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Release Notes



Windows 11 - Synapse v98 now supports Windows 11. See Tech Note 2301 for installing Optibit interface drivers.

Major Changes and Improvements

New Hardware and Gizmos!

Changes to Gizmo Defaults

  • Fiber Photometry clip threshold is now 9.0 V

  • Smooth Scrolling is disabled by default

  • Period and Width parameters for iM PWM outputs have been replaced with Base Frequency and Duty Cycle. The Pynapse setPeriod and setWidth API functions have been replaced by setDutyCycle

Miscellaneous Improvements

Electrical Stim Driver Gizmo

  • Added PulseAct output signal
Bug Fixes
  • Ultrasonic Stimulation - fixed the max duration (1e7 ms)

  • Channel Mapper - ZCA-OMN32 map was inverted

  • Pulse Train Generator, Audio Stimulation, Electrical Stimulation, Electrical Stim Driver, File Stimulation - Fixed Period parameter epoc storage when using jitter

  • PCA Sorter - Fixed monitor compatibility with RZ6 DACs

  • IZV Hal - Fix for using four sub-stimulators and multiple switching headstages

  • User Gizmos - Fix when using long user gizmo names

  • File Stimulation - The file "ID" parameter maximum value updates when the file list changes

  • RZ Digital I/O - Allow multiple gizmos to read digital inputs without warning

Version 98-r51248 (2023/04/19)

Miscellaneous Improvements
  • Synapse
    • Improved support for iCon iX6 device
    • Improved the Web Updater
  • Pynapse
    • Minor Pynapse Controls layout updates
  • ActiveX
    • Added support for UZ3 interface
Bug Fixes
  • Synapse
    • Fixed PWM resolution selection on iCon iMn devices (removed PWM from iM10)
  • Pynapse
    • Fixed input buffer reads
  • Fiber Photometry Gizmo
    • Writes to Frequency and Level from SynapseAPI properly update the UI widgets

Version 98-r51739 (2023/07/23)

Miscellaneous Improvements
  • Synapse
    • Added support for iCon iV2 video capture device
    • Added support for PS2 photosensor
    • Improved support for iCon iX6 device
  • OpenScope
    • Added video playback for iV2

Version 98-r51878 (2023/08/21)

Miscellaneous Improvements
  • Synapse
    • Fixed iV2 bug when creating reference videos for two cameras
    • Fixed iV2 Standby Mode support
    • Hide Dac-2 options for iMn devices with one DAC output
  • zBusMon
    • Fixed crash issue when updating multiple RZ devices



Licensing - Synapse v96 has a new licensing model. See Synapse Licensing for more information.

New Installer Names - 'Synapse Essentials' is now 'Synapse'. 'Synapse Suite' is now two separate packages: 'Synapse' and 'SynapseExtras'.

Major Changes and Improvements

New Hardware and Gizmos!

  • iCon Behavioral Controller - Support for the iCon to interface with behavioral hardware components

  • Python Coding Gizmo - Major updates to Pynapse gizmo for direct iCon integration, with new plotting, experiment design, and progress tracking features added. If you have Pynapse experiments designed in v95 please contact TDT.

  • Switching Headstage - Support for the new ZC-SW switching headstage.

  • Added online impedance checking for PZ5 and Subject Interface (IZV, PZA, and PZD).

  • New User Gizmos for simple but common processing tasks in the Custom → TDT gizmo category.

Changes to Gizmo Defaults

  • The 'Tick' store is enabled by default in the RZ options and plotted

  • Audio Stimulation and Ultrasonic Stimulation Gizmos - the Phase Sync option is 'Sync to Stim' by default

  • Audio Stimulation - unit text for WaveAmp parameter is now 'dBV' to accurately reflect the units

  • Fix duplicate epoc names across multiple RZ/RX digital IO outputs

  • Fiber Photometry Gizmo - Driver-3 defaults to 530 Hz for better 50 Hz power line compatibility.

