Tradeoffs and Constraints on Neural Representation in Networks of Cortical Neurons

Abstract

Neural representation is pivotal in neuroscience. Yet, the large number and variance of underlying determinants make it difficult to distinguish general physiologic constraints on representation. Here we offer a general approach to the issue, enabling a systematic and well controlled experimental analysis of constraints and tradeoffs, imposed by the physiology of neuronal populations, on plausible representation schemes. Using in vitro networks of rat cortical neurons as a model system, we compared the efficacy of different kinds of "neural codes" to represent both spatial and temporal input features. Two rate-based representation schemes and two time-based representation schemes were considered. Our results indicate that, by large, all representation schemes perform well in the various discrimination tasks tested, indicating the inherent redundancy in neural population activity; Nevertheless, differences in representation efficacy are identified when unique aspects of input features are considered. We discuss these differences in the context of neural population dynamics.

Repeated stimulation of cultured networks of rat cortical neurons induces parallel memory traces

“…The finding that stimulus responses stabilized, probably means that subsequent presentation of the cue reactivated the trace and did not interfere with the established activity-connectivity equilibrium. Marom and coworkers showed that repeated stimulation of cultured cortical networks induced site-specific responses that enabled deduction of the stimulation site during up to 24 h (Shahaf et al 2008;Kermany et al 2010). This further supports the view that presentation of the original cue reactivates the trace.…”

Quantitative examination of stimulus-response relations in cortical networks in vitro

“…The late component is sensitive to glutamate receptor blockers, supporting a polysynaptic origin (Jimbo et al 2000). It is this component that reflects how a local stimulus will eventually invade the network, and that thus should have predictable dynamics (Kermany et al 2010). Understanding what influences the properties of the polysynaptic response is therefore crucial for a defined interaction with neuronal networks.…”

Simulation of Spontaneous Activity in Neuronal Cultures with Long-Term Plasticity

“…В современных работах по изучению электрофизиологической активности нейрональных культур in vitro особое внимание уделяется феномену спонтанной пачечной активности [1][2][3][4][5][6][7][8][9][10]. Популяционной пачкой (или просто пачкой) активности культуры называется явление резкого возрастания активности групп нейронов в течение короткого промежутка времени.…”

“…В работе [5] исследуется временной порядок вовлечения нейронов в вызванную электрической стимуляцией пачку активности. Авторы работы [6] сравнивают несколько методов анализа активности сетей нейронов, основанных либо на частотной характеристике ответа нейронов на стимулы (например, общее количество активаций нейрона в течение некоторого времени после стимула), при этом теряется временной порядок активации различных нейронов, либо на учете времени первой активации каждого из рассматриваемых нейронов. Для каждого из методов анализа обсуждается его наилучшая область применения.…”