Transimpedance optical preamplifier with a very low input resistance

1987 ◽  
Vol 23 (4) ◽  
pp. 138 ◽  
Author(s):  
B. Wilson ◽  
I. Darwazeh
Keyword(s):  
Input Resistance ◽  
Low Input

scholarly journals GAD67-GFP+ Neurons in the Nucleus of Roller. II. Subthreshold and Firing Resonance Properties

2011 ◽  
Vol 105 (1) ◽  
pp. 249-278 ◽  
Author(s):  
J.F.M. van Brederode ◽  
A. J. Berger
Keyword(s):  
Phase Locking ◽  
Input Resistance ◽  
Companion Paper ◽  
Spike Timing ◽  
Inhibitory Neurons ◽  
Membrane Properties ◽  
Low Input ◽  
Resonance Properties ◽  
Subthreshold Resonance ◽  
Low Pass

In the companion paper we show that GAD67-GFP+ (GFP+) inhibitory neurons located in the Nucleus of Roller of the mouse brain stem can be classified into two main groups (tonic and phasic) based on their firing patterns in responses to injected depolarizing current steps. In this study we examined the responses of GFP+ cells to fluctuating sinusoidal (“chirp”) current stimuli. Membrane impedance profiles in response to chirp stimulation showed that nearly all phasic cells exhibited subthreshold resonance, whereas the majority of tonic GFP+ cells were nonresonant. In general, subthreshold resonance was associated with a relatively fast passive membrane time constant and low input resistance. In response to suprathreshold chirp current stimulation at a holding potential just below spike threshold the majority of tonic GFP+ cells fired multiple action potentials per cycle at low input frequencies (<5 Hz) and either stopped firing or were not entrained by the chirp at higher input frequencies (= tonic low-pass cells). A smaller group of phasic GFP+ cells did not fire at low input frequency but were able to phase-lock 1:1 at intermediate chirp frequencies (= band-pass cells). Spike timing reliability was tested with repeated chirp stimuli and our results show that phasic cells were able to reliably fire when they phase-locked 1:1 over a relatively broad range of input frequencies. Most tonic low-pass cells showed low reliability and poor phase-locking ability. Computer modeling suggested that these different firing resonance properties among GFP+ cells are due to differences in passive and active membrane properties and spiking mechanisms. This heterogeneity of resonance properties might serve to selectively activate subgroups of interneurons.

Low Input Resistance CMOS Current Comparator Based on the FVF for Low-Power Applications

2016 ◽  
Vol 39 (2) ◽  
pp. 127-131 ◽  
Author(s):  
Jesus Ezequiel Molinar Solis ◽  
Marco Gurrola Navarro ◽  
Israel Mejia ◽  
Rodolfo Zola Garcia Lozano ◽  
Fernando Luna Rojas ◽  
...  
Keyword(s):  
Low Power ◽  
Input Resistance ◽  
Current Comparator ◽  
Low Input
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