David J. Schulz

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How different are the neuronal circuits for a given behavior across individual animals? To address this question, we measured multiple cellular and synaptic parameters in individual preparations to see how they correlated with circuit function, using neurons and synapses in the pyloric circuit of the stomatogastric ganglion of the crab Cancer borealis.(More)
It is often assumed that all neurons of the same cell type have identical intrinsic properties, both within an animal and between animals. We exploited the large size and small number of unambiguously identifiable neurons in the crab stomatogastric ganglion to test this assumption at the level of channel mRNA expression and membrane currents (measured in(More)
The biogenic amine neurochemical octopamine is involved in the onset of foraging behaviour in honey bees. We tested the hypothesis that octopamine influences honey bee behavioural development by modulating responsiveness to task-related stimuli. We examined the effect of octopamine treatment on responsiveness to brood pheromone (an activator of foraging)(More)
The postdevelopmental basis of cellular identity and the unique cellular output of a particular neuron type are of particular interest in the nervous system because a detailed understanding of circuits responsible for complex processes in the brain is impeded by the often ambiguous classification of neurons in these circuits. Neurons have been classified by(More)
Brain levels of dopamine, serotonin, and octopamine were measured in relation to both age-related division of labor and inter-individual differences in task specialization independent of age in honey bee colonies. The only differences among similarly aged bees performing different tasks were significantly lower levels of dopamine in food storers than comb(More)
Central pattern generators (CPGs) are circuits that generate organized and repetitive motor patterns, such as those underlying feeding, locomotion and respiration. We summarize recent work on invertebrate CPGs which has provided new insights into how rhythmic motor patterns are produced and how they are controlled by higher-order command and modulatory(More)
Forager honey bees have higher brain levels of octopamine than do bees tending larvae in the hive. To test the hypothesis that octopamine influences honey bee division of labor we treated bees orally with octopamine or its immediate precursor tyramine and determined whether these treatments increased the probability of initiating foraging. Octopamine(More)
Efficient division of labor is one of the main reasons for the success of the social insects. In honey bees the division of labor is principally achieved by workers changing tasks as they age. Typically, young adult bees perform a series of tasks within the colony before ultimately making the transition to foraging outside the hive for resources. This(More)
Levels of the biogenic amines dopamine, serotonin, and octopamine were measured in different brain regions of adult worker honey bees as a function of age-related division of labor, using social manipulations to unlink age and behavioral state. In the antennal lobes, foragers had higher levels of all three amines than nurses, regardless of age. Differences(More)
Forager honey bees have high circulating levels of juvenile hormone (JH) and high brain levels of octopamine, especially in the antennal lobes, and treatment with either of these compounds induces foraging. Experiments were performed to determine whether octopamine acts more proximally than JH to affect the initiation of foraging behavior. Bees treated with(More)