Graded boosting of synaptic signals by low-threshold voltage-activated calcium conductance
Low-threshold voltage-activated calcium conductances (LT-VACCs) play a substantial role in shaping the electrophysiological attributes of neurites. We have investigated how these conductances affect synaptic integration in a premotor nonspiking (NS) neuron of the leech nervous system. These cells ex...
Guardado en:
| Publicado: |
2015
|
|---|---|
| Materias: | |
| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00223077_v114_n1_p332_Tano http://hdl.handle.net/20.500.12110/paper_00223077_v114_n1_p332_Tano |
| Aporte de: |
| id |
paper:paper_00223077_v114_n1_p332_Tano |
|---|---|
| record_format |
dspace |
| spelling |
paper:paper_00223077_v114_n1_p332_Tano2023-06-08T14:49:12Z Graded boosting of synaptic signals by low-threshold voltage-activated calcium conductance Calcium conductance Dendritic integration Nonspiking Synaptic amplification Window current animal cell Article calcium conductance controlled study electrophysiology evoked response leech motoneuron nerve cell nerve cell stimulation nervous system neurite neurophysiology nonhuman postsynaptic potential presynaptic potential priority journal sensory nerve cell spike synaptic transmission action potential animal drug effects metabolism patch clamp technique physiology synapse voltage sensitive dye imaging calcium calcium channel calcium channel blocking agent Action Potentials Animals Calcium Calcium Channel Blockers Calcium Channels Leeches Neurons Patch-Clamp Techniques Synapses Voltage-Sensitive Dye Imaging Low-threshold voltage-activated calcium conductances (LT-VACCs) play a substantial role in shaping the electrophysiological attributes of neurites. We have investigated how these conductances affect synaptic integration in a premotor nonspiking (NS) neuron of the leech nervous system. These cells exhibit an extensive neuritic tree, do not fire Na+-dependent spikes, but express an LT-VACC that was sensitive to 250 ÷M Ni2+ and 100 μM NNC 55-0396 (NNC). NS neurons responded to excitation of mechanosensory pressure neurons with depolarizing responses for which amplitude was a linear function of the presynaptic firing frequency. NNC decreased these synaptic responses and abolished the concomitant widespread Ca2+ signals. Coherent with the interpretation that the LT-VACC amplified signals at the postsynaptic level, this conductance also amplified the responses of NS neurons to direct injection of sinusoidal current. Synaptic amplification thus is achieved via a positive feedback in which depolarizing signals activate an LT-VACC that, in turn, boosts these signals. The wide distribution of LT-VACC could support the active propagation of depolarizing signals, turning the complex NS neuritic tree into a relatively compact electrical compartment. © 2015 the American Physiological Society. 2015 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00223077_v114_n1_p332_Tano http://hdl.handle.net/20.500.12110/paper_00223077_v114_n1_p332_Tano |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Calcium conductance Dendritic integration Nonspiking Synaptic amplification Window current animal cell Article calcium conductance controlled study electrophysiology evoked response leech motoneuron nerve cell nerve cell stimulation nervous system neurite neurophysiology nonhuman postsynaptic potential presynaptic potential priority journal sensory nerve cell spike synaptic transmission action potential animal drug effects metabolism patch clamp technique physiology synapse voltage sensitive dye imaging calcium calcium channel calcium channel blocking agent Action Potentials Animals Calcium Calcium Channel Blockers Calcium Channels Leeches Neurons Patch-Clamp Techniques Synapses Voltage-Sensitive Dye Imaging |
| spellingShingle |
Calcium conductance Dendritic integration Nonspiking Synaptic amplification Window current animal cell Article calcium conductance controlled study electrophysiology evoked response leech motoneuron nerve cell nerve cell stimulation nervous system neurite neurophysiology nonhuman postsynaptic potential presynaptic potential priority journal sensory nerve cell spike synaptic transmission action potential animal drug effects metabolism patch clamp technique physiology synapse voltage sensitive dye imaging calcium calcium channel calcium channel blocking agent Action Potentials Animals Calcium Calcium Channel Blockers Calcium Channels Leeches Neurons Patch-Clamp Techniques Synapses Voltage-Sensitive Dye Imaging Graded boosting of synaptic signals by low-threshold voltage-activated calcium conductance |
| topic_facet |
Calcium conductance Dendritic integration Nonspiking Synaptic amplification Window current animal cell Article calcium conductance controlled study electrophysiology evoked response leech motoneuron nerve cell nerve cell stimulation nervous system neurite neurophysiology nonhuman postsynaptic potential presynaptic potential priority journal sensory nerve cell spike synaptic transmission action potential animal drug effects metabolism patch clamp technique physiology synapse voltage sensitive dye imaging calcium calcium channel calcium channel blocking agent Action Potentials Animals Calcium Calcium Channel Blockers Calcium Channels Leeches Neurons Patch-Clamp Techniques Synapses Voltage-Sensitive Dye Imaging |
| description |
Low-threshold voltage-activated calcium conductances (LT-VACCs) play a substantial role in shaping the electrophysiological attributes of neurites. We have investigated how these conductances affect synaptic integration in a premotor nonspiking (NS) neuron of the leech nervous system. These cells exhibit an extensive neuritic tree, do not fire Na+-dependent spikes, but express an LT-VACC that was sensitive to 250 ÷M Ni2+ and 100 μM NNC 55-0396 (NNC). NS neurons responded to excitation of mechanosensory pressure neurons with depolarizing responses for which amplitude was a linear function of the presynaptic firing frequency. NNC decreased these synaptic responses and abolished the concomitant widespread Ca2+ signals. Coherent with the interpretation that the LT-VACC amplified signals at the postsynaptic level, this conductance also amplified the responses of NS neurons to direct injection of sinusoidal current. Synaptic amplification thus is achieved via a positive feedback in which depolarizing signals activate an LT-VACC that, in turn, boosts these signals. The wide distribution of LT-VACC could support the active propagation of depolarizing signals, turning the complex NS neuritic tree into a relatively compact electrical compartment. © 2015 the American Physiological Society. |
| title |
Graded boosting of synaptic signals by low-threshold voltage-activated calcium conductance |
| title_short |
Graded boosting of synaptic signals by low-threshold voltage-activated calcium conductance |
| title_full |
Graded boosting of synaptic signals by low-threshold voltage-activated calcium conductance |
| title_fullStr |
Graded boosting of synaptic signals by low-threshold voltage-activated calcium conductance |
| title_full_unstemmed |
Graded boosting of synaptic signals by low-threshold voltage-activated calcium conductance |
| title_sort |
graded boosting of synaptic signals by low-threshold voltage-activated calcium conductance |
| publishDate |
2015 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00223077_v114_n1_p332_Tano http://hdl.handle.net/20.500.12110/paper_00223077_v114_n1_p332_Tano |
| _version_ |
1768545081911934976 |