Limits...
Physiological synaptic signals initiate sequential spikes at soma of cortical pyramidal neurons.

Ge R, Qian H, Wang JH - Mol Brain (2011)

Bottom Line: In dual recordings from the soma vs. axon, the signals recorded in vivo induce somatic spikes with higher capacity, which is associated with lower somatic thresholds and shorter refractory periods mediated by voltage-gated sodium channels.The introduction of these parameters from the soma and axon into NEURON model simulates sequential spikes being somatic in origin.Physiological signals integrated from synaptic inputs primarily trigger the soma to encode neuronal digital spikes.

View Article: PubMed Central - HTML - PubMed

Affiliation: State Key Lab for Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.

ABSTRACT
The neurons in the brain produce sequential spikes as the digital codes whose various patterns manage well-organized cognitions and behaviors. A source for the physiologically integrated synaptic signals to initiate digital spikes remains unknown, which we studied at pyramidal neurons of cortical slices. In dual recordings from the soma vs. axon, the signals recorded in vivo induce somatic spikes with higher capacity, which is associated with lower somatic thresholds and shorter refractory periods mediated by voltage-gated sodium channels. The introduction of these parameters from the soma and axon into NEURON model simulates sequential spikes being somatic in origin. Physiological signals integrated from synaptic inputs primarily trigger the soma to encode neuronal digital spikes.

Show MeSH
Computational simulation based on spike thresholds and refractory periods at the soma and axon favors the sequential spikes being somatic in origin. A) The number of spikes in computational simulation is higher at the soma (red trace) than the axon (blue) induced by in vivo signal (middle). B) illustrates the number of spikes vs. the intensity of stimulus pulses at the soma (red triangle symbols) and the axon (blue circles).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3113741&req=5

Figure 6: Computational simulation based on spike thresholds and refractory periods at the soma and axon favors the sequential spikes being somatic in origin. A) The number of spikes in computational simulation is higher at the soma (red trace) than the axon (blue) induced by in vivo signal (middle). B) illustrates the number of spikes vs. the intensity of stimulus pulses at the soma (red triangle symbols) and the axon (blue circles).

Mentions: The results above indicate that long-time signals mainly inactivate axon's VGSCs and lead to the high values of spike thresholds and refractory periods. As a result, physiological signals initiate spikes being somatic in origin. To strengthen this point, we introduced the factors from the axon and soma into NEURON [27,28]. In vivo signals induced more simulated spikes at the soma (red trace in Figure 6AE) than the axon (blue). The thresholds of spikes are lower and the number of spikes by identical stimuli is higher at the soma (red symbols in Figure 6B) than the axon (blue). The result from computational simulation is consistent with those from experiments (Figure 2).


Physiological synaptic signals initiate sequential spikes at soma of cortical pyramidal neurons.

Ge R, Qian H, Wang JH - Mol Brain (2011)

Computational simulation based on spike thresholds and refractory periods at the soma and axon favors the sequential spikes being somatic in origin. A) The number of spikes in computational simulation is higher at the soma (red trace) than the axon (blue) induced by in vivo signal (middle). B) illustrates the number of spikes vs. the intensity of stimulus pulses at the soma (red triangle symbols) and the axon (blue circles).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3113741&req=5

Figure 6: Computational simulation based on spike thresholds and refractory periods at the soma and axon favors the sequential spikes being somatic in origin. A) The number of spikes in computational simulation is higher at the soma (red trace) than the axon (blue) induced by in vivo signal (middle). B) illustrates the number of spikes vs. the intensity of stimulus pulses at the soma (red triangle symbols) and the axon (blue circles).
Mentions: The results above indicate that long-time signals mainly inactivate axon's VGSCs and lead to the high values of spike thresholds and refractory periods. As a result, physiological signals initiate spikes being somatic in origin. To strengthen this point, we introduced the factors from the axon and soma into NEURON [27,28]. In vivo signals induced more simulated spikes at the soma (red trace in Figure 6AE) than the axon (blue). The thresholds of spikes are lower and the number of spikes by identical stimuli is higher at the soma (red symbols in Figure 6B) than the axon (blue). The result from computational simulation is consistent with those from experiments (Figure 2).

Bottom Line: In dual recordings from the soma vs. axon, the signals recorded in vivo induce somatic spikes with higher capacity, which is associated with lower somatic thresholds and shorter refractory periods mediated by voltage-gated sodium channels.The introduction of these parameters from the soma and axon into NEURON model simulates sequential spikes being somatic in origin.Physiological signals integrated from synaptic inputs primarily trigger the soma to encode neuronal digital spikes.

View Article: PubMed Central - HTML - PubMed

Affiliation: State Key Lab for Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.

ABSTRACT
The neurons in the brain produce sequential spikes as the digital codes whose various patterns manage well-organized cognitions and behaviors. A source for the physiologically integrated synaptic signals to initiate digital spikes remains unknown, which we studied at pyramidal neurons of cortical slices. In dual recordings from the soma vs. axon, the signals recorded in vivo induce somatic spikes with higher capacity, which is associated with lower somatic thresholds and shorter refractory periods mediated by voltage-gated sodium channels. The introduction of these parameters from the soma and axon into NEURON model simulates sequential spikes being somatic in origin. Physiological signals integrated from synaptic inputs primarily trigger the soma to encode neuronal digital spikes.

Show MeSH