Postsynaptic Potentials and Spike Patterns during Augmenting Responses in Cat's Motor Cortex

Klee, Manfred R.; Offenloch, Kurt

doi:10.1126/science.143.3605.488

Cited by 40 publications

(7 citation statements)

References 9 publications

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“…Upon repetitive stimulation of specific or nonspecific thalamic nuclei, an augmenting or recruiting response, respectively, could be recorded from the cortical surface (10,11). Intracellular recordings re-608 B. SUTOR AND J. J. HABLITZ vealed significant changes in the EPSP amplitude and duration (20,22,35,36). The augmenting response, evoked by repetitive stimulation of the nucleus ventralis lateralis, was associated with the appearance of a delayed second EPSP (22).…”

Section: Introductionmentioning

confidence: 99%

EPSPs in rat neocortical neurons in vitro. I. Electrophysiological evidence for two distinct EPSPs

Sutor

Hablitz

1989

Journal of Neurophysiology

134

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1. To investigate excitatory postsynaptic potentials (EPSPs), intracellular recordings were performed in layer II/III neurons of the rat medial frontal cortex. The average resting membrane potential of the neurons was more than -75 mV and their average input resistance was greater than 20 M omega. The amplitudes of the action potentials evoked by injection of depolarizing current pulses were greater than 100 mV. The electrophysiological properties of the neurons recorded were similar to those of regular-spiking pyramidal cells. 2. Current-voltage relationships, determined by injecting inward and outward current pulses, displayed considerable inward rectification in both the depolarizing and hyperpolarizing directions. The steady-state input resistance increased with depolarization and decreased with hyperpolarization, concomitant with increases and decreases, respectively, in the membrane time constant. 3. Postsynaptic potentials were evoked by electrical stimulation via a bipolar electrode positioned in layer IV of the neocortex. Stimulus-response relationships, determined by gradually increasing the stimulus intensity, were consistent among the population of neurons examined. A short-latency EPSP [early EPSP (eEPSP)] was the response with the lowest threshold. Amplitudes of the eEPSP ranged from 4 to 8 mV. Following a hyperpolarization of the membrane potential, the amplitude of the eEPSP decreased. Upon depolarization, a slight increase in amplitude and duration was observed, accompanied by a significant increase in time to peak. 4. The membrane current underlying the eEPSP (eEPSC) was measured using the single-electrode voltage-clamp method. The amplitude of the eEPSC was apparently independent of the membrane potential in 8 of 12 neurons tested. In the other 4 neurons, the amplitude of the eEPSC increased with hyperpolarization and decreased with depolarization. 5. Higher stimulus intensities evoked, in addition to the eEPSP, a delayed EPSP [late EPSP (lEPSP)] in greater than 90% of the neurons tested. The amplitude of the lEPSP ranged from 12 to 20 mV, and the latency varied between 20 and 60 ms. The amplitude of the lEPSP varied with membrane potential, decreasing with depolarization and increasing following hyperpolarization. The membrane current underlying the lEPSP (lEPSC) displayed a similar voltage dependence. 6. At stimulus intensities that led to the activation of inhibitory postsynaptic potentials (IPSPs), the lEPSP was no longer observed.(ABSTRACT TRUNCATED AT 400 WORDS)

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Section: Introductionmentioning

confidence: 99%

EPSPs in rat neocortical neurons in vitro. I. Electrophysiological evidence for two distinct EPSPs

Sutor

Hablitz

1989

Journal of Neurophysiology

134

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“…; for the thalamic VL effects, see BRANCH and MARTIN, 1958;LI,1963;KLEE and OFFENLOCH, 1964;LUx et al, 1964;NACIMIENTO et al, 1964;POLLEN, 1964;PURPURA et al, 1964;PURPURA and MCMURTRY, 1965;CREUTZFELDT et al, 1966;KLEE,1966;YOSHIDA et al, 1966;GROSSMAN et al, 1967;ARAKI and ENDO, 1976;ARAKI et al, 1976;DESCHENES and HAMMOND, 1980;DESCHENES et al, 1982). But, some superficial or middle layer cells have also been examined recently (NoDA et al, 1983;NODA and YAMAMOTO, 1984).…”

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confidence: 99%

Intracortical spread of neuronal activities induced by stimulation of recurrent and thalamic afferent pathways compared with epicortical activation.

