Membrane characteristics of visual cortical neurons in in vitro slices

Ogawa, Tetsuro; Ito, Seisho; Katô, Hiroshi

doi:10.1016/0006-8993(81)91105-7

Cited by 17 publications

(4 citation statements)

References 9 publications

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“…The time constants of cortical neurons in the cat have been estimated in the range of 7-10 ms in slice preparations (cf. Ogawa et al, 1981;Stafstrom et al, 1984), although one group suggests that the available data are consistent with values up to 100 ms or more (Stratford et al, 1990). If most of the visual cortical neurons decreased their time constants with the sum-ofsinusoids stimulus, this would account for the decreased integration times observed.…”

Section: Discussionmentioning

confidence: 95%

Broadband temporal stimuli decrease the integration time of neurons in cat striate cortex

1992

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We have studied the responses of striate cortical neurons to stimuli whose contrast is modulated in time by either a single sinusoid or by the sum of eight sinusoids. The sum-of-sinusoids stimulus resembles white noise and has been used to study the linear and nonlinear dynamics of retinal ganglion cells (Victor et al., 1977). In cortical neurons, we have found different linear and second-order responses to single-sinusoid and sum-of-sinusoids inputs. Specifically, while the responsivity near the optimal temporal frequency is lower for the sum-of-sinusoids stimulus, the responsivity at higher temporal frequencies is relatively greater. Along with this change in the response amplitudes, there is a systematic change in the time course of responses. For complex cells, the integration time, the effective delay due to a combination of actual delays and low-pass filter stages, changes from a median of 85 ms with single sinusoids to 57 ms with a sum of sinusoids. For simple cells, the integration times for single sinusoids range from 44–100 ms, but cluster tightly around 40 ms for the sum-of-sinusoids stimulus. The change in time constant would argue that the increased sensitivity to high frequencies cannot be explained by a static threshold, but must be caused by a fundamental alteration in the response dynamics. These effects are not seen in the retina (Shapley & Victor, 1981) and are most likely cortical in origin.

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Section: Discussionmentioning

confidence: 95%

Broadband temporal stimuli decrease the integration time of neurons in cat striate cortex

1992

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“…This is clearly impossible, so we choose our word and letter lengths according to physiological criteria, taking into account factors such as integration time and temporal precision, and also according to the amount of available data, which limits the accuracy with which the word probabilities can be estimated. We use 14.8 msec words [the stimulus frame time, but also similar to the time constant of cortical neurons (Ogawa et al, 1981;Shadlen and Newsome, 1998)] and 3.7 msec letters (the frame time of the visual display, but also close to the cutoff time between short and medium ISIs), so that each word is four letters long. For these word and letter lengths, the 16 repeats of our 60.6 sec stimulus provided more than adequate amounts of data to robustly estimate the information.…”

Section: Methodsmentioning

confidence: 99%

Interspike Intervals, Receptive Fields, and Information Encoding in Primary Visual Cortex

et al. 2000

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In the primate primary visual cortex (V1), the significance of individual action potentials has been difficult to determine, particularly in light of the considerable trial-to-trial variability of responses to visual stimuli. We show here that the information conveyed by an action potential depends on the duration of the immediately preceding interspike interval (ISI). The interspike intervals can be grouped into several different classes on the basis of reproducible features in the interspike interval histograms. Spikes in different classes bear different relationships to the visual stimulus, both qualitatively (in terms of the average stimulus preceding each spike) and quantitatively (in terms of the amount of information encoded per spike and per second). Spikes preceded by very short intervals (3 msec or less) convey information most efficiently and contribute disproportionately to the overall receptive-field properties of the neuron. Overall, V1 neurons can transmit between 5 and 30 bits of information per second in response to rapidly varying, pseudorandom stimuli, with an efficiency of approximately 25%. Although some (but not all) of our results would be expected from neurons that use a firing-rate code to transmit information, the evidence suggests that visual neurons are well equipped to decode stimulus-related information on the basis of relative spike timing and ISI duration.

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“…Such studies show that, at least in a subpopulation, this relationship is linear in layer II/III visual cortical neurons (Ogawa et al, 1981), layer V neocortical neurons (Stafstrom et al, 1984), brainstem motoneurons (Viana et al, 1995), and layer III entorhinal pyramidal neurons (Dickson et al, 1997). Interpretation of these studies is made ambiguous by the assumption that the current that reaches the soma is a linear function of the number of activated synaptic inputs.…”

Section: Comparison With Other Neuronsmentioning

confidence: 99%

The Linear Computational Algorithm of Cerebellar Purkinje Cells

Walter¹,

Khodakhah²

2006

J. Neurosci.

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The orchestration of simple motor tasks by the cerebellum results in coordinated movement and the maintenance of balance. The cerebellum integrates sensory and cortical information to generate the signals required for the coordinated execution of simple motor tasks. These signals originate in the firing rate of Purkinje cells, each of which integrates sensory and cortical information conveyed by granule cell synaptic inputs. Given the importance of the granule cell input-Purkinje cell output function for cerebellar computation, this algorithm was determined. Using several stimulation paradigms, including those that mimicked patterns of granule cell activity similar to those observed in vivo, we quantified the poststimulus maximum firing rate and number of extra spikes in response to granule cell synaptic input. Both of these parameters linearly encoded the strength of synaptic input when inhibitory synaptic transmission was blocked. This linear algorithm was independent of the location or temporal pattern of synaptic input. With inhibitory synaptic transmission intact, the maximum firing rate, but not the number of extra spikes, encoded the strength of granule cell synaptic input. Furthermore, the maximum firing rate of Purkinje cells linearly encoded the strength of synaptic input whether or not the activation of granule cells resulted in a pause in Purkinje cell firing. On the basis of the data presented, we propose that Purkinje cells encode the strength of granule cell synaptic input in their maximum firing rate with a linear algorithm.

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Membrane characteristics of visual cortical neurons in in vitro slices

Cited by 17 publications

References 9 publications

Broadband temporal stimuli decrease the integration time of neurons in cat striate cortex

Broadband temporal stimuli decrease the integration time of neurons in cat striate cortex

Interspike Intervals, Receptive Fields, and Information Encoding in Primary Visual Cortex

The Linear Computational Algorithm of Cerebellar Purkinje Cells

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