  • Medusa4Z is default RAn HAL on the Rig Editor auto-detection.

Miscellaneous Improvements

Rig Editor

  • Rig editor properly auto-detects PZ5 configurations

Experiment Dialog

  • Can now sort experiments by Date Created and Date Modified

Electrical Stim Driver Gizmo

  • EStim Driver can now save parameters 'On Pulse'

New RPvdsEx Components

  • New MCiShift, MCiAnd, MCiOr, AndOr components

Pulse Train Generator Gizmo

  • Added checkbox to mute output at runtime


  • Use the new View → 'Show Epocs on Time Navigator' menu option to hide epocs from timeline for improved graphical performance while replaying long recordings.

  • AVI file names no longer need the entire block name as a prefix. Load video files named Cam#.avi and Vid#.avi files from the network.


  • SynapseAPI now returns error codes if a call fails

  • Writes to User Gizmo parameters are sent right away

MRI Processing Gizmo

  • MRI pro and Neural Stream processor check device sampling rate to match to store rate

PZ Hardware

  • PZA now has clip + activity LED options, like PZ5 Analog

  • PZD now has headstage detect LED options, like PZ5 Digital

Fiber Photometry Gizmo

  • The Fiber Photometry Gizmo has an option to raise the lowpass filter cutoff for TEMPO (voltage sensor photometry).

Parameter Sequencer

  • Click any row or header during runtime to set that sequence or manually present that row.

Tank Files

  • The StoresListing.txt file saved in the block contains more summary information on data stores in the recording.

  • Channel map CSV file(s) are included in TIN file in the block folder.


  • Added default Pynapse environment as a setting in the Preferences dialog

  • Error messages during mode change are more user-friendly

  • Synapse in-app help link goes to documentation website first

Bug Fixes
  • Channel Mapper - doesn't forget upper map channels when lowering the channel count on the input

  • Pulse Train Generator - was not applying correct initial period at run time

  • If the flow plot settings don't save properly, they are automatically reset on next recording

  • Allow multiple instances of MRI Processing Gizmo in same experiment

  • RZ Port C grouping bug fix when not inverting inputs

  • IZV - Fixed 'Serial' mode across multiple banks

  • Parameter Sequencer - Fixed 'New' button for Parameter and Sequence tabs

  • Pulse Generator - fixed min/max control limits

Version 96-r48847 (2022/02/04)

Miscellaneous Improvements
  • Synapse
    • Added RS4 runtime status monitor
    • Temporary files are permanently deleted, not sent to Recycle Bin
    • Experiment list view is now the default
    • Auto-detect PZn on DSPM
    • Auto-detect SIM, iCon, or PZn device on DSPQ optical card
  • Pynapse
    • Automatically install a default python package
  • Fiber Photometry Gizmo
    • Added storage sampling rate slider for demodulated and calculated signals
  • Electrical Stim Driver Gizmo
    • Added 'ChargeParams' parameter to adjust all biphasic waveform parameters (T1, Td, T2, L2) in a single call
  • User Input Gizmo
    • Updated SynapseAPI trigger behavior, 1 to turn on 0 to turn off
Bug Fixes
  • Synapse
    • Fixed MCFIR component calculation
    • Fixed issue with Clear Session
    • Fixed PZn analog subamp impedance checking for sub amp 2 or higher
    • Fixed Parallel mode in IZV
  • Fiber Photometry Gizmo
    • Fixes visual issue with offset spin box step size
    • Fixed issue with setting difference source in calculated outputs
  • Pulse Train Generator Gizmo
    • Fixed issue with 'Timer' mode
  • Electrical Stim Driver Gizmo
    • Fixed SynapseAPI trigger in strobe limited mode
  • Fixed v96 RXn microcode
  • Corpus
    • Fixed tone generator component
  • OpenBridge
    • Fixed issue with NEX export
  • Pynapse
    • Fixed issue with input buffers

Version 96-r49154 (2022/02/24)

Bug Fixes
  • Synapse
    • Fixed iM10 White Noise list indexing


Major Changes and Improvements

New Gizmos!

