IEEE Trans Biomed Circuits Syst. 2018 Feb;12(1):47-57. doi: 10.1109/TBCAS.2017.2753541. Epub 2017 Oct 12.
It is believed that brain-like computing system can be achieved by the fusion of electronics and neuroscience. In this way, the optimized digital hardware implementation of neurons, primary units of nervous system, play a vital role in neuromorphic applications. Moreover, one of the main features of pyramidal neurons in cortical areas is bursting activities that has a critical role in synaptic plasticity. The Pinsky-Rinzel model is a nonlinear two-compartmental model for CA3 pyramidal cell that is widely used in neuroscience. In this paper, a modified Pinsky-Rinzel pyramidal model is proposed by replacing its complex nonlinear equations with piecewise linear approximation. Next, a digital circuit is designed for the simplified model to be able to implement on a low-cost digital hardware, such as field-programmable gate array (FPGA). Both original and proposed models are simulated in MATLAB and next digital circuit simulated in Vivado is compared to show that obtained results are in good agreement. Finally, the results of physical implementation on FPGA are also illustrated. The presented circuit advances preceding designs with regards to the ability to replicate essential characteristics of different firing responses including bursting and spiking in the compartmental model. This new circuit has various applications in neuromorphic engineering, such as developing new neuroinspired chips.
人们相信,通过电子学和神经科学的融合,可以实现类脑计算系统。在这种方式下,作为神经系统基本单元的神经元的优化数字硬件实现,在神经形态应用中起着至关重要的作用。此外,皮质区锥体神经元的主要特征之一是爆发活动,它在突触可塑性中起着关键作用。Pinsky-Rinzel 模型是 CA3 锥体神经元的一个非线性双室模型,在神经科学中被广泛应用。在本文中,通过用分段线性逼近替换其复杂的非线性方程,提出了一种改进的 Pinsky-Rinzel 锥体模型。接下来,为简化模型设计了一个数字电路,以便能够在低成本数字硬件(如现场可编程门阵列(FPGA))上实现。对原始模型和所提出的模型都在 MATLAB 中进行了仿真,并对简化模型的数字电路进行了仿真,以验证结果的一致性。最后,还说明了在 FPGA 上的物理实现结果。与之前的设计相比,所提出的电路在复制包括爆发和尖峰在内的不同放电响应的基本特征方面具有优势,这在神经形态工程中有广泛的应用,例如开发新的神经启发式芯片。