Spike frequency–dependent inhibition and excitation of neural activity by high-frequency ultrasound

Balanced excitation and inhibition determine spike timing during frequency adaptation.

In layer 4 (L4) of the rat barrel cortex, a single whisker deflection evokes a stereotyped sequence of excitation followed by inhibition, hypothesized to result in a narrow temporal window for spike output. However, awake rats sweep their whiskers across objects, activating the cortex at frequencies known to induce short-term depression at both excitatory and inhibitory synapses within L4. Alth...

Excitation of polymer-shelled contrast agents with high-frequency ultrasound.

Few experimental and complementary theoretical studies have investigated high-frequency (>20 MHz) nonlinear responses from polymer-shelled ultrasound contrast agents. Three polymer agents with different shell properties were examined for their single-bubble backscatter when excited with a 40 MHz tone burst. Higher-order harmonic responses were observed for the three agents; however, their occur...

The control of locomotor frequency by excitation and inhibition.

Every type of neural rhythm has its own operational range of frequency. Neuronal mechanisms underlying rhythms at different frequencies, however, are poorly understood. We use a simple aquatic vertebrate, the two-day-old Xenopus tadpole, to investigate how the brainstem and spinal circuits generate swimming rhythms of different speeds. We first determined that the basic motor output pattern was...

Balanced inhibition and excitation drive spike activity in spinal half-centers.

Many limb movements are composed of alternating flexions and extensions. However, the underlying spinal network mechanisms remain poorly defined. Here, we show that the intensity of synaptic excitation and inhibition in limb motoneurons varies in phase rather than out of phase during rhythmic scratchlike network activity in the turtle. Inhibition and excitation peak with the total neuron conduc...

Balanced Inhibition and Excitation Drives Spike Activity in Spinal Half-Centers