NeuroLog System Application Notes

Please note that as well as the modules indicated below, each application will require a NeuroLog Case & Power Supply Unit (NL900D or NL905) and possibly some interconnection and output cables or cable adaptors. Just click on the application note of interest to download a PDF file which details the modules required and how they are set up and interconnected.

Signal Amplification

At the heart of the NeuroLog system range are the many possible amplification modules, which can be used to make intracellular or extracellular microelectrode recordings; multi-channel EMG, EEG or ECG recordings or recordings from strain gauges or pressure transducers.

• Extracellular AC recording system with spike discrimination and audio monitoring.
  Modules Used: NL100AK, NL104A, NL106, NL125, NL201, NL120S, NL985S
• The NL100RK – Record from and then electrically lesion your recording site without moving or disconnecting the electrode.
  Modules Used: NL100RK, NL104A
• How to avoid ground loops when recording from multiple NL100AK AC preamplifier headstages.
  Modules Used: NL100AK (x2 or more)
• A typical intracellular (DC) recording configuration.
  Modules Used: NL102G, NL412, NL125, NL106, NL304, NL405 (x2)
• 4-Channel isolated amplifier system with filtering and signal conditioning.
  Modules Used: NL844, NL820A, NL135, NL144, NL530
• Measurement of physiological pressures with the NeuroLog System.
  Modules Used: NL108A Other items: NL108T2, NL108T4, NL108L2, NL108L4, NL108D4

Triggering & Pulse Generation

Here are just some ways that NeuroLog modules can be utilized to produce complex pulse protocols with full control over the timing characteristics. These pulses can be used to trigger other equipment, including electrical stimulators. Other pulse generation protocols featuring stimulation are given in the Electrical Stimulation Section.

• Triggering a stimulator at a set time after a set number of pulses within a burst.
  Modules Used: NL304, NL405 (x2), NL301, NL603
• A set number of bursts of pulses with control of burst duration/repetition & output frequency/width.
  Modules Used: NL603 (x2), NL304, NL405, NL301
• A regular burst of pulses with control of burst duration/repetition and output frequency/width.
  Modules Used: NL304, NL405, NL301
• Triggering a stimulator a set time after EMG activity.
  Modules Used: NL703, NL201, NL405
• A versatile stimulus timing protocol: Set number of trains; set number of bursts in a train and set number of pulses in a burst.
  Modules Used: NL603 (x4), NL304 (x2), NL301, NL405
• A regular burst of pulses with control over burst frequency, pulses/burst, pulse width & frequency.
  Modules Used: NL301, NL304, NL603, NL405

Signal Conditioning Filtering & Processing

Single & multi-channel filters and signal conditioning units can be used to remove unwanted components/frequencies from biological signals prior to acquisition. In addition, some of the NeuroLog modules can be used to carry out simple processing tasks.

• Connection of four NL125/6 filters between NL820A Isolator and NL530 Conditioner.
  Modules Used: NL820A, NL125 (x4), NL530
• Using an analogue output to monitor the instantaneous interval between an irregular series of input pulses.
  Modules Used: NL304, NL601

Electrical Stimulation

The NeuroLog System includes a battery powered constant current stimulus isolator (NL800A) which can be controlled by various modules within the range. In addition, the output pulses produced by the NeuroLog System can be used to trigger most laboratory stimulators.

• Some examples of simple stimulator circuits.
  Modules Used: NL800A, NL510A, NL512, NL405, NL301, NL304
• Using a single trigger pulse to produce two bursts of stimuli from two stimulators with a variable delay between the bursts.
  Modules Used: NL405 (x3), NL301 (x2)
• Simple bi-phasic pulse generation of a defined duration burst.
  Modules Used: NL301, NL405 (x2), NL506, NL510A, NL800A (x2)
• Using a biphasic analogue waveform to generate an isolated biphasic voltage output from two NL800 constant current stimulus isolators.
  Modules Used: NL512, NL800A (x2)
• Using the NL405 Delay/Width Module & NL501Logic Gate to produce pairs of pulses with interval control from a single trigger input, such as the NL301Pulse Generator.
  Modules Used: NL301, NL405, NL501