This repository provides firmware and documentation for automating the Rapid Kindling (RK) protocol used in epilepsy research. Unlike versions relying on microcontroller timing, this system uses a DS3231 Real-Time Clock (RTC) to guarantee long-duration precision.
Electrical stimulation is applied to the basolateral amygdala (BLA) in rodent models using surgically implanted electrodes. The Arduino-based system initiates stimulus trains at predefined intervals, following protocols described in:
- Álvarez-Ferradas et al., Neurobiology of Disease, 2015
- Morales et al., Frontiers in Cellular Neuroscience, 2014
The system includes:
- RTC-controlled stimulation timing
- Manual start/cancel via push button
- LCD display for time and status feedback
- TTL signal output for external trigger control
Component | Description |
---|---|
Arduino Uno / Nano | Microcontroller |
DS3231 RTC Module | Precision timekeeping |
I2C LCD (16x2, addr 0x27) | Real-time display |
Push Button | Starts/cancels protocol (connected to D2) |
Relay Output | Triggers external stimulator (connected to D3) |
Bipolar Stimulus Isolator | Safely delivers stimulation current |
Square-Wave Pulse Generator | Defines waveform (frequency, amplitude) |
✅ Optional add-ons: buzzer, SD logger, multichannel expansion
The Arduino gates stimulation trains at key intervals after button-press initiation. Each train lasts 10 seconds. The exact timing replicates RK paradigms:
Elapsed Time | Event |
---|---|
00:20:00 | Stimulus 1 |
01:00:00 | Stimulus 2 |
01:40:00 | Stimulus 3 |
02:20:00 | Stimulus 4 |
03:00:00 | Stimulus 5 |
03:40:00 | Stimulus 6 |
The real-time clock ensures consistent delivery over long durations.
This system acts as an external trigger controller, not a waveform generator. The relay output sends TTL-level pulses to gate an external square-wave stimulator, configured with:
- Frequency: 50–60 Hz
- Pulse Duration: ~1 ms
- Train Duration: 10 seconds
- Current Amplitude: Subthreshold, based on post-discharge threshold (AD) testing
Stimulation is delivered via a bipolar stimulus isolator, ensuring:
- 🔒 Electrical safety and tissue protection
- 🧪 Artifact minimization during recording
- 📏 Reproducible current delivery across sessions
This modular design separates timing logic (Arduino + RTC) from waveform control (external generator), following established methodology.
- Manual start/cancel protocol interface
- Chronometer-style time display on LCD
- Status messages for each stimulation event
- Modular functions for relay control and timing conversions
- Cancelable protocol at any time via button press
Signal | Arduino Pin | Description |
---|---|---|
Push Button | D2 | Start/cancel protocol |
Relay Output (TTL) | D3 | Gates external stimulator |
DS3231 RTC | SDA/SCL | Timekeeping |
LCD Display | SDA/SCL | Displays feedback |
This system facilitates studies of epileptogenesis and neural plasticity, particularly involving:
- After-discharges (ADs)
- Seizure threshold monitoring
- Kindling progression in limbic regions
Compatible with:
- Optogenetic and chemogenetic stimulation
- Electrophysiological recording systems
- EEG and behavioral monitoring setups
All procedures follow ethical standards approved by the Bioethics Committee of the University of Valparaíso, including:
- Minimizing discomfort and stress in animal models
- Scientific justification for stimulation paradigms
- Trained personnel for animal handling
- International compliance for animal research
- Interrupt-driven timing for enhanced stability
- SD card logging of timestamps and stimulation events
- Multi-channel expansion for bilateral stimulation
- Integration with ESP32 or Teensy for wireless control
- Cloud syncing or serial logging options
Released under the MIT License. Free to use, modify, and redistribute for scientific or educational purposes.
You're welcome to:
- Improve timing logic or modularity
- Integrate new hardware or data logging
- Share experimental datasets or outcomes
- Translate documentation and expand use cases
- Álvarez-Ferradas et al., Neurobiology of Disease, 2015
- Morales et al., Front. Cell. Neurosci., 2014
- Martorell et al., Neurobiology of Disease, 2020
👨🔬 Developed by: Felipe Guiffa Gómez
📧 Email: felipe.guiffa@postgrado.uv.cl
🌍 Valparaíso, Chile