Modulatory effects of noradrenaline on the spike activity of cat motor cortex neurons under conditions of skin electrostimulation and action of extra stimuli

1994 ◽  
Vol 25 (2) ◽  
pp. 103-108
Author(s):  
A. P. Kniga ◽  
B. I. Busel
Keyword(s):  
Motor Cortex ◽  
Spike Activity

GABAergic and Glutamatergic Modulation of Spontaneous and Motor-Cortex-Evoked Complex Spike Activity

2002 ◽  
Vol 87 (4) ◽  
pp. 1993-2008 ◽  
Author(s):  
Eric J. Lang
Keyword(s):  
Motor Cortex ◽  
Banding Pattern ◽  
Spike Activity ◽  
Afferent Input ◽  
Excitatory Input ◽  
Relative Strength ◽  
Spike Synchrony ◽  
Complex Spike ◽  
Electrotonic Coupling ◽  
Inferior Olivary

Olivocerebellar activity is organized such that synchronous complex spikes occur primarily among Purkinje cells located within the same parasagittally oriented strip of cortex. Previous findings have shown that this synchrony distribution is modulated by the release of GABA and glutamate within the inferior olive, which probably act by controlling the efficacy of the electrotonic coupling between olivary neurons. The relative strengths of these two neurotransmitters in modulating the patterns of synchrony were compared by obtaining multiple electrode recordings of spontaneous crus 2a complex spike activity during intraolivary injection of solutions containing a GABAA (picrotoxin) and/or AMPA [1,2,3,4-tetrahydro-6-nitro-2,3-dioxo-benzo[f]quinoxaline-7-sulfonamide disodium (NBQX)] receptor antagonist. Injection of either antagonist led to increased synchrony between cells located within the same parasagittally oriented ≈250-μm-wide cortical strip. Picrotoxin also increased complex spike synchrony among cells located in different cortical strips, leading to a less prominent banding pattern, whereas injections of NBQX tended to decrease complex spike synchrony among such cells, enhancing the banding pattern. The relative strength of these two classes of olivary afferents was assessed by first injecting one of the antagonists alone and then in combination with the other. The enhanced banding pattern of complex spike synchrony following injection of NBQX alone remained during the subsequent combined injection of both antagonists. Furthermore, the widespread synchronization of complex spike activity following injection of picrotoxin alone was partially or completely reversed by combined injection of picrotoxin and NBQX. Changes in the climbing fiber reflex induced by the intraolivary injections paralleled the changes observed for spontaneous complex spike activity, indicating that the effects of picrotoxin and NBQX on the synchrony distribution reflect changes in the pattern of effective coupling of inferior olivary neurons and demonstrating that synchronous complex spike activity does not require simultaneous excitatory input to olivary cells. Finally the pattern of synchrony during motor cortical stimulation was examined. It was found that the patterns of synchrony for motor-cortex-evoked complex spike activity were similar to those of spontaneous activity, indicating an important role for electrotonic coupling in determining the response of the olivocerebellar system to afferent input. Moreover, intraolivary injections of picrotoxin increased the spatial distribution of the evoked response. In sum, the results provide evidence for the hypothesis that electrotonic coupling of inferior olivary neurons via gap junctions is the mechanism underlying complex spike synchrony and that this coupling plays an important role in determining the responses of the olivocerebellar system to synaptic input.

scholarly journals Fidelity of frequency and phase entrainment of circuit-level spike activity during DBS

2015 ◽  
Vol 114 (2) ◽  
pp. 825-834 ◽  
Author(s):  
Filippo Agnesi ◽  
Abirami Muralidharan ◽  
Kenneth B. Baker ◽  
Jerrold L. Vitek ◽  
Matthew D. Johnson
Keyword(s):  
Motor Cortex ◽  
Spike Activity ◽  
High Frequency ◽  
Rhesus Macaques ◽  
High Frequency Stimulation ◽  
Stimulus Pulse ◽  
Low Pass ◽  
Frequency Stimulation ◽  
Stn Dbs ◽  
Over Time

High-frequency stimulation is known to entrain spike activity downstream and upstream of several clinical deep brain stimulation (DBS) targets, including the cerebellar-receiving area of thalamus (VPLo), subthalamic nucleus (STN), and globus pallidus (GP). Less understood are the fidelity of entrainment to each stimulus pulse, whether entrainment patterns are stationary over time, and how responses differ among DBS targets. In this study, three rhesus macaques were implanted with a single DBS lead in VPLo, STN, or GP. Single-unit spike activity was recorded in the resting state in motor cortex during VPLo DBS, in GP during STN DBS, and in STN and pallidal-receiving area of motor thalamus (VLo) during GP DBS. VPLo DBS induced time-locked spike activity in 25% ( n = 15/61) of motor cortex cells, with entrained cells following 7.5 ± 7.4% of delivered pulses. STN DBS entrained spike activity in 26% ( n = 8/27) of GP cells, which yielded time-locked spike activity for 8.7 ± 8.4% of stimulus pulses. GP DBS entrained 67% ( n = 14/21) of STN cells and 32% ( n = 19/59) of VLo cells, which showed a higher fraction of pulses effectively inhibiting spike activity (82.0 ± 9.6% and 86.1 ± 16.6%, respectively). Latency of phase-locked spike activity increased over time in motor cortex (58%, VPLo DBS) and to a lesser extent in GP (25%, STN DBS). In contrast, the initial inhibitory phase observed in VLo and STN during GP DBS remained stable following stimulation onset. Together, these data suggest that circuit-level entrainment is low-pass filtered during high-frequency stimulation, most notably for glutamatergic pathways. Moreover, phase entrainment is not stationary or consistent at the circuit level for all DBS targets.

Coupled Spike Activity in Micropopulations of Motor Cortex Neurons in Rats

2010 ◽  
Vol 42 (2) ◽  
pp. 110-117 ◽  
Author(s):  
V. M. Moroz ◽  
O. V. Vlasenko ◽  
I. L. Rokunets ◽  
V. V. Chechel’ ◽  
M. V. Yoltukhovskii ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Spike Activity
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