Many neural networks dynamically transition from one type of activity to another. Most studies designed to determine how task switching occurs at the circuit or cellular/molecular level have emphasized the `decision making' process that initiates one type of activity and terminates another. This research often targets `higher order' or command-like neurons. Our research demonstrates that this approach has limitations. Thus, the dynamics of task switching can be greatly impacted by the ability of a network to respond to a change in `command'. The circuit that we study is similar to many others in that its activity is configured and reconfigured by modulatory neurotransmitters that exert effects that persist and create an implicit form of memory. An important general question our research addresses is; how will persistent modulation impact task switching? We address this question in the situation where the switch is between two types of `antagonistic' motor programs. Initial studies of task switching characterized a situation where there was a `negative' effect, i.e., persistent effects of neuromodulation made it impossible to task switch immediately. This `task switch cost' was observed in a situation in which it is presumably beneficial. Namely, we demonstrated that a feeding network that had repeatedly generated egestive motor programs could not rapidly switch and generate ingestive motor activity. Research proposed in this application addresses a new issue; is there a situation in which persistent neuromodulation can have the opposite effect and be `beneficial' for task switching? Taken together previous and preliminary data strongly suggest that the answer to this question is yes. Proposed experiments are designed to seek further support for this idea. In broad terms our research will provide insight into circuit and cellular/molecular mechanisms that can facilitate or impede task switching. These mechanisms are of considerable general interest since task switching is essential for most species (including humans) to cope with changes in the external environment.

Public Health Relevance

The experiments proposed in this application focus on a type of task switching in which an ongoing behavior is temporarily interrupted by a brief switch to a distinctly different type of motor activity. In this situation a quick, efficient return to the original behavior is often advantageous. Proposed experiments will characterize circuit and cellular/molecular mechanisms that facilitate this type of transition.

National Institute of Health (NIH)
National Institute of Neurological Disorders and Stroke (NINDS)
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Neurobiology of Learning and Memory Study Section (LAM)
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Gnadt, James W
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Icahn School of Medicine at Mount Sinai
Schools of Medicine
New York
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Perkins, Matthew H; Cropper, Elizabeth C; Weiss, Klaudiusz R (2018) Cellular Effects of Repetition Priming in the Aplysia Feeding Network Are Suppressed during a Task-Switch But Persist and Facilitate a Return to the Primed State. J Neurosci 38:6475-6490
Zhang, Guo; Yuan, Wang-Ding; Vilim, Ferdinand S et al. (2018) Newly Identified Aplysia SPTR-Gene Family-Derived Peptides: Localization and Function. ACS Chem Neurosci 9:2041-2053
Cropper, Elizabeth C; Jing, Jian; Perkins, Matthew H et al. (2017) Use of the Aplysia feeding network to study repetition priming of an episodic behavior. J Neurophysiol 118:1861-1870
Zhang, Guo; Vilim, Ferdinand S; Liu, Dan-Dan et al. (2017) Discovery of leucokinin-like neuropeptides that modulate a specific parameter of feeding motor programs in the molluscan model, Aplysia. J Biol Chem 292:18775-18789
Ludwar, Bjoern Ch; Evans, Colin G; Cambi, Monica et al. (2017) Activity-dependent increases in [Ca2+]i contribute to digital-analog plasticity at a molluscan synapse. J Neurophysiol 117:2104-2112
Livnat, Itamar; Tai, Hua-Chia; Jansson, Erik T et al. (2016) A d-Amino Acid-Containing Neuropeptide Discovery Funnel. Anal Chem 88:11868-11876
Yang, Chao-Yu; Yu, Ke; Wang, Ye et al. (2016) Aplysia Locomotion: Network and Behavioral Actions of GdFFD, a D-Amino Acid-Containing Neuropeptide. PLoS One 11:e0147335
Cropper, Elizabeth C; Dacks, Andrew M; Weiss, Klaudiusz R (2016) Consequences of degeneracy in network function. Curr Opin Neurobiol 41:62-67
Siniscalchi, Michael J; Cropper, Elizabeth C; Jing, Jian et al. (2016) Repetition priming of motor activity mediated by a central pattern generator: the importance of extrinsic vs. intrinsic program initiators. J Neurophysiol 116:1821-1830
Friedman, Allyson K; Weiss, Klaudiusz R; Cropper, Elizabeth C (2015) Specificity of repetition priming: the role of chemical coding. J Neurosci 35:6326-34

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