Properties of the evoked spatio-temporal electrical activity in neuronal assemblies.
Properties of neural computation were studied in two types of neuronal networks: isolated leech ganglia and neuronal cultures of dissociated cortical neurons from neonatal rats. With appropriate experimental set-ups it was possible to obtain a precise description of the spread of excitation induced by specific inputs. The evoked spatio-temporal electrical activity was characterized by large variability and the electrical activity of neurons activated by the same stimulation was found to be statistically independent to a high degree. The variability presumably originates from basic properties of synaptic transmission, which is stochastic in nature. As a consequence, the large variability of the evoked spatio-temporal electrical activity appears to be a general property of neural computation and a typical feature of neuronal assemblies. It is shown, however, that the observed statistical independence of co-activated neurons may be used to reduce the effects of variability by appropriately averaging or pooling the electrical activity.
Pinato
G
G
SISSA, Trieste, Italy.
Parodi
P
P
Bisso
A
A
Macrì
D
D
Kawana
A
A
Jimbo
Y
Y
Torre
V
V
D000818:Animals; D019295:Computational Biology; D005071:Evoked Potentials / Q000502:physiology*; D009415:Nerve Net / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D051381:Rats; D013569:Synapses / Q000502:physiology*; D013997:Time Factors