Neuromodulation of Neuromorphic Circuits

TL;DR

This paper introduces a new input-output based methodology for neuromodulating neuromorphic circuits, allowing precise control of their excitability properties by shaping I-V curves, inspired by biological neuromodulation mechanisms.

Contribution

The proposed approach is a general, purely input-output method that controls neuromorphic circuits through voltage-controlled current sources, differing from traditional parameter tuning methods.

Findings

Enables robust and accurate control of circuit behavior

Resembles biophysical neuromodulation mechanisms

Validated through SPICE simulations of MOSFET-based circuits

Abstract

We present a novel methodology to enable control of a neuromorphic circuit in close analogy with the physiological neuromodulation of a single neuron. The methodology is general in that it only relies on a parallel interconnection of elementary voltage-controlled current sources. In contrast to controlling a nonlinear circuit through the parameter tuning of a state-space model, our approach is purely input-output. The circuit elements are controlled and interconnected to shape the current-voltage characteristics (I-V curves) of the circuit in prescribed timescales. In turn, shaping those I-V curves determines the excitability properties of the circuit. We show that this methodology enables both robust and accurate control of the circuit behavior and resembles the biophysical mechanisms of neuromodulation. As a proof of concept, we simulate a SPICE model composed of MOSFET transconductance amplifiers operating in the weak inversion regime.