Ezure

Oshima

1985

Jpn.J.Physiol

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1) In the encephale isole cat preparation the cerebral peduncle (CP) and the nucleus ventralis lateralis (VL) of the thalamus were stimulated. Short-latency responses recorded from precruciate cortical neurons consisted of excitatory (EPSP) and inhibitory postsynaptic potentials (IPSP). 2) Laminar distributions of these responses and their latencies were viewed as the spatiotemporal pattern of spread of excitation and inhibition within the cortex in comparison with those obtained by epicortical stimulation (EPICS). 3) In contrast with activities by EPICS spreading downwards from superficial to deep layers, CP recurrent activities spread upwards from deep to middle or superficial layers, and those by VL afferents spread from middle to both superficial and deep layers bidirectionally. 4) These three intracortical routes shared common cell assemblies in that they received convergent EPSPs or IPSPs to various extents from different inputs. The routes for EPICS and VL inputs were overlapped particularly with abundant supply of convergence in spite of their functional difference. Relevant potentiality of the cerebral network in forming plural patterns was discussed.

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“…A form of the superficial T-C response is the recruiting response as mentioned previously. Suggestions have also been made by some authors that the augmenting response might contain in itself an identical component with the recruiting response (BISHOP et al, 1961 ;KLEE and OFFENLOCH, 1964).…”

Section: Discussionmentioning

confidence: 99%

“…Various attempts have been made to characterize more clearly the responses. Studies with intracellular recordings from cortical neurones have elucidated some changes in membrane potentials concomitant with the responses recorded with gross electrodes (Li, 1963 ;KLEE and OFFENLOCH, 1964;PURPURA and SHOFER, 1964;NACIMIENTO et al, 1964;CREUTZFELDT et al, 1966). However, more decisive characterization of the responses was successfully attained by means of laminar field potential recordings (LI et al, 1956;SPENCER and BROOKHART, 1961;SASAKI et al, 1970).…”

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confidence: 99%

Examination of Responses Evoked in the Sensory Cortex by Thalamic Stimulation

1972

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Summary 1) Augmenting and recruiting responses in the sensory cortices were examined by means of laminar field potential analysis in the cortices. These responses were characterized and interpreted as follows : Augmenting responses are a deep thalamocortical (T-C) response followed by a superficial T-C response and recruiting responses ` are a pure form of superficial T-C response, deep and superficial T-C responses being two elementary components constituting various cortical responses induced by thalamic stimulation (see SASAKI et al., 1970). 2) Long-latency surface-negative potentials elicited in the somatosensory cortex (posterior sigmoid gyrus) by repetitive stimulation of the intralaminar thalamic nuclei were not due to recruiting responses actually generated in this area but attributable to the responses evoked in the underlying hidden cortex. Similar situations to those in the somatosensory cortex hold for "recruiting responses" recorded on the surface of the visual and auditory areas, i.e., the responses in the lateral and the ectosylvian gyri were assignable to activities generated in the underlying or neighboring hidden cortex. 3) Repetitive stimulation of the thalamic sensory relay nuclei given at a low frequency failed to evoke the augmenting response in the respective cortical sensory areas. It induced in some cases incremental responses in the sensory areas of the cortex ; the depth profiles in the cortex were not in accord with the characteristic feature of the augmenting response in the anterior sigmoid gyrus. 4) The absence of superficial T-C responses in the form of recruiting responses as well as a component of augmenting responses in the sensory cortices suggests that there is little or no thalamocortical projection system for the superficial T-C response ending in these cortices.

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Postsynaptic Potentials and Spike Patterns during Augmenting Responses in Cat's Motor Cortex

Cited by 40 publications

References 9 publications

EPSPs in rat neocortical neurons in vitro. I. Electrophysiological evidence for two distinct EPSPs

EPSPs in rat neocortical neurons in vitro. I. Electrophysiological evidence for two distinct EPSPs

Intracortical spread of neuronal activities induced by stimulation of recurrent and thalamic afferent pathways compared with epicortical activation.

Examination of Responses Evoked in the Sensory Cortex by Thalamic Stimulation

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