Biology subjects

Krauth, N.

Publications and source records attributed to Krauth, N..

3 recordsLinked to original sources

bioRxiv2024

A hypothalamus-brainstem circuit governs the prioritization of safety over essential needs

Animals continously adapt their behavior to balance survival and fulfilling essential needs. This balancing act involves prioritization of safety over the pursuit of other needs. However, the specific deep brain circuits that regulate safety-seeking behaviors in conjuction with motor circuits remain poorly understood. Here we identify a class of glutamatergic neurons in the lateral hypothalamic area (LHA) that target the midbrain locomotor-promoting pedunculopontine nucleus (PPN). Upon activation, this LHA-PPN pathway orchestrates context-dependent locomotion, prioritizing safety-directed movement over other essential needs such as foraging or mating. Remarkably, the neuronal activity of these circuits correlates directly with safety-seeking behavior. These circuits may respond to both intrinsic and external cues, playing a pivotal role in ensuring survival. Our findings uncover a circuit motif within the lateral hypothalamus that when recruited, prioritizes critical needs through the recruitment of an appropriate motor action.

neuroscience↗

bioRxiv2021

Dual-color optical activation and suppression of neurons with high temporal precision

A well-known phenomenon in the optogenetic toolbox is that all light-gated ion channels, including red-shifted channelrhodopsins (ChRs), are activated by blue light, whereas blue-shifted ChRs are minimally responsive to longer wave-lengths. Here, we took advantage of this feature to create a system which allows high-frequency activation of neurons with pulses of red light, while permitting the suppression of action potentials with millisecond precision by blue light. We achieved this by pairing an ultrafast red-shifted ChR with a blue light-sensitive anion channel of appropriately matching kinetics. This required screening several anion-selective ChRs, followed by a model-based mutagenesis strategy to optimize their kinetics and light spectra. Slice electrophysiology in the hippocampus as well as behavioral inspection of vibrissa movement demonstrate a minimal excitation from blue light. Of significant potential value, in contrast to existing tools, the system we introduce here allows high frequency optogenetic excitation of neurons with red light, while blue light suppression of action potentials is confined within the duration of the light pulse.

neuroscience↗

bioRxiv2020

TRACE: An unbiased method to permanently tag transiently activated inputs

A fundamental interest in circuit analysis is to parse out the synaptic inputs underlying a behavioral experience. Toward this aim, we have devised an unbiased strategy that specifically labels the afferent inputs that are activated by a defined stimulus in an activity-dependent manner. We validated this strategy in four brain areas receiving known sensory inputs. This strategy, as demonstrated here, accurately identifies these inputs.

neuroscience↗