimize aversive experiences helps animals survive and adapt to the changing environment. Both visual and non-visual cues play a critical role in spatial navigation and memory of a place supports and guides these strategies. Here we present the neural, genetic and behavioral processes involved in place memory formation using with a focus on non-visual cue based spatial memories.

Measurement of Sleep and Arousal in .

Sleep is a conserved neurobehavioral state observed in animals with sufficiently complex nervous systems and is critical for survival. While the exact function of sleep remains unknown, the lack of sleep can have a range of physiological and behavioral effects. Studies in invertebrates and vertebrates have identified conserved neural mechanisms and cellular pathways in control of sleep, wakefulness and arousal.

Aversive and Appetitive Learning in Larvae: A Simple and Powerful Suite of Laboratory Modules for Classroom or Open-ended Research Projects.

A key element of laboratory courses introducing students to neuroscience includes behavioral exercises. Associative learning experiments often conducted in research laboratories are difficult to perform and time consuming. Commonly, these experiments cannot be performed without extensive instrumentation or animal care facilities.

Discrete Serotonin Systems Mediate Memory Enhancement and Escape Latencies after Unpredicted Aversive Experience in Place Memory.

Feedback mechanisms in operant learning are critical for animals to increase reward or reduce punishment. However, not all conditions have a behavior that can readily resolve an event. Animals must then try out different behaviors to better their situation through outcome learning.

Genetic and neuronal mechanisms governing the sex-specific interaction between sleep and sexual behaviors in Drosophila.

Animals execute one particular behavior among many others in a context-dependent manner, yet the mechanisms underlying such behavioral choice remain poorly understood. Here we studied how two fundamental behaviors, sex and sleep, interact at genetic and neuronal levels in Drosophila. We show that an increased need for sleep inhibits male sexual behavior by decreasing the activity of the male-specific P1 neurons that coexpress the sex determination genes fru and dsx, but does not affect female sexual behavior.

A Peptidergic Circuit Links the Circadian Clock to Locomotor Activity.

The mechanisms by which clock neurons in the Drosophila brain confer an ∼24-hr rhythm onto locomotor activity are unclear, but involve the neuropeptide diuretic hormone 44 (DH44), an ortholog of corticotropin-releasing factor. Here we identified DH44 receptor 1 as the relevant receptor for rest:activity rhythms and mapped its site of action to hugin-expressing neurons in the subesophageal zone (SEZ). We traced a circuit that extends from Dh44-expressing neurons in the pars intercerebralis (PI) through hugin+ SEZ neurons to the ventral nerve cord.

Corrigendum: Control of Sleep by Dopaminergic Inputs to the Drosophila Mushroom Body.

[This corrects the article on p. 73 in vol. 9, PMID: 26617493.

Control of Sleep by Dopaminergic Inputs to the Drosophila Mushroom Body.

The Drosophila mushroom body (MB) is an associative learning network that is important for the control of sleep. We have recently identified particular intrinsic MB Kenyon cell (KC) classes that regulate sleep through synaptic activation of particular MB output neurons (MBONs) whose axons convey sleep control signals out of the MB to downstream target regions. Specifically, we found that sleep-promoting KCs increase sleep by preferentially activating cholinergic sleep-promoting MBONs, while wake-promoting KCs decrease sleep by preferentially activating glutamatergic wake-promoting MBONs.

Propagation of Homeostatic Sleep Signals by Segregated Synaptic Microcircuits of the Drosophila Mushroom Body.

The Drosophila mushroom body (MB) is a key associative memory center that has also been implicated in the control of sleep. However, the identity of MB neurons underlying homeostatic sleep regulation, as well as the types of sleep signals generated by specific classes of MB neurons, has remained poorly understood. We recently identified two MB output neuron (MBON) classes whose axons convey sleep control signals from the MB to converge in the same downstream target region: a cholinergic sleep-promoting MBON class and a glutamatergic wake-promoting MBON class.

Mushroom body output neurons encode valence and guide memory-based action selection in Drosophila.

Animals discriminate stimuli, learn their predictive value and use this knowledge to modify their behavior. In Drosophila, the mushroom body (MB) plays a key role in these processes. Sensory stimuli are sparsely represented by ∼2000 Kenyon cells, which converge onto 34 output neurons (MBONs) of 21 types.

Serotonin is critical for rewarded olfactory short-term memory in Drosophila.

The biogenic amines dopamine, octopamine, and serotonin are critical in establishing normal memories. A common view for the amines in insect memory performance has emerged in which dopamine and octopamine are largely responsible for aversive and appetitive memories. Examination of the function of serotonin begins to challenge the notion of one amine type per memory because altering serotonin function also reduces aversive olfactory memory and place memory levels.

Lack of prediction for high-temperature exposures enhances Drosophila place learning.

Animals receive rewards and punishments in different patterns. Sometimes stimuli or behaviors can become predictors of future good or bad events. Through learning, experienced animals can then avoid new but similar bad situations, or actively seek those conditions that give rise to good results.

Place memory formation in Drosophila is independent of proper octopamine signaling.

The biogenic amines play a critical role in establishing memories. In the insects, octopamine, dopamine, and serotonin have key functions in memory formation. For Drosophila, octopamine is necessary and sufficient for appetitive olfactory memory formation.

Genetic dissociation of ethanol sensitivity and memory formation in Drosophila melanogaster.

The ad hoc genetic correlation between ethanol sensitivity and learning mechanisms in Drosophila could overemphasize a common process supporting both behaviors. To challenge directly the hypothesis that these mechanisms are singular, we examined the learning phenotypes of 10 new strains. Five of these have increased ethanol sensitivity, and the other 5 do not.

Serotonin is necessary for place memory in Drosophila.

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.