The Core Apoptotic Executioner Proteins CED-3 and CED-4 Promote Initiation of Neuronal Regeneration in Caenorhabditis elegans

Laser severing of individual axons in the nematode Caenorhabditis elegans revealed that the apoptotic executioner caspase CED-3 and its regulator CED-4/Apaf-1 play an unexpected beneficial role in promoting axonal regeneration

Cocaine Serves as a Peripheral Interoceptive Conditioned Stimulus for Central Glutamate and Dopamine Release

Intravenous injections of cocaine HCl are habit-forming because, among their many actions, they elevate extracellular dopamine levels in the terminal fields of the mesocorticolimbic dopamine system. This action, thought to be very important for cocaine's strong addiction liability, is believed to have very short latency and is assumed to reflect rapid brain entry and pharmacokinetics of the drug. However, while intravenous cocaine HCl has almost immediate effects on behavior and extracellular dopamine levels, recent evidence suggests that its central pharmacological effects are not evident until 10 or more seconds after IV injection. Thus the immediate effects of a given intravenous cocaine injection on extracellular dopamine concentration and behavior appear to occur before there is sufficient time for cocaine to act centrally as a dopamine uptake inhibitor. To explore the contribution of peripheral effects of cocaine to the early activation of the dopamine system, we used brain microdialysis to measure the effects of cocaine methiodide (MI)—a cocaine analogue that does not cross the blood brain barrier—on glutamate (excitatory) input to the dopamine cells. IP injections of cocaine MI were ineffective in cocaine-naïve animals but stimulated ventral tegmental glutamate release in rats previously trained to lever-press for cocaine HCl. This peripherally triggered glutamate input was sufficient to reinstate cocaine-seeking in previously trained animals that had undergone extinction of the habit. These findings offer an explanation for short-latency behavioral responses and immediate dopamine elevations seen following cocaine injections in cocaine-experienced but not cocaine-naïve animals

Strong coupling of alkali spins to noble-gas spins with hour-long coherence time

Nuclear spins of noble gases can maintain coherence for hours at ambient conditions owing to their extraordinary isolation by the enclosing, complete electronic shells. This isolation, however, impedes the ability to manipulate and control them by optical means or by physical coupling to other spin gases. Here we experimentally achieve strong coherent coupling between noble-gas spins and the optically-accessible spins of alkali-metal vapor. Stochastic spin-exchange collisions, underlying the coupling, accumulate to a coherent periodic exchange of spin excitations between the two gases. We obtain a coupling rate 10 times higher than the decay rate, observe the resultant avoided crossing in the spectral response of the spins, and demonstrate the external control over the coupling by magnetic fields. These results open a route for efficient and rapid interfacing with noble-gas spins for applications in quantum sensing and information

Long-Lived Entanglement Generation of Nuclear Spins Using Coherent Light

Nuclear spins of noble-gas atoms are exceptionally isolated from the environment and can maintain their quantum properties for hours at room temperature. Here we develop a mechanism for entangling two such distant macroscopic ensembles by using coherent light input. The interaction between the light and the noble-gas spins in each ensemble is mediated by spin-exchange collisions with alkali-metal spins, which are only virtually excited. The relevant conditions for experimental realizations with ^{3}\text{He} or ^{129}\text{Xe} are outlined

Constraints on axion-like dark matter from a SERF comagnetometer.

Ultralight axion-like particles are well-motivated relics that might compose the cosmological dark matter and source anomalous time-dependent magnetic fields. We report on terrestrial bounds from the Noble And Alkali Spin Detectors for Ultralight Coherent darK matter (NASDUCK) collaboration on the coupling of axion-like particles to neutrons and protons. The detector uses nuclei of noble-gas and alkali-metal atoms and operates in the Spin-Exchange Relaxation-Free (SERF) regime, achieving high sensitivity to axion-like dark matter fields. Conducting a month-long search, we cover the mass range of 1.4 × 10-12 eV/c2 to 2 × 10-10 eV/c2 and provide limits which supersede robust astrophysical bounds, and improve upon previous terrestrial constraints by over two orders of magnitude for many masses within this range for protons, and up to two orders of magnitude for neutrons. These are the sole reliable terrestrial bounds reported on the coupling of protons with axion-like dark matter, covering an unexplored terrain in its parameter space