Spike train processing by a silicon neuromorph: the role of sublinear summation in dendrites.

نویسندگان

  • D P Northmore
  • J G Elias
چکیده

A dendritic tree, as part of a silicon neuromorph, was modeled in VLSI as a multibranched, passive cable structure with multiple synaptic sites that either depolarize or hyperpolarize local "membrane patches," thereby raising or lowering the probability of spike generation of an integrate-and-fire "soma." As expected from previous theoretical analyses, contemporaneous synaptic activation at widely separated sites on the artificial tree resulted in near-linear summation, as did neighboring excitatory and inhibitory activations. Activation of synapses of the same type close in time and space produced local saturation of potential, resulting in spike train processing capabilities not possible with linear summation alone. The resulting sublinear synaptic summation, as well as being physiologically plausible, is sufficient for a variety of spike train processing functions. With the appropriate arrangement of synaptic inputs on its dendritic tree, a neuromorph was shown to discriminate input pulse intervals and patterns, pulse train frequencies, and detect correlation between input trains.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Temporal Processing in Artificial Dendritic Tree Neuromorphs

The artificial dendritic tree, as part of a silicon neuromorph, is modelled as a multibranched, passive cable structure. Synaptic activations are either depolarizing (excitatory), hyperpolarizing (inhibitory), or shunting. Contemporaneous synaptic activation at widely separated sites on the tree result in linear summation of their effects, as do neighboring excitatory and inhibitory activations...

متن کامل

Summation of excitatory and inhibitory synaptic inputs by motoneurons with highly active dendrites.

We investigated summation of steady excitatory and inhibitory inputs in spinal motoneurons using an in vivo preparation, the decerebrate cat, in which neuromodulatory input from the brain stem facilitated a strong persistent inward current (PIC) in dendritic regions. This dendritic PIC amplified both excitatory and inhibitory synaptic currents two- to threefold, but within different voltage ran...

متن کامل

Input summation by cultured pyramidal neurons is linear and position-independent.

The role of dendritic morphology in integration and processing of neuronal inputs is still unknown. Models based on passive cable theory suggest that dendrites serve to isolate synapses from one another. Because of decreases in driving force or resistance, two inputs onto the same dendrite would diminish their joint effect, resulting in sublinear summation. When on different dendrites, however,...

متن کامل

Contribution of sublinear and supralinear dendritic integration to neuronal computations

Nonlinear dendritic integration is thought to increase the computational ability of neurons. Most studies focus on how supralinear summation of excitatory synaptic responses arising from clustered inputs within single dendrites result in the enhancement of neuronal firing, enabling simple computations such as feature detection. Recent reports have shown that sublinear summation is also a promin...

متن کامل

Temporal integration can readily switch between sublinear and supralinear summation.

Temporal summation at dendrites of cultured rat hippocampal neurons was examined as a function of the interval separating two dendritic inputs. A novel method that relies on single-mode optical fibers to achieve rapid photorelease of glutamate was developed. Dendritic excitation achieved with this approach resembles that associated with miniature excitatory postsynaptic currents (mEPSCs), but t...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:
  • Neural computation

دوره 8 6  شماره 

صفحات  -

تاریخ انتشار 1996