This study describes mechanisms that underlie neuronal selectivity for the direction and rate of frequency-modulated sweeps in the central nucleus of the inferior colliculus (ICC) of the pallid bat (Antrozous pallidus). This ICC contains a high percentage of neurons (66%) that respond selectively to the downward sweep direction of the bat's echolocation pulse. Some (19%) are specialists that respond only to downward sweeps. Most neurons (83%) are also tuned to sweep rates. A two-tone inhibition paradigm was used to describe inhibitory mechanisms that shape selectivity for sweep direction and rate. Two different mechanisms can create similar rate tuning. The first is an early on-best frequency inhibition that shapes duration tuning, which in turn determines rate tuning. In most neurons that are not duration tuned, a delayed high-frequency inhibition creates rate tuning. These neurons respond to fast sweep rates, but are inhibited as rate slows, and delayed inhibition overlaps excitation. In these neurons, starting a downward sweep within the excitatory tuning curve eliminates rate tuning. However, if rate tuning is shaped by duration tuning, this manipulation has no effect. Selectivity for the downward sweep direction is created by an early low-frequency inhibition that prevents responses to upward sweeps. In addition to this asymmetry in arrival times of low- and high-frequency inhibitions, the bandwidth of the low-frequency sideband was broader. Bandwidth influences the arrival time of inhibition during an FM sweep because a broader sideband will be encountered sooner. These findings show that similar spectrotemporal filters can be created by different mechanisms.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1152/jn.00021.2006 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Electronic quenching of sulfur induced by argon collisions.
Phys Chem Chem Phys
January 2025
Univ Rennes, CNRS, IPR (Institut de Physique de Rennes) - UMR 6251, F-35000 Rennes, France.
An accurate potential energy model, explicitly designed for studying scattering and treating the spin-orbit and nonadiabatic couplings on an equal footing, is proposed for the S + Ar system. The model is based on the Effective Relativistic Coupling by Asymptotic Representation (ERCAR) approach, building the geometry dependence of the spin-orbit interaction a diabatisation scheme. The resulting full diabatic model is used in close-coupling calculations to compute inelastic scattering cross sections for de-excitation from the S(D) fine structure level into the P multiplet.
View Article and Find Full Text PDFIn this paper, a high-power UV-pumped BBO optical parametric oscillator (OPO) is presented by increasing the working temperature of the nonlinear crystal to fasten the color center recovery speed and further decrease the color center density. When the working temperature of the BBO crystal was experimentally increased from 135 °C to 185 °C, the output power was scaled up from 1.20 W to 2.
View Article and Find Full Text PDFWe theoretically study how the magnetic field direction controls both the transmission rate and the group delay of the signal, as well as the second-order sideband process in a hybrid cavity-magnon optomechanical system. By tuning the direction of the bias magnetic field, either a positive or negative magnon Kerr coefficient can be achieved, leading to a corresponding shift in the magnon frequency. As a result, the transmission rate can be significantly modified, resulting in a Fano-like transparency spectrum governed by the magnetic field direction, along with a slow-to-fast light switch also influenced by that direction.
View Article and Find Full Text PDFPhotooxidation and Cleavage of Ethynylated 9,10-Dimethoxyanthracenes with Acid-Labile Ether Bonds.
J Org Chem
January 2025
Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts, 02155, United States.
This paper describes a series of 12 9,10-dimethoxyanthracene derivatives functionalized with a range of electronically diverse ethynyl substituents at the 2 and 6 positions, aimed at tuning their optoelectronic properties and reactivity with singlet oxygen (O). Optical spectroscopy, cyclic voltammetry, and density functional theory calculations reveal that the ethynyl groups decrease the HOMO-LUMO gaps in these acenes. Notably, bis(dimethylanilineethynyl) substituents increase the wavelength of absorbance onset by over 60 nm compared to 9,10-dimethoxyanthracene (DMA).
View Article and Find Full Text PDFBoosting the oxygen reduction activity on metal surfaces by fine-tuning interfacial water with midinfrared stimulation.
Innovation (Camb)
January 2025
International Joint Laboratory of Catalytic Chemistry, College of Sciences, Shanghai University, Shanghai 200444, China.
Heterogeneous catalysis at the metal surface generally involves the transport of molecules through the interfacial water layer to access the surface, which is a rate-determining step at the nanoscale. In this study, taking the oxygen reduction reaction on a metal electrode in aqueous solution as an example, using accurate molecular dynamic simulations, we propose a novel long-range regulation strategy in which midinfrared stimulation (MIRS) with a frequency of approximately 1,000 cm is applied to nonthermally induce the structural transition of interfacial water from an ordered to disordered state, facilitating the access of oxygen molecules to metal surfaces at room temperature and increasing the oxygen reduction activity 50-fold. Impressively, the theoretical prediction is confirmed by the experimental observation of a significant discharge voltage increase in zinc-air batteries under MIRS.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!