  • Python Coding Gizmo - A gizmo for tightly integrating Python coding into your Synapse experiment. With Pynapse you can:

    • Control your experiment flow
    • Build and deliver stimuli
    • Run complex behavioral paradigms
    • Do custom analysis and visualization
  • Pulse Train Generator - Create simple or complex user-defined pulse train waveforms. Trains can be stacked or parallel. Use this gizmo for directly and dynamically controlling optogenetic stimulation.

Miscellaneous Improvements

Fiber Photometry Gizmo

  • Optimized Fiber Photometry Gizmo circuit to reduce processor usage.

  • Increased max bleaching current to 1000 mA.

Bug Fixes

RZ10 and RZ10x Fiber Photometry System

  • Some LUX LEDs have a larger leakage than expected when using the RZ10x at the 500 mA or 1000 mA range for stimulation. This doesn't affect fiber photometry users who run in the 50 mA and 200 mA ranges. The control signals are updated in v95 to resolve this.

PDF Help Link

  • Internal help link in Synapse now compatible with Adobe Reader 2020.

File Stimulation Gizmo

  • Fixed issue where first file in list was stopping one sample short during presentation.

Version 95-r43524 (2020/07/10)

Bug Fixes
  • Fiber Photometry Gizmo - Fixed max current setting during automated photobleaching.

Version 95-r43718 (2020/08/04)

Miscellaneous Improvements

New User Gizmos

Version 95-r44132 (2020/09/24)

Bug Fixes
  • Electrical Stim Driver Gizmo - Fixed StimSync when Count=1. It was previously 1 sample too short. When using a Subject Interface, this would switch into inter-stim action mode too early.


Major Changes and Improvements

New Hardware!

  • Support for the RZ10 and RZ10x Fiber Photometry System – The RZ10x has integrated Lux LEDs, photosensors, and power meters for a more streamlined fiber photometry setup

Fiber Photometry Gizmo for RZ10 and RZ10x

  • New gizmo features for RZ10 and RZ10x specific fiber photometry experiments. Now includes auto-detect of integrated LUX hardware, power meter readings, and photobleaching/ experiment timing controls (What's New document for getting started)

Version 94-r42320 (2020/02/18)

Miscellaneous Improvements


  • User Gizmos and PA5 parameters are written much faster

Fiber Photometry gizmo (for non-RZ10x users)

  • Removed 'Auto-Enable' checkbox for each driver. There is now one master control to enable lights in Outputs and Data Saving.

  • Raw stores (Fi1r) are now split up into photosensor (Fi1r) and driver (Fi1d) stores

Synapse Preferences

  • Added setting to select new hardware state behavior when making new experiment: fresh, keep, prompt.

Electrical Stim Driver gizmo

  • Waveform store disabled by default. Default target changed to IZV10.

Epoc Event Storage gizmo

  • Default setting is now 'Strobe Input'

File Stimulation gizmo

  • Added TXT and CSV file options
Bug Fixes
  • Fixed Subject Interface closed-loop compilation errors and erroneous timing errors on mixed SIM boards
  • Fixed Neural Stream Processor issue with adjusting filter frequencies at runtime
  • Electrical Stim Driver gizmo
    • Fixed monopolar stim – stim duration was fixed at 2 ms
    • Fixed parameter table – adjusted to V instead of mV when IZ2 target in Voltage mode
    • Fixed channel count for >24 channels to IZ2.
  • Fixed Corpus Counter and DSPP + PZ5 emulation
  • Synapse Feedback button URL link is no longer broken
  • Fixed Pulse Generator gizmo API control of 'Enable' parameter
  • Adjusted Ultrasonic Stimulation gizmo max duration based on processor sampling rate


Major Changes and Improvements

New Gizmos!

  • MRI Recording Processor - MRI artifact rejection filters for cleaning continuous single unit and LFP signals during magnet switching or other large sources of artifacts.

New Hardware!

Gizmo Slides

  • Gizmo Slides are a user dialog in Synapse that provides an overview of what each gizmo does and the common connections they have

Legacy Circuits now support Gizmo Control Widgets and Storage Gizmos

  • Add gizmoControl widgets and Storage Macros in Legacy circuits to control circuit parameter tags and see stored data in Synapse

Parameter Sequencer Custom Timer

  • Added timer column to Parameter Sequencer to have explicit control and complete flexibility of when each presentation occurs

Version 92-r40727 (2019/06/13)

Miscellaneous Improvements

Electrical Stim Driver

  • Added API parameters for biphasic wave construction - T1, Td, T2, L2

  • Electrical Stim Driver detects SIM voltage mode and changes units accordingly

Parameter Sequencer

  • Faster pasting and more options in CSV table

  • Fixes to calculator and table

  • Can change sequencer headers from 'Seq-N' to custom identifier

Lab Rat

  • Fake Brain 'Stim Sync' now working with external and gizmo strobe input


  • Added clip min/max parameters for EDF exporting to improve resolution


  • 'Auto Plot New Block' option in Control menu automatically selects new block when in Track mode

Fiber Photometry Gizmo

  • New defaults:

    • Low pass changed from 3 Hz to 6 Hz
    • Clip Threshold changed from 3.5 V to 7 V
    • Light driver DC Offset changed from 80 mA to 20 mA
    • Allow user to set required sampling rate if higher sampling frequencies are needed

Runtime Recording Notes

  • Epoc timestamps for note events now show up on Flow Plot

Revision Log

  • User can mark experiment versions as 'stable' in revision log dialog. Useful if you are continually editing an experiment but want to revert to a known good state.

File Stim gizmo

  • 'FileList' parameter added. This returns list of loaded file names when called through API. This list also gets saved in the *.tin file of each recording block

Compiler Optimizer

  • Now On by default in new installations
  • Increased 'Processing' slider limit when enabled

Keyboard shortcut

  • can use F7 hot key to compile in Synapse (shift + F7 to revert)

Stim Gizmos

  • Increased maximum values for several options in the parameter tables
Bug Fixes
  • Fixed Electrical Stim Driver gizmo pulse timing - there were two extra samples at the end for Td and T2
  • IZ2H/IZ2MH voltage scale factor fixed
  • Corpus clock inaccuracy fixed
  • The extra low pass filter option 'Add DSP filter' to remove high frequency digital noise on digital banks might not have worked with mixed analog/digital PZ5 configurations or multiple logical amplifiers
  • RPvdsEx components ArtReject, Counter, TSlope, and IZ2 emulator fixed in Corpus
  • AudioStim/UltrasonicStim set phase to ±180 degrees fixed
  • Persistence changes in Standby mode is now saved to the database
  • Fixes for PO8e HAL integer streaming modes
  • Epoc Storage gizmo – fixed value change mode for integer inputs


Special Notes When Updating

To see the deprecated gizmos in the list of available gizmos, select the option in Menu → Preferences → Show Deprecated Gizmos.

Major Changes and Improvements

New Gizmos!

  • Signal Accumulator - Computes running sums and averages over a defined window, and allows advanced plotting and thresholding of these values
  • Electrical Stim Driver - A more powerful version of the Electrical Stimulation gizmo that allows up to 4 independent stim patterns (voices) with built-in channel selector for controlling IZ2 stimulator.
  • Ultrasonic Stimulation - A stripped down version of the Audio Stimulation gizmo designed to run at higher frequencies on the RZ6 processor
  • User Input - Bring external digital inputs (e.g. button press) or software button presses into Synapse for marking timestamp events and controlling logic flow

Multiple run-time plots and advanced layout saving

New run-time plots added to Strobed Data Storage gizmo

Added API access directly to gizmo ports, including RZ inputs and outputs

  • Most gizmo outputs can be read directly using the API instead of going through a User Gizmo with SynapseAPI Access

Version 90-r39052 (2018/09/20)

Miscellaneous Improvements

Parameter Sequencer

Unary Processor

  • Added a visual schematic to better understand the signal flow and how the parameters are used.
  • When converting to logic signal, the floating point signals before the logic test are also available on the output. Example: If making an RMS threshold detector, you can visualize both the threshold crossings and the RMS value used for the detection.

PCA Spike Sorting

  • Now runs at up to 100 kHz sampling rate. RZ6 users can combine high frequency audio stim and low channel count spike recording on one device.

MATLAB SDK link to SDK page

  • Added functions to TDTbin2mat to apply digital filters (TDTdigitalfilter) and threshold continuous streams into snippets (TDTthresh).
  • Added 'COMBINE' option to TDTbin2mat which can merge snippets of data that was stored in Strobe Controlled mode using the Strobed Data Storage gizmo back into its constituent streams.
  • Expanded STORE option to include cell array of strings.


  • New Compiler Optimizer option in Advanced tab removes unused circuit components during compilation.


  • Added right-click pop up dialog on parameter table values that allows easier parsing of input values, such as E-notation.

Epoch Event Storage

  • Updated the UI and added 'On Change' mode that stores the value whenever a change is detected on the input value.

Selector Gizmo

  • Added 'Logical Output' checkbox when selecting bit fields or sort codes. In Bit Fields mode, logic output is 1 if selected field's value equals selected sort code. In Sort Codes mode, logic output is 1 if selected field's value is nonzero.

Neural Stream Processor Gizmo

  • Output link is now always enabled.

Pulse Generator Gizmo

  • Added 'Minimum' Duty Cycle option which makes output pulse a single sample.

Oscilloscope Gizmo

  • Run-time settings are kept when switching to Idle, including threshold(s) and plot range, so your design and run-time interfaces are always synchronized. The new Accumulator gizmo also does this.


  • Optionally allocate more DSP memory when streaming very high channel count data.
Bug Fixes
  • Neural Stream Processor high pass filters below 2 Hz were not applied correctly (no high pass filter was applied).
  • Fixed 'Save to Disk' option in all gizmos that do data storage so that nothing about the store is saved to disk when this option is disabled.
  • Fixed cases where Corpus becomes unresponsiveness
  • Tetrode Spike Sorting - Fix when deleting sort codes
  • Better handling of very high and very low screen resolutions
  • Bug fixes for some lesser used Corpus emulated DSP components
  • Fixed Mapper crash bug when using multiple custom maps
  • Fixed Unary Processor multi-channel convert to logic


Special Notes When Updating

  • Make sure all gizmo names are less than 15 characters long.
  • Individual Referencing Mode in PZ5 maps only the odd channels to the Amplifier output.
  • LFP gizmo will be replaced by Neural Stream Processor gizmo in the next release.
  • Stimulation gizmos no longer fire automatically when attached to #Reset signal.

Major Changes and Improvements

New Gizmos!

  • Neural Signal Referencer - Removes common signals from a multi-channel stream of neural signals. Can do single or multi-channel referencing on all channels or independent sub-groups of channels.
  • Timer - Measures the elapsed time between logical events or calculates the frequency of events.
  • Neural Stream Processor - Filters and stores single or multi-channel biopotential waveforms. Replaces the LFP Gizmo.
  • Pulse Generator - Creates a simple user-defined pulse train. Useful for turning on/off the fiber photometry light driver outputs or controlling optogenetic stimulation.
  • Delay - Adds a fixed or dynamic delay to any signal.

Support for UZ3 Fiber Optic to USB 3.0 interface.

Synapse Lite and support for Lab Rat platform (LR10).

Version 88-r38174 (2018/04/23)

Miscellaneous Improvements
  • New interface button on upper right to provide direct feedback to TDT.
  • New notes interface in RZ and RX devices. Save string notes and timestamps into the tank and a readable Notes.txt log in the block file. Can also create notes through the SynapseAPI.
  • StoresListing.txt file in block folder contains information about what gizmo created each store.
  • Epoch store gizmo can now be triggered on value change.
  • Electrical Stimulation gizmo shows a plot of the pulse and burst during design time.
  • Parameter Sequencer lets you automatically start the sequence when the block starts and automatically store the recording when the sequence is done.
  • Button presses and all SynapseAPI calls to write to buttons are passed directly to circuit with minimum delay.
  • Each gizmo can be set to 'Fresh' persistence on a per-gizmo basis. When selected, the run-time persistence will be ignored and the default experiment values for that gizmo will be used every recording.
  • User run-time layout can be loaded from pre-existing experiment run.
  • User gizmo - gizmoControl macro allows duplication of controls for parameter tags inside iterate box.
  • The RV2 has fewer communication delays.
  • PCSort/BoxSort/TetSort can show just one channel/tetrode.
  • 'Tick' store can now be disabled to save cycle usage.
  • Experiments are lockable to prevent accidental edits.
  • "Clean Storage" menu lets you remove old Preview history and empty tanks to clean up the database and hard drive.
  • Stimulation gizmos have the continuous store enabled by default.
  • Run-time channel map editing is disabled.
Bug Fixes
  • Fixed phase sync in audio stimulation gizmo.
  • LFP HP filter API setting was off by one.
  • Can connect User Gizmos to SortCodes output links directly now.
  • Fixed bug in Smooth Scrolling data plot when paused.
  • Fix RVMap for invalid parameters.
  • Allow Parameter Sequencer gizmo to have more than 10000 items.
  • Make sure duplicate Fiber Photometry gizmos create unique stores.
  • Fix off by one sample bug in File Stimulation gizmo.
  • Fix for initial value when gizmoControl is a Logic type.
  • Properly limit the ZD headstages to 25 kHz sampling rate.
  • Fix for stimulation gizmos missing first trigger when in Strobe controlled modes.


Major Changes and Improvements

Cluster Mode

  • Using PO5c interface card, divide complex tasks across multiple workstations, screens, and users. Easily scale to 2,000 recording channels and beyond, all time-locked to a single master clock. Or split high channel count recording and custom stim paradigms across two machines.

Version 86-r36093 (2017/07/19)

Miscellaneous Improvements
  • Data Plot
    • New smooth scrolling option
    • Better memory constraint handling
  • PZn HAL
    • Added clip and activity LED checkboxes.
  • LFP gizmo
    • Added option to turn off high-pass filter.
  • PCSort, BoxSort, TetSort gizmos
    • Plotting routines are faster.
    • Snippet storage is more efficient in v86 microcode.
  • SynapseAPI
    • Added getMemos function to read log files.
    • Added getGizmoParent function.
    • Updated getKnownBlocks function to return all known blocks in Synapse database.
  • Updated Preferences Dialog to give user more control under the hood.
  • Improved accuracy of automatic impedance checker for IZn HAL.
  • User can export the Subject, Experiment, and User logs directly to CSV files. They are also accessible through SynapseAPI.
  • Added PA5 HAL.
  • Added menu options to delete empty tanks from disk.
Bug Fixes
  • Fixed bug where low-pass filter was applied to PZ2 and PZ4 devices.
  • Fixed Unary Processor preset order.
  • Increased Parameter Sequencer gizmo interval precision and maximum value.
  • Fixed bug in Sort Code output from BoxSort/TetSort gizmos when connecting to Sort Binner gizmo.
  • Fixed RX8 analog I/O montage.
  • Fixed RX/RZ grouped digital I/O inversion.
  • Fixed PCSort unsorted vs outlier sort code identifier.
  • Miscellaneous UI fixes.
  • Warn user when changing name of gizmo so that proper persistence